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What is PUBLIC-KEY CRYPTOGRAPHY? What does PUBLIC-KEY CRYPTOGRAPHY mean? PUBLIC-KEY CRYPTOGRAPHY meaning - PUBLIC-KEY CRYPTOGRAPHY definition - PUBLIC-KEY CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Public-key cryptography, or asymmetric cryptography, is any cryptographic system that uses pairs of keys: public keys that may be disseminated widely paired with private keys which are known only to the owner. There are two functions that can be achieved: using a public key to authenticate that a message originated with a holder of the paired private key; or encrypting a message with a public key to ensure that only the holder of the paired private key can decrypt it. In a public-key encryption system, any person can encrypt a message using the public key of the receiver, but such a message can be decrypted only with the receiver's private key. For this to work it must be computationally easy for a user to generate a public and private key-pair to be used for encryption and decryption. The strength of a public-key cryptography system relies on the degree of difficulty (computational impracticality) for a properly generated private key to be determined from its corresponding public key. Security then depends only on keeping the private key private, and the public key may be published without compromising security. Public-key cryptography systems often rely on cryptographic algorithms based on mathematical problems that currently admit no efficient solution—particularly those inherent in certain integer factorization, discrete logarithm, and elliptic curve relationships. Public key algorithms, unlike symmetric key algorithms, do not require a secure channel for the initial exchange of one (or more) secret keys between the parties. Because of the computational complexity of asymmetric encryption, it is usually used only for small blocks of data, typically the transfer of a symmetric encryption key (e.g. a session key). This symmetric key is then used to encrypt the rest of the potentially long message sequence. The symmetric encryption/decryption is based on simpler algorithms and is much faster. Message authentication involves hashing the message to produce a "digest," and encrypting the digest with the private key to produce a digital signature. Thereafter anyone can verify this signature by (1) computing the hash of the message, (2) decrypting the signature with the signer's public key, and (3) comparing the computed digest with the decrypted digest. Equality between the digests confirms the message is unmodified since it was signed, and that the signer, and no one else, intentionally performed the signature operation — presuming the signer's private key has remained secret. The security of such procedure depends on a hash algorithm of such quality that it is computationally impossible to alter or find a substitute message that produces the same digest - but studies have shown that even with the MD5 and SHA-1 algorithms, producing an altered or substitute message is not impossible. The current hashing standard for encryption is SHA-2. The message itself can also be used in place of the digest. Public-key algorithms are fundamental security ingredients in cryptosystems, applications and protocols. They underpin various Internet standards, such as Transport Layer Security (TLS), S/MIME, PGP, and GPG. Some public key algorithms provide key distribution and secrecy (e.g., Diffie–Hellman key exchange), some provide digital signatures (e.g., Digital Signature Algorithm), and some provide both (e.g., RSA). Public-key cryptography finds application in, among others, the information technology security discipline, information security. Information security (IS) is concerned with all aspects of protecting electronic information assets against security threats. Public-key cryptography is used as a method of assuring the confidentiality, authenticity and non-repudiability of electronic communications and data storage.
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What is KEY DISTRIBUTION? What does KEY DISTRIBUTION mean? KEY DISTRIBUTION meaning - KEY DISTRIBUTION definition - KEY DISTRIBUTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In symmetric key cryptography, both parties must possess a secret key which they must exchange prior to using any encryption. Distribution of secret keys has been problematic until recently, because it involved face-to-face meeting, use of a trusted courier, or sending the key through an existing encryption channel. The first two are often impractical and always unsafe, while the third depends on the security of a previous key exchange. In public key cryptography, the key distribution of public keys is done through public key servers. When a person creates a key-pair, they keep one key private and the other, known as the public-key, is uploaded to a server where it can be accessed by anyone to send the user a private, encrypted, message. Secure Sockets Layer (SSL) uses Diffie–Hellman key exchange if the client does not have a public-private key pair and a published certificate in the public key infrastructure, and Public Key Cryptography if the user does have both the keys and the credential. Key distribution is an important issue in wireless sensor network (WSN) design. There are many key distribution schemes in the literature that are designed to maintain an easy and at the same time secure communication among sensor nodes. The most accepted method of key distribution in WSNs is key predistribution, where secret keys are placed in sensor nodes before deployment. When the nodes are deployed over the target area, the secret keys are used to create the network. For more info see: key distribution in wireless sensor networks. Key distribution and key storage are more problematic in the cloud due to the transitory nature of the agents on it. Secret sharing can be used to store keys at many different servers on the cloud. In secret sharing, a secret is used as a seed to generate a number of distinct secrets, and the pieces are distributed so that some subset of the recipients can jointly authenticate themselves and use the secret information without learning what it is. But rather than store files on different servers, the key is parceled out and its secret shares stored at multiple locations in a manner that a subset of the shares can regenerate the key. Secret sharing is used in cases where one wishes to distribute a secret among N shares so that M N of them (M of N) can regenerate the original secret, but no smaller group up to M - 1 can do so.
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What is HYBRID CRYPTOSYSTEM? What does HYBRID CRYPTOSYSTEM mean? HYBRID CRYPTOSYSTEM meaning - HYBRID CRYPTOSYSTEM definition - HYBRID CRYPTOSYSTEM explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a hybrid cryptosystem is one which combines the convenience of a public-key cryptosystem with the efficiency of a symmetric-key cryptosystem. Public-key cryptosystems are convenient in that they do not require the sender and receiver to share a common secret in order to communicate securely (among other useful properties). However, they often rely on complicated mathematical computations and are thus generally much more inefficient than comparable symmetric-key cryptosystems. In many applications, the high cost of encrypting long messages in a public-key cryptosystem can be prohibitive. This is addressed by hybrid systems by using a combination of both. A hybrid cryptosystem can be constructed using any two separate cryptosystems: a key encapsulation scheme, which is a public-key cryptosystem, and a data encapsulation scheme, which is a symmetric-key cryptosystem. The hybrid cryptosystem is itself a public-key system, whose public and private keys are the same as in the key encapsulation scheme. Note that for very long messages the bulk of the work in encryption/decryption is done by the more efficient symmetric-key scheme, while the inefficient public-key scheme is used only to encrypt/decrypt a short key value. All practical implementations of public key cryptography today employ the use of a hybrid system. Examples include the TLS protocol which uses a public-key mechanism for key exchange (such as Diffie-Hellman) and a symmetric-key mechanism for data encapsulation (such as AES). The OpenPGP (RFC 4880) file format and the PKCS #7 (RFC 2315) file format are other examples. Example: To encrypt a message addressed to Alice in a hybrid cryptosystem, Bob does the following: 1. Obtains Alice's public key. 2. Generates a fresh symmetric key for the data encapsulation scheme. 3. Encrypts the message under the data encapsulation scheme, using the symmetric key just generated. 4. Encrypt the symmetric key under the key encapsulation scheme, using Alice's public key. 5. Send both of these encryptions to Alice. To decrypt this hybrid ciphertext, Alice does the following: Uses her private key to decrypt the symmetric key contained in the key encapsulation segment. Uses this symmetric key to decrypt the message contained in the data encapsulation segment. If both the key encapsulation and data encapsulation schemes are secure against adaptive chosen ciphertext attacks, then the hybrid scheme inherits that property as well. However, it is possible to construct a hybrid scheme secure against adaptive chosen ciphertext attack even if the key encapsulation has a slightly weakened security definition (though the security of the data encapsulation must be slightly stronger).
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What is ID-BASED CRYPTOGRAPHY? What does ID-BASED CRYPTOGRAPHY mean? ID-BASED CRYPTOGRAPHY meaning - ID-BASED CRYPTOGRAPHY definition - ID-BASED CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Identity-based cryptography is a type of public-key cryptography in which a publicly known string representing an individual or organization is used as a public key. The public string could include an email address, domain name, or a physical IP address. The first implementation of identity-based signatures and an email-address based public-key infrastructure (PKI) was developed by Adi Shamir in 1984, which allowed users to verify digital signatures using only public information such as the user's identifier. Under Shamir's scheme, a trusted third party would deliver the private key to the user after verification of the user's identity, with verification essentially the same as that required for issuing a certificate in a typical PKI. Shamir similarly proposed identity-based encryption, which appeared particularly attractive since there was no need to acquire an identity's public key prior to encryption. However, he was unable to come up with a concrete solution, and identity-based encryption remained an open problem for many years. The first practical implementations were finally devised by Sakai in 2000, and Boneh and Franklin in 2001. These solutions were based on bilinear pairings. Also in 2001, a solution was developed independently by Clifford Cocks. Identity-based systems allow any party to generate a public key from a known identity value such as an ASCII string. A trusted third party, called the private key generator (PKG), generates the corresponding private keys. To operate, the PKG first publishes a master public key, and retains the corresponding master private key (referred to as master key). Given the master public key, any party can compute a public key corresponding to the identity ID by combining the master public key with the identity value. To obtain a corresponding private key, the party authorized to use the identity ID contacts the PKG, which uses the master private key to generate the private key for identity ID. Identity-based systems have a characteristic problem in operation. Suppose Alice and Bob are users of such a system. Since the information needed to find Alice's public key is completely determined by Alice's ID and the master public key, it is not possible to revoke Alice's credentials and issue new credentials without either (a) changing Alice's ID (usually a phone number or an email address which will appear in a corporate directory); or (b) changing the master public key and re-issusing private keys to all users, including Bob. This limitation may be overcome by including a time component (e.g. the current month) in the identity.
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What is PRE-SHARED KEY? What does PRE-SHARED KEY mean? PRE-SHARED KEY meaning - PRE-SHARED KEY definition - PRE-SHARED KEY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a pre-shared key (PSK) is a shared secret which was previously shared between the two parties using some secure channel before it needs to be used. To build a key from shared secret, the key derivation function is typically used. Such systems almost always use symmetric key cryptographic algorithms. The term PSK is used in Wi-Fi encryption such as Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), where the method is called WPA-PSK or WPA2-PSK, and also in the Extensible Authentication Protocol (EAP), where it is known as EAP-PSK. In all these cases, both the wireless access points (AP) and all clients share the same key. The characteristics of this secret or key are determined by the system which uses it; some system designs require that such keys be in a particular format. It can be a password, a passphrase, or a hexadecimal string. The secret is used by all systems involved in the cryptographic processes used to secure the traffic between the systems. Crypto systems rely on one or more keys for confidentiality. One particular attack is always possible against keys, the brute force key space search attack. A sufficiently long, randomly chosen, key can resist any practical brute force attack, though not in principle if an attacker has sufficient computational power (see password strength and password cracking for more discussion). Unavoidably, however, pre-shared keys are held by both parties to the communication, and so can be compromised at one end, without the knowledge of anyone at the other. There are several tools available to help one choose strong passwords, though doing so over any network connection is inherently unsafe as one cannot in general know who, if anyone, may be eavesdropping on the interaction. Choosing keys used by cryptographic algorithms is somewhat different in that any pattern whatsoever should be avoided, as any such pattern may provide an attacker with a lower effort attack than brute force search. This implies random key choice to force attackers to spend as much effort as possible; this is very difficult in principle and in practice as well. As a general rule, any software except a Cryptographically secure pseudorandom number generator should be avoided.
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What is CERTIFICATE-BASED ENCRYPTION? What does CERTIFICATE-BASED ENCRYPTION mean? CERTIFICATE-BASED ENCRYPTION meaning - CERTIFICATE-BASED ENCRYPTION definition - CERTIFICATE-BASED ENCRYPTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Certificate-based encryption is a system in which a certificate authority uses ID-based cryptography to produce a certificate. This system gives the users both implicit and explicit certification, the certificate can be used as a conventional certificate (for signatures, etc.), but also implicitly for the purpose of encryption. A user Alice can doubly encrypt a message using another user's (Bob) public key and his (Bob's) identity. This means that the user (Bob) cannot decrypt it without a currently valid certificate and also that the certificate authority cannot decrypt the message as they don't have the user's private key (i.e., there is no implicit escrow as with ID-based cryptography, as the double encryption means they cannot decrypt it solely with the information they have).Certificate is the trust between two parties. Key revocation can be added to the system by requiring a new certificate to be issued as frequently as the level of security requires. Because the certificate is "public information", it does not need to be transmitted over a secret channel. The downside of this is the requirement for regular communication between users and the certificate authority, which means the certificate authority is more vulnerable to electronic attacks (such as denial-of-service attacks) and also that such attacks could effectively stop the system from working. This risk can be partially but not completely reduced by having a hierarchy of multiple certificate authorities. The best example of practical use of certificate-based encryption is Content Scrambling System (CSS), which is used to encode DVD movies in such a way as to make them playable only in a part of the world where they are sold. However, the fact that the region decryption key is stored on the hardware level in the DVD players substantially weakens this form of protection.
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What is CHAOTIC CRYPTOLOGY? What does CHAOTIC CRYPTOLOGY mean? CHAOTIC CRYPTOLOGY meaning - CHAOTIC CRYPTOLOGY definition - CHAOTIC CRYPTOLOGY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Chaotic cryptography is the application of the mathematical chaos theory to the practice of the cryptography, the study or techniques used to privately and securely transmit information with the presence of a third-party or adversary. The use of chaos or randomness in cryptography has long been sought after by entities wanting a new way to encrypt messages. However, because of the lack of thorough, provable security properties and low acceptable performance, chaotic cryptography has encountered setbacks. In order to use chaos theory efficiently in cryptography, the chaotic maps should be implemented such that the entropy generated by the map can produce required Confusion and diffusion. Properties in chaotic systems and cryptographic primitives share unique characteristics that allow for the chaotic systems to be applied to cryptography. If chaotic parameters, as well as cryptographic keys, can be mapped symmetrically or mapped to produce acceptable and functional outputs, it will make it next to impossible for an adversary to find the outputs without any knowledge of the initial values. Since chaotic maps in a real life scenario require a set of numbers that are limited, they may, in fact, have no real purpose in a cryptosystem if the chaotic behavior can be predicted. One of the most important issues for any cryptographic primitive is the security of the system. However, in numerous cases, chaos-based cryptography algorithms are proved unsecure. The main issue in many of the cryptanalyzed algorithms is the inadequacy of the chaotic maps implemented in the system. The concept of chaos cryptography or in the other words chaos-based cryptography can be divided into two major groups: the asymmetric and symmetric chaos-based cryptography. The majority of the symmetric chaos-based algorithms are based on the application of discrete chaotic maps in their process. Bourbakis and Alexopoulos in 1991 proposed supposedly the earliest fully intended digital image encryption scheme which was based on SCAN language. Later on, with the emergence of chaos-based cryptography hundreds of new image encryption algorithms, all with the aim of improving the security of digital images were proposed. However, there were three main aspects of the design of an image encryption that was usually modified in different algorithms (chaotic map, application of the map and structure of algorithm). The initial and perhaps most crucial point was the chaotic map applied in the design of the algorithms. The speed of the cryptosystem is always an important parameter in the evaluation of the efficiency of a cryptography algorithm, therefore, the designers were initially interested in using simple chaotic maps such as tent map, and the logistic map. However, in 2006 and 2007, the new image encryption algorithms based on more sophisticated chaotic maps proved that application of chaotic map with higher dimension could improve the quality and security of the cryptosystems. The unpredictable behavior of the chaotic maps can be used in the generation of random numbers. Some of the earliest chaos-based random number generators try to directly generate random numbers form the logistic map.
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What is POST-QUANTUM CRYPTOGRAPHY? What does POST-QUANTUM CRYPTOGRAPHY mean? POST-QUANTUM CRYPTOGRAPHY meaning - POST-QUANTUM CRYPTOGRAPHY definition - POST-QUANTUM CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Post-quantum cryptography refers to cryptographic algorithms (usually public-key algorithms) that are thought to be secure against an attack by a quantum computer. This is not true for the most popular public-key algorithms, which can be efficiently broken by a sufficiently large quantum computer. The problem with the currently popular algorithms is that their security relies on one of three hard mathematical problems: the integer factorization problem, the discrete logarithm problem or the elliptic-curve discrete logarithm problem. All of these problems can be easily solved on a sufficiently powerful quantum computer running Shor's algorithm. Even though current, publicly known, experimental quantum computers are too small to attack any real cryptographic algorithm, many cryptographers are designing new algorithms to prepare for a time when quantum computing becomes a threat. This work has gained greater attention from academics and industry through the PQCrypto conference series since 2006 and more recently by several workshops on Quantum Safe Cryptography hosted by the European Telecommunications Standards Institute (ETSI) and the Institute for Quantum Computing. In contrast to the threat quantum computing poses to current public-key algorithms, most current symmetric cryptographic algorithms and hash functions are considered to be relatively secure against attacks by quantum computers. While the quantum Grover's algorithm does speed up attacks against symmetric ciphers, doubling the key size can effectively block these attacks. Thus post-quantum symmetric cryptography does not need to differ significantly from current symmetric cryptography.
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What is QUANTUM KEY DISTRIBUTION? What does QUANTUM KEY DISTRIBUTION mean? QUANTUM KEY DISTRIBUTION meaning - QUANTUM KEY DISTRIBUTION definition - QUANTUM KEY DISTRIBUTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the best-known example of a quantum cryptographic task. An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented that detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted. The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography, which relies on the computational difficulty of certain mathematical functions, and cannot provide any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy. Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real-world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm.
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What is CRYPTO PHONE? What does CRYPTO PHONE mean? CRYPTO PHONE meaning - CRYPTO PHONE definition - CRYPTO PHONE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Crypto phones are mobile telephones that provide security against eavesdropping and electronic surveillance. The interception of telecommunications has become a major industry. Most of the world's intelligence agencies and many private organisations intercept telephone communications to obtain military, economic and political information. The price of simple mobile phone surveillance devices has become so low that many individuals can afford to use them. Advances in technology have made it difficult to determine who is intercepting and recording private communications. Crypto phones can protect calls from interception by using algorithms to encrypt the signals. The phones have a cryptographic chip that handles encryption and decryption. Two algorithms are programmed into the chip: A key-exchange algorithm for the key agreement protocol and a symmetric-key algorithm for voice encryption. For the system to work, both users must have crypto phones logged into crypto mode. As with other phones, the signal is encrypted by GSM but it is also encrypted by the cryptographic chip. When the IMSI-catcher performs a man-in-the-middle attack and disables the GSM encryption, the crypto phone encryption remains intact. Therefore, while the signal is still being intercepted, it can no longer be decoded and fake SMS messages can't be sent as the IMSI-catcher does not have the correct code. At the beginning of the call, both users get the same session key by using the hash function. Then the session key becomes a confirm code. The confirm code could be 3 letters or 4 numbers, depending on the phone's manufacturer. In the crypto mode, the user reads the confirm code over the encrypted line to his communication partner and verifies the confirm code his partner reads back. If there is a discrepancy in the confirm code, a man-in-the-middle attack has been detected. The "session code" that has been established is used only for that specific call. At termination, all the parameters are wiped from memory, and there is no way to reconstruct the code. Intercepted and stored encrypted material can be kept for later analysis, but there is no way to break the code except, possibly, by the time consuming trial-and-error method.
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What is NONREPUDIATION? What does NONREPUDIATION mean? NONREPUDIATION meaning - NONREPUDIATION pronunciation - NONREPUDIATION definition - NONREPUDIATION explanation - How to pronounce NONREPUDIATION? Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Non-repudiation refers to a state of affairs where the author of a statement will not be able to successfully challenge the authorship of the statement or validity of an associated contract. The term is often seen in a legal setting wherein the authenticity of a signature is being challenged. In such an instance, the authenticity is being "repudiated". In a general sense non-repudiation involves associating actions or changes to a unique individual. For a secure area, for example, it may be desirable to implement a key card access system. Non-repudiation would be violated if it were not also a strictly enforced policy to prohibit sharing of the key cards and to immediately report lost or stolen cards. Otherwise determining who performed the action of opening the door cannot be trivially determined. Similarly, for computer accounts, the individual owner of the account must not allow others to use that account, especially, for instance, by giving away their account's password, and a policy should be implemented to enforce this. This prevents the owner of the account from denying actions performed by the account. Regarding digital security, the cryptological meaning and application of non-repudiation shifts to mean: A service that provides proof of the integrity and origin of data. An authentication that can be asserted to be genuine with high assurance. Proof of data integrity is typically the easiest of these requirements to accomplish. A data hash, such as SHA2, is usually sufficient to establish that the likelihood of data being undetectably changed is extremely low. Even with this safeguard, it is still possible to tamper with data in transit, either through a man-in-the-middle attack or phishing. Due to this flaw, data integrity is best asserted when the recipient already possesses the necessary verification information. The most common method of asserting the digital origin of data is through digital certificates, a form of public key infrastructure to which digital signatures belong. Note that the public key scheme is not used for encryption in this form; i.e. the goal is not to achieve confidentiality, since a message signed with a private key can be read by anyone using the public key. Verifying the digital origin means that the certified/signed data can be, with reasonable certainty, trusted to be from somebody who possesses the private key corresponding to the signing certificate. If the key is not properly safeguarded by the original owner, digital forgery can become a major concern. The ways in which a party may attempt to repudiate a signature present a challenge to the trustworthiness of the signatures themselves. The standard approach to mitigating these risks is to involve a trusted third party. The two most common TTPs are forensic analysts and notaries. A forensic analyst specializing in handwriting can look at a signature, compare it to a known valid signature, and make a reasonable assessment of the legitimacy of the first signature. A notary provides a witness whose job is to verify the identity of an individual by checking other credentials and affixing their certification that the party signing is who they claim to be. Further, a notary provides the extra benefit of maintaining independent logs of their transactions, complete with the type of credential checked and another signature that can independently be verified by the preceding forensic analyst. For this double security, notaries are the preferred form of verification. On the digital side, the only TTP is the repository for public key certificates. This provides the recipient with the ability to verify the origin of an item even if no direct exchange of the public information has ever been made. The digital signature, however, is forensically identical in both legitimate and forged uses - if someone possesses the private key they can create a "real" signature. The protection of the private key is the idea behind the United States Department of Defense's Common Access Card (CAC), which never allows the key to leave the card and therefore necessitates the possession of the card in addition to the personal identification number (PIN) code necessary to unlock the card for permission to use it for encryption and digital signatures.
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What is KLEPTOGRAPHY? What does KLEPTOGRAPHY mean? KLEPTOGRAPHY meaning - KLEPTOGRAPHY pronunciation - KLEPTOGRAPHY definition - KLEPTOGRAPHY explanation - How to pronounce KLEPTOGRAPHY? Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Kleptography is the study of stealing information securely and subliminally and it was introduced by Adam Young and Moti Yung in the Proceedings of Advances in Cryptology—Crypto '96. Kleptography is a subfield of cryptovirology and is a natural extension of the theory of subliminal channels that was pioneered by Gus Simmons while at Sandia National Laboratory. A kleptographic backdoor is synonymously referred to as an asymmetric backdoor. Kleptography encompasses secure and covert communications through cryptosystems and cryptographic protocols. This is reminiscent of, but not the same as steganography that studies covert communications through graphics, video, digital audio data, and so forth. A kleptographic attack is an attack which uses asymmetric cryptography to implement a cryptographic backdoor. For example, one such attack could be to subtly modify how the public and private key pairs are generated by the cryptosystem so that the private key could be derived from the public key using the attacker's private key. In a well-designed attack, the outputs of the infected cryptosystem would be computationally indistinguishable from the outputs of the corresponding uninfected cryptosystem. If the infected cryptosystem is a black-box implementation such as a hardware security module, a smartcard, or a Trusted Platform Module, a successful attack could go completely unnoticed. A reverse engineer might be able to uncover a backdoor inserted by an attacker, and when it is a symmetric backdoor, even use it herself. However, by definition a kleptographic backdoor is asymmetric and the reverse-engineer cannot use it. A kleptographic attack (asymmetric backdoor) requires a private key known only to the attacker in order to use the backdoor. In this case, even if the reverse engineer was well-funded and gained complete knowledge of the backdoor, it would remain useless for her to extract the plaintext without the attacker's private key. Kleptographic attacks can be constructed as a cryptotrojan that infects a cryptosystem and opens a backdoor for the attacker, or can be implemented by the manufacturer of a cryptosystem. The attack does not necessarily have to reveal the entirety of the cryptosystem's output; a more complicated attack technique may alternate between producing uninfected output and insecure data with the backdoor present. Kleptographic attacks have been designed for RSA key generation, the Diffie–Hellman key exchange, the Digital Signature Algorithm, and other cryptographic algorithms and protocols. SSL, SSH, and IPsec protocols are vulnerable to kleptographic attacks. In each case, the attacker is able to compromise the particular cryptographic algorithm or protocol by inspecting the information that the backdoor information is encoded in (e.g., the public key, the digital signature, the key exchange messages, etc.) and then exploiting the logic of the asymmetric backdoor using their secret key (usually a private key). A. Juels and J. Guajardo proposed a method (KEGVER) through which a third party can verify RSA key generation. This is devised as a form of distributed key generation in which the secret key is only known to the black box itself. This assures that the key generation process was not modified and that the private key cannot be reproduced through a kleptographic attack.
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What is MESSAGE AUTHENTICATION? What does MESSAGE AUTHENTICATION mean? MESSAGE AUTHENTICATION meaning - MESSAGE AUTHENTICATION definition - MESSAGE AUTHENTICATION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In information security, message authentication or data origin authentication is a property that a message has not been modified while in transit (data integrity) and that the receiving party can verify the source of the message. Message authentication does not necessarily include the property of non-repudiation. Message authentication is typically achieved by using message authentication codes (MACs), authenticated encryption (AE) or digital signatures. Some cryptographers distinguish between "message authentication without secrecy" systems -- which allow the intended receiver to verify the source of the message, but don't bother hiding the plaintext contents of the message -- from authenticated encryption systems. A few cryptographers have researched subliminal channel systems that send messages that appear to use a "message authentication without secrecy" system, but in fact also transmit a secret message.
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What is DATA IN USE? What does DATA IN USE mean? DATA IN USE meaning - DATA IN USE definition - DATA IN USE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Data in use is an information technology term referring to active data which is stored in a non-persistent digital state typically in computer random access memory (RAM), CPU caches, or CPU registers. Data in use is used as a complement to the terms data in transit and data at rest which together define the three states of digital data. While data in use most commonly refers to data in computer memory, some Cloud Software-as-a-Service (SaaS) providers refer to data in use as any data currently being processed by applications. Because of its nature, Data in Use is of increasing concern to businesses, government agencies and other institutions. Data in use, or memory, can contain sensitive data including digital certificates, encryption keys, intellectual property (software algorithms, design data), and personally identifiable information. Compromising data in use enables access to encrypted data at rest and data in motion. For example, someone with access to random access memory can parse that memory to locate the encryption key for data at rest. Once they have obtained that encryption key, they can decrypt encrypted data at rest. Threats to data in use can come in the form of cold boot attacks, malicious hardware devices, and bootkits. Encryption, which prevents data visibility in the event of its unauthorized access or theft, is commonly used to protect Data in Motion and Data at Rest and increasingly recognized as an optimal method for protecting Data in Use. There have been multiple projects to encrypt memory. Microsoft Xbox systems are designed to provide memory encryption and the company PrivateCore presently has a commercial software product vCage to provide attestation along with full memory encryption for x86 servers. Several papers have been published highlighting the availability of security-enhanced x86 and ARM commodity processors. In that work, an ARM Cortex A8 processor is used as the substrate on which a full memory encryption solution is built. Process segments (for example, stack, code or heap) can be encrypted individually or in composition. This work marks the first full memory encryption implementation on a mobile general-purpose commodity processor. The system provides both confidentiality and integrity protections of code and data which are encrypted everywhere outside the CPU boundary. Operating system kernel patches such as TRESOR and Loop-Amnesia modify the operating system so that CPU registers can be used to store encryption keys and avoid holding encryption keys in RAM. While this approach is not general purpose and does not protect all data in use, it does protect against cold boot attacks. Encryption keys are held inside the CPU rather than in RAM so that data at rest encryption keys are protected against attacks that might compromise encryption keys in memory. Enclaves enable an “enclave” to be secured with encryption in RAM so that enclave data is encrypted while in RAM but available as clear text inside the CPU and CPU cache. Intel Corporation has introduced the concept of “enclaves” as part of its Software Guard Extensions. Intel revealed an architecture combining software and CPU hardware in technical papers published in 2013. Several cryptographic tools, including secure multi-party computation and homomorphic encryption, allow for the private computation of data on untrusted systems. Data in use could be operated upon while encrypted and never exposed to the system doing the processing.
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~~~ Encryption ~~~ Title: What is Encryption? Explain Encryption, Define Encryption, Meaning of Encryption Created on: 2018-08-22 Source Link: https://en.wikipedia.org/wiki/Encryption ------ Description: In cryptography, encryption is the process of encoding a message or information in such a way that only authorized parties can access it and those who are not authorized cannot. Encryption does not itself prevent interference, but denies the intelligible content to a would-be interceptor. In an encryption scheme, the intended information or message, referred to as plaintext, is encrypted using an encryption algorithm – a cipher – generating ciphertext that can be read only if decrypted. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is in principle possible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users. ------ To see your favorite topic here, fill out this request form: https://docs.google.com/forms/d/e/1FAIpQLScU0dLbeWsc01IC0AaO8sgaSgxMFtvBL31c_pjnwEZUiq99Fw/viewform ------ Source: Wikipedia.org articles, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Support: Donations can be made from https://wikimediafoundation.org/wiki/Ways_to_Give to support Wikimedia Foundation and knowledge sharing.
Views: 29 Audioversity

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What is QUANTUM CRYPTOGRAPHY? What does QUANTUM CRYPTOGRAPHY mean? QUANTUM CRYPTOGRAPHY meaning - QUANTUM CRYPTOGRAPHY definition - QUANTUM CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks. The best known example of quantum cryptography is quantum key distribution which offers an information-theoretically secure solution to the key exchange problem. Currently used popular public-key encryption and signature schemes (e.g., RSA and ElGamal) can be broken by quantum adversaries. The advantage of quantum cryptography lies in the fact that it allows the completion of various cryptographic tasks that are proven or conjectured to be impossible using only classical (i.e. non-quantum) communication (see below for examples). For example, it is impossible to copy data encoded in a quantum state and the very act of reading data encoded in a quantum state changes the state. This is used to detect eavesdropping in quantum key distribution. History: Quantum cryptography uses Heisenberg's uncertainty principle formulated in 1927, and the No-cloning theorem first articulated by Wootters and Zurek and Dieks in 1982. Werner Heisenberg discovered one of the fundamental principles of quantum mechanics: "At the instant at which the position of the electron is known, its momentum therefore can be known only up to magnitudes which correspond to that discontinuous change; thus, the more precisely the position is determined, the less precisely the momentum is known, and conversely” (Heisenberg, 1927: 174–5). This simply means that observation of quanta changes its behavior. By measuring the velocity of quanta we would affect it, and thereby change its position; if we want to find a quant's position, we are forced to change its velocity. Therefore, we cannot measure a quantum system's characteristics without changing it (Clark, n.d.) and we cannot record all characteristics of a quantum system before those characteristics are measured. The No-cloning theorem demonstrates that it is impossible to create a copy of an arbitrary unknown quantum state. This makes unobserved eavesdropping impossible because it will be quickly detected, thus greatly improving assurance that the communicated data remains private. Quantum cryptography was proposed first by Stephen Wiesner, then at Columbia University in New York, who, in the early 1970s, introduced the concept of quantum conjugate coding. His seminal paper titled "Conjugate Coding" was rejected by IEEE Information Theory Society, but was eventually published in 1983 in SIGACT News (15:1 pp. 78–88, 1983). In this paper he showed how to store or transmit two messages by encoding them in two "conjugate observables", such as linear and circular polarization of light, so that either, but not both, of which may be received and decoded. He illustrated his idea with a design of unforgeable bank notes. In 1984, building upon this work, Charles H. Bennett, of the IBM's Thomas J. Watson Research Center, and Gilles Brassard, of the Université de Montréal, proposed a method for secure communication based on Wiesner's "conjugate observables", which is now called BB84. In 1991 Artur Ekert developed a different approach to quantum key distribution based on peculiar quantum correlations known as quantum entanglement. Random rotations of the polarization by both parties (usually called Alice and Bob) have been proposed in Kak's three-stage quantum cryptography protocol. In principle, this method can be used for continuous, unbreakable encryption of data if single photons are used. The basic polarization rotation scheme has been implemented. The BB84 method is at the basis of quantum key distribution methods. Companies that manufacture quantum cryptography systems include MagiQ Technologies, Inc. (Boston, Massachusetts, United States), ID Quantique (Geneva, Switzerland), QuintessenceLabs (Canberra, Australia) and SeQureNet (Paris, France).
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What is PAPER KEY? What does PAPER KEY mean? PAPER KEY meaning - PAPER KEY definition - PAPER KEY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ A paper key is a machine-readable print of a cryptographic key. The printed key can be used to decrypt data, e.g. archives or backup data. A paper key can be the result of an offline private key protocol. The offline private key can also function as a token in two-factor authentication. The idea is that a digital key to decrypt and recover sensitive or personal data should have long-term durability and not be stored on any computer or network. The length of secure cryptographic keys restricts memorization, so the secret key takes the form of a 2D barcode, a machine-readable print. Early implementations of a paper key by the company Safeberg use a Data Matrix barcode. or human-readable base 16 digits. The user stores the printed key in a secure location. To avoid abuse, the key can only be used in combination with a ‘normal’ password. The user can extract the key by creating a digital photo or scan of their paper key and feeding it to cryptographic software that extracts the key to decrypt the data.
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What is CRYPTOVIROLOGY? What does CRYPTOVIROLOGY mean? CRYPTOVIROLOGY meaning - CRYPTOVIROLOGY pronunciation - CRYPTOVIROLOGY definition - CRYPTOVIROLOGY explanation - How to pronounce CRYPTOVIROLOGY? Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. Cryptovirology is a field that studies how to use cryptography to design powerful malicious software. The field was born with the observation that public-key cryptography can be used to break the symmetry between what an antivirus analyst sees regarding malware and what the attacker sees. The antivirus analyst sees a public key contained in the malware whereas the attacker sees the public key contained in the malware as well as the corresponding private key (outside the malware) since the attacker created the key pair for the attack. The public key allows the malware to perform trapdoor one-way operations on the victim's computer that only the attacker can undo. The first attack that was identified by Adam L. Young and Moti Yung in the field is called "cryptoviral extortion" and it was presented at the 1996 IEEE Security & Privacy conference. In this attack a cryptovirus, cryptoworm, or cryptotrojan contains the public key of the attacker and hybrid encrypts the victim's files. The malware prompts the user to send the asymmetric ciphertext to the attacker who will decipher it and return the symmetric decryption key it contains for a fee. The victim needs the symmetric key to get the files back if there are no backups of them. The 1996 IEEE paper of Young and Yung predicted that cryptoviral extortion attackers would one day demand e-money, long before bitcoin even existed. Many years later the media relabeled cryptoviral extortion as ransomware. In 2016 cryptovirology attacks on healthcare providers reached epidemic levels prompting the U.S. Department of Health and Human Services to issue a Fact Sheet on Ransomware and HIPAA. The fact sheet states that when electronic protected health information is encrypted by ransomware a breach has occurred and the attack therefore constitutes a disclosure that is not permitted under HIPAA. The rationale being that an adversary has taken control of the information. This expansion of the term "breach" to account for cryptoviral extortion is monumental since now a "breach" can happen even when sensitive data never leaves the victim organization. California enacted a law that defines the introduction of ransomware into a computer system with the intent of extortion as being against the law. This is SB-1137 that amends Section 523 of the Penal Code. The field also encompasses covert malware attacks in which the attacker securely steals private information such as symmetric keys, private keys, PRNG state, and the victim's data. Examples of such covert attacks are asymmetric backdoors. An asymmetric backdoor is a backdoor (e.g., in a cryptosystem) that can be used only by the attacker, even after it is found. This contrasts with the traditional backdoor that is symmetric, i.e., anyone that finds it can use it. Kleptography, a subfield of cryptovirology, is the study of asymmetric back doors in key generation algorithms, digital signature algorithms, key exchanges, pseudorandom number generators, encryption algorithms, and other cryptographic algorithms. The NIST Dual EC DRBG random bit generator has an asymmetric backdoor in it. The EC-DRBG algorithm utilizes the discrete-log kleptogram from Kleptography which by definition makes the EC-DRBG a cryptotrojan. Like ransomware, the EC-DRBG cryptotrojan contains and uses the attacker's public key to attack the host system. A highly respected cryptographer, Ari Juels, indicated that NSA effectively orchestrated a kleptographic attack on users of the Dual EC DRBG pseudorandom number generation algorithm and that, although security professionals and developers have been testing and implementing kleptographic attacks since 1996, "you would be hard-pressed to find one in actual use until now". Due to public outcry of this cryptovirology attack, NIST rescinded the EC-DRBG algorithm from the NIST SP 800-90 standard.
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What is EPHEMERAL KEY? What does EPHEMERAL KEY mean? EPHEMERAL KEY meaning - EPHEMERAL KEY definition - EPHEMERAL KEY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ A cryptographic key is called ephemeral if it is generated for each execution of a key establishment process. In some cases ephemeral keys are used more than once, within a single session (e.g., in broadcast applications) where the sender generates only one ephemeral key pair per message and the private key is combined separately with each recipient's public key. Contrast with a static key. Private ephemeral key agreement key: Private ephemeral key agreement keys are the private keys of asymmetric key pairs that are used only once to establish one or more keys (e.g., key wrapping keys, data encryption keys, or MAC keys) and, optionally, other keying material (e.g., Initialization Vectors). Public ephemeral key agreement key: Public ephemeral key agreement keys are the public keys of asymmetric key pairs that are used in a single key establishment transaction to establish one or more keys (e.g., key wrapping keys, data encryption keys, or MAC keys) and, optionally, other keying material (e.g., Initialization Vectors).
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What is CRYPTOGRAPHIC SPLITTING? What does CRYPTOGRAPHIC SPLITTING mean? CRYPTOGRAPHIC SPLITTING definition - CRYPTOGRAPHIC SPLITTING explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Cryptographic splitting, also known as cryptographic bit splitting or cryptographic data splitting, is a technique for securing data over a computer network. The technique involves encrypting data, splitting the encrypted data into smaller data units, distributing those smaller units to different storage locations, and then further encrypting the data at its new location. With this process, the data is protected from security breaches, because even if an intruder is able to retrieve and decrypt one data unit, the information would be useless unless it can be combined with decrypted data units from the other locations. The technology was filed for patent consideration in June 2003, and the patent was granted in June 2008. Cryptographic splitting utilizes a combination of different algorithms to provide the data protection. A block of data is first encrypted using the AES-256 government encryption standard. The encrypted bits are then split into different shares and then each share is hashed using the National Security Agency's SHA-256 algorithm. One application of cryptographic splitting is to provide security for cloud computing. The encrypted data subsets can be stored on different clouds, with the information required to restore the data being held on a private cloud for additional security. Security vendor Security First Corp uses this technology for its Secure Parser Extended (SPx) product line. In 2009, technology services company Unisys gave a presentation about using cryptographic splitting with storage area networks. By splitting the data into different parts of the storage area network, this technique provided data redundancy in addition to security. Computer giant IBM has written about using the technology as part of its Cloud Data Encryption Services (ICDES). The technology has also been written about in the context of more effectively using sensitive corporate information, by entrusting different individuals within a company (trustees) with different parts of the information.
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What is CRYPTO CLOUD COMPUTING? What does CRYPTO CLOUD COMPUTING mean? CRYPTO CLOUD COMPUTING meaning - CRYPTO CLOUD COMPUTING definition - CRYPTO CLOUD COMPUTING explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Cloud computing is a combination of IaaS, PaaS, SaaS. To construct a secure cloud computing system, security at infrastructure, service platforms and application software levels have to be studied for a secure cloud computing system. Information encryption is one of effective means to achieve cloud computing information security. Traditionally, information encryption focuses on specified stages and operations, such as data encryption. For cloud computing, a system level design has to be implemented. Crypto cloud computing is a new secure cloud computing architecture. It can provide protection of information security at the system level, and allows users access to shared services conveniently and accurately. Crypto cloud computing protects individual’s connections with the outside world. It can protect the personal privacy without any delay of information exchange. Crypto cloud computing is based on the Quantum Direct Key system. Quantum Direct Key (QDK) is a set of advanced asymmetric offline key mechanism. In this mechanism, all entities get public and private key pair according to their ID. Each entity only holds its own private key, but has a public key generator to generate any public key. In this system, an entity can produce the public key of any other entities offline, no any third-party agency (such as CA) is necessary. Crypto cloud computing based on QDK can avoid network traffic congestion, and other drawbacks using current encryption system. In the crypto cloud computing system, each entity encrypts data using his/her own private key. All elements in the system such as cloud computing infrastructure units, platform, virtualization tools and all involved entities have their own keys. While fulfilling their own functions of information exchange and processing, all these elements will use the public key and private key to perform authentication first. What’s more, events occur in the cloud computing are also assigned a unique key. In this way, crypto cloud system guarantees the security and credibility of information exchange. Current cloud computing structure is developed for data and computing sharing. Security is not priority of system. On the contrary, encryption and security are inherently integrated in the crypto cloud computing based on the QDK. QDK authorized function units are bricks of crypto cloud computing. Besides primary function of data en/decryption, crypto cloud computing also provides many security related functions. For example, all channels sign transmit data using with their own keys, and the receiving terminals can avoid hijacking by verifying signature. What’s more, the exact position of security leakage can be identified determined by analyzing digital signatures of forged data. Based on such capabilities, crypto-related functions can be provided as services in cloud, which is named as ‘Crypto as a service (CAAS)’. Crypto cloud computing is not only the advances in information technology, but also innovation of logical relationship. In crypto cloud computing system, non-system data is not allowed to store and transmit. Private Key and offline public key, play a role of identification and certification in the process of information exchange. In this way, the cloud establishes a relationship of trust with a customer. Data identification depends on the logical relationship of mutual trust or need, and the logical relationship depends on the cloud customer. Crypto cloud computing is a new framework for cyber resource sharing. It protects data security and privacy. Well, in cloud environment, crypto cloud computing guarantees the information security and integrity during whole procedure. Security management of cloud computing can also be performed by authorizing the signatures of every element involved. What’s more, a user can retrieve all related resources using his QDK key. There is no personal privacy under the current cloud framework, as pointed out by Mark Zuckerberg, 'the Age of Privacy Is Over '.However, with the development of crypto cloud computing, we can resolve the conflict between services data sharing and privacy security. It opens up new prospects for the development of information sharing technology.
Views: 145 The Audiopedia

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What is RANDOM ORACLE? What does RANDOM ORACLE mean? RANDOM ORACLE meaning - RANDOM ORACLE definition - RANDOM ORACLE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a random oracle is an oracle (a theoretical black box) that responds to every unique query with a (truly) random response chosen uniformly from its output domain. If a query is repeated it responds the same way every time that query is submitted. Stated differently, a random oracle is a mathematical function chosen uniformly at random, that is, a function mapping each possible query to a (fixed) random response from its output domain. Random oracles as a mathematical abstraction were firstly used in rigorous cryptographic proofs in the 1993 publication by Mihir Bellare and Phillip Rogaway (1993). They are typically used when the cryptographic hash functions in the method cannot be proven to possess the mathematical properties required by the proof. A system that is proven secure when every hash function is replaced by a random oracle is described as being secure in the random oracle model, as opposed to secure in the standard model of cryptography. Random oracles are typically used as an ideal replacement for cryptographic hash functions in schemes where strong randomness assumptions are needed of the hash function's output. Such a proof generally shows that a system or a protocol is secure by showing that an attacker must require impossible behavior from the oracle, or solve some mathematical problem believed hard in order to break it. Not all uses of cryptographic hash functions require random oracles: schemes that require only one or more properties having a definition in the standard model (such as collision resistance, preimage resistance, second preimage resistance, etc.) can often be proven secure in the standard model (e.g., the Cramer–Shoup cryptosystem). Random oracles have long been considered in computational complexity theory, and many schemes have been proven secure in the random oracle model, for example Optimal Asymmetric Encryption Padding, RSA-FDH and Probabilistic Signature Scheme. In 1986, Amos Fiat and Adi Shamir showed a major application of random oracles – the removal of interaction from protocols for the creation of signatures. In 1989, Russell Impagliazzo and Steven Rudich showed the limitation of random oracles – namely that their existence alone is not sufficient for secret-key exchange. In 1993, Mihir Bellare and Phillip Rogaway were the first to advocate their use in cryptographic constructions. In their definition, the random oracle produces a bit-string of infinite length which can be truncated to the length desired. According to the Church–Turing thesis, no function computable by a finite algorithm can implement a true random oracle (which by definition requires an infinite description). In fact, certain artificial signature and encryption schemes are known which are proven secure in the random oracle model, but which are trivially insecure when any real function is substituted for the random oracle. Nonetheless, for any more natural protocol a proof of security in the random oracle model gives very strong evidence of the practical security of the protocol. In general, if a protocol is proven secure, attacks to that protocol must either be outside what was proven, or break one of the assumptions in the proof; for instance if the proof relies on the hardness of integer factorization, to break this assumption one must discover a fast integer factorization algorithm. Instead, to break the random oracle assumption, one must discover some unknown and undesirable property of the actual hash function; for good hash functions where such properties are believed unlikely, the considered protocol can be considered secure.
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What is VISUAL CRYPTOGRAPHY? What does VISUAL CRYPTOGRAPHY mean? VISUAL CRYPTOGRAPHY meaning - VISUAL CRYPTOGRAPHY definition - VISUAL CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Visual cryptography is a cryptographic technique which allows visual information (pictures, text, etc.) to be encrypted in such a way that decryption becomes the job of the person to decrypt via sight reading. One of the best-known techniques has been credited to Moni Naor and Adi Shamir, who developed it in 1994. They demonstrated a visual secret sharing scheme, where an image was broken up into n shares so that only someone with all n shares could decrypt the image, while any n - 1 shares revealed no information about the original image. Each share was printed on a separate transparency, and decryption was performed by overlaying the shares. When all n shares were overlaid, the original image would appear. There are several generalizations of the basic scheme including k-out-of-n visual cryptography. Using a similar idea, transparencies can be used to implement a one-time pad encryption, where one transparency is a shared random pad, and another transparency acts as the ciphertext. Normally, there is an expansion of space requirement in visual cryptography. But if one of the two shares is structured recursively, the efficiency of visual cryptography can be increased to 100%. Some antecedents of visual cryptography are in patents from the 1960s. Other antecedents are in the work on perception and secure communication. Visual cryptography can be used to protect biometric templates in which decryption does not require any complex computations.
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What is OFF-THE-RECORD MESSAGING? What does OFF-THE-RECORD MESSAGING mean? OFF-THE-RECORD MESSAGING meaning - OFF-THE-RECORD MESSAGING definition - OFF-THE-RECORD MESSAGING explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Off-the-Record Messaging (OTR) is a cryptographic protocol that provides encryption for instant messaging conversations. OTR uses a combination of AES symmetric-key algorithm with 128 bits key length, the Diffie–Hellman key exchange with 1536 bits group size, and the SHA-1 hash function. In addition to authentication and encryption, OTR provides forward secrecy and malleable encryption. The primary motivation behind the protocol was providing deniable authentication for the conversation participants while keeping conversations confidential, like a private conversation in real life, or off the record in journalism sourcing. This is in contrast with cryptography tools that produce output which can be later used as a verifiable record of the communication event and the identities of the participants. The initial introductory paper was named "Off-the-Record Communication, or, Why Not To Use PGP". The OTR protocol was designed by cryptographers Ian Goldberg and Nikita Borisov and released on 26 October 2004. They provide a client library to facilitate support for instant messaging client developers who want to implement the protocol. A Pidgin and Kopete plugin exists that allows OTR to be used over any IM protocol supported by Pidgin or Kopete, offering an auto-detection feature that starts the OTR session with the buddies that have it enabled, without interfering with regular, unencrypted conversations. In addition to providing encryption and authentication — features also provided by typical public-key cryptography suites, such as PGP, GnuPG, and X.509 (S/MIME) — OTR also offers some less common features: Forward secrecy: Messages are only encrypted with temporary per-message AES keys, negotiated using the Diffie–Hellman key exchange protocol. The compromise of any long-lived cryptographic keys does not compromise any previous conversations, even if an attacker is in possession of ciphertexts. Deniable authentication: Messages in a conversation do not have digital signatures, and after a conversation is complete, anyone is able to forge a message to appear to have come from one of the participants in the conversation, assuring that it is impossible to prove that a specific message came from a specific person. Within the conversation the recipient can be sure that a message is coming from the person they have identified. As of OTR 3.1, the protocol supports mutual authentication of users using a shared secret through the socialist millionaire protocol. This feature makes it possible for users to verify the identity of the remote party and avoid a man-in-the-middle attack without the inconvenience of manually comparing public key fingerprints through an outside channel. Due to limitations of the protocol, OTR does not support multi-user group chat as of 2009 but it may be implemented in the future. As of version 3 of the protocol specification, an extra symmetric key is derived during authenticated key exchanges that can be used for secure communication (e.g., encrypted file transfers) over a different channel. Support for encrypted audio or video is not planned. (SRTP with ZRTP exists for that purpose.) A project to produce a protocol for multi-party off-the-record messaging (mpOTR) has been organized by Cryptocat, eQualitie, and other contributors including Ian Goldberg. Since OTR protocol v3 (libotr 4.0.0) the plugin supports multiple OTR conversations with the same buddy who is logged in at multiple locations.
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What is PIGGY BANK CRYPTOGRAPHY? What does PIGGY BANK CRYPTOGRAPHY mean? PIGGY BANK CRYPTOGRAPHY meaning - PIGGY BANK CRYPTOGRAPHY definition - PIGGY BANK CRYPTOGRAPHY explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Piggy bank cryptography is a digital emulation of a piggy bank. It uses an encrypted message as a carrier into which valuable secrets can be inserted and later recovered by the person who issued the message. A typical protocol works as follows: Bob, who wishes to obtain secret information from Alice, uses public key cryptography to encrypt some random data with his own public key. He sends the result to Alice. Alice creates a single-use key pair. She injects both her secret and her new decryption key into Bob's message. She then writes a signed note that describes what she has injected. She encrypts the note with her new encryption key, and sends the modified message and note to Bob. Bob decrypts the modified message to obtain both the secret and Alice's decryption key. He uses her decryption key to read the note and verify that Alice sent the secret. In this scheme, Bob does not necessarily require a public key from Alice, although he does require her to sign her note in such a way that he can verify her authorship. Piggy bank cryptography has been proposed for authenticating parties to detect man-in-the-middle attack. The piggy bank paradigm can be used to implement asymmetric as well as double-lock cryptography.
Views: 28 The Audiopedia

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What is CLIENT-SIDE ENCRYPTION? What does CLIENT-SIDE ENCRYPTION mean? CLIENT-SIDE ENCRYPTION meaning - CLIENT-SIDE ENCRYPTION definition - CLIENT-SIDE ENCRYPTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Client-side encryption is the cryptographic technique of encrypting data on the sender's side, before it is transmitted to a server such as a cloud storage service. Client-side encryption features an encryption key that is not available to the service provider, making it difficult or impossible for service providers to decrypt hosted data. Client-side encryption allows for the creation of zero-knowledge applications whose providers cannot access the data its users have stored, thus offering a high level of privacy. Client-side encryption is widely recognized as an exceptionally robust data security strategy. By eliminating the potential for data to be viewed by service providers (or third parties that compel service providers to deliver access to data), client-side encryption ensures that data and files that are stored in the cloud can only be viewed on the client side of the exchange. This prevents data loss and the unauthorized disclosure of private or personal files, providing increased peace of mind for both personal and business users. Current academic scholarship as well as recommendations by industry professionals provide much support for developers to include client-side encryption to protect the confidentiality and integrity of information. Examples of cloud storage services that provide client-side encryption are Tresorit, MEGA and SpiderOak. As of February 2016, neither Apple iCloud, Google Drive, or Dropbox provide client-side encryption.
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What is WEB OF TRUST? What does WEB OF TRUST mean? WEB OF TRUST meaning - WEB OF TRUST definition - WEB OF TRUST explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-compatible systems to establish the authenticity of the binding between a public key and its owner. Its decentralized trust model is an alternative to the centralized trust model of a public key infrastructure (PKI), which relies exclusively on a certificate authority (or a hierarchy of such). As with computer networks, there are many independent webs of trust, and any user (through their identity certificate) can be a part of, and a link between, multiple webs. The web of trust concept was first put forth by PGP creator Phil Zimmermann in 1992 in the manual for PGP version 2.0: As time goes on, you will accumulate keys from other people that you may want to designate as trusted introducers. Everyone else will each choose their own trusted introducers. And everyone will gradually accumulate and distribute with their key a collection of certifying signatures from other people, with the expectation that anyone receiving it will trust at least one or two of the signatures. This will cause the emergence of a decentralized fault-tolerant web of confidence for all public keys. All OpenPGP-compliant implementations include a certificate vetting scheme to assist with this; its operation has been termed a web of trust. OpenPGP identity certificates (which include public key(s) and owner information) can be digitally signed by other users who, by that act, endorse the association of that public key with the person or entity listed in the certificate. This is commonly done at key signing parties. OpenPGP-compliant implementations also include a vote counting scheme which can be used to determine which public key – owner association a user will trust while using PGP. For instance, if three partially trusted endorsers have vouched for a certificate (and so its included public key – owner binding), OR if one fully trusted endorser has done so, the association between owner and public key in that certificate will be trusted to be correct. The parameters are user-adjustable (e.g., no partials at all, or perhaps 6 partials) and can be completely bypassed if desired. The scheme is flexible, unlike most public key infrastructure designs, and leaves trust decision(s) in the hands of individual users. It is not perfect and requires both caution and intelligent supervision by users. Essentially all PKI designs are less flexible and require users to follow the trust endorsement of the PKI generated, certificate authority (CA)-signed, certificates. There are two keys: a public key which is shared openly and a private key that only the user knows. The user's private key will decrypt any information encrypted with the user's public key. In the web of trust, each user has a ring with a group of people's public keys. Users encrypt their information with the recipient's public key, and only the recipient's private key will decrypt it. Each user then digitally signs the information with their private key, so when they verify it with their own public key, they can confirm that it is the person in question. Doing this will ensure that the information came from the specific user and has not been tampered with, and only the intended recipient can read the information (because only they know their private key).
Views: 1949 The Audiopedia

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What is INTERPOLATION ATTACK? What does INTERPOLATION ATTACK mean? INTERPOLATION ATTACK meaning - INTERPOLATION ATTACK definition - INTERPOLATION ATTACK explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, an interpolation attack is a type of cryptanalytic attack against block ciphers. After the two attacks, differential cryptanalysis and linear cryptanalysis, were presented on block ciphers, some new block ciphers were introduced, which were proven secure against differential and linear attacks. Among these there were some iterated block ciphers such as the KN-Cipher and the SHARK cipher. However, Thomas Jakobsen and Lars Knudsen showed in the late 90's that these ciphers were easy to break by introducing a new attack called the interpolation attack. In the attack, an algebraic function is used to represent an S-box. This may be a simple quadratic, or a polynomial or rational function over a Galois field. Its coefficients can be determined by standard Lagrange interpolation techniques, using known plaintexts as data points. Alternatively, chosen plaintexts can be used to simplify the equations and optimize the attack. In its simplest version an interpolation attack expresses the ciphertext as a polynomial of the plaintext. If the polynomial has a relative low number of unknown coefficients, then with a collection of plaintext/ciphertext (p/c) pairs, the polynomial can be reconstructed. With the polynomial reconstructed the attacker then has a representation of the encryption, without exact knowledge of the secret key. The interpolation attack can also be used to recover the secret key. It is easiest to describe the method with an example.
Views: 97 The Audiopedia

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What is BLISS SIGNATURE SCHEME? What does BLISS SIGNATURE SCHEME mean? BLISS SIGNATURE SCHEME meaning - BLISS SIGNATURE SCHEME definition - BLISS SIGNATURE SCHEME explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ BLISS (short for Bimodal Lattice Signature Scheme) is a digital signature scheme proposed by Léo Ducas, Alain Durmus, Tancrede Lepoint and Vadim Lyubashevsky in their 2013 paper "Lattice Signature and Bimodal Gaussians". In cryptography, digital signature ensures that a message is authentically from a specific person who has the private key to create such signature, and such signature can be verified using the corresponding public key. Current signature schemes relies on one of integer factorization, discrete logarithm, and elliptic curve discrete logarithm problem, which can be effectively attacked by a quantum computer. BLISS on the other hand, is a post-quantum algorithm, and is meant to resist quantum computer attacks. Compared to other post-quantum schemes, BLISS claims to offer better computational efficiency, smaller signature size, and higher security. A presentation given at NIST has therefore anticipated that BLISS be further refined and become a potential candidate for standardization.
Views: 71 The Audiopedia

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What is HARDWARE OBFUSCATION? What does HARDWARE OBFUSCATION mean? HARDWARE OBFUSCATION meaning - HARDWARE OBFUSCATION definition - HARDWARE OBFUSCATION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Hardware obfuscation is a technique by which the description or the structure of electronic hardware is modified to intentionally conceal its functionality, which makes it significantly more difficult to reverse-engineer. In essence, it is different from digital watermarking (where the ownership is concealed in the digital content itself), or from hardware intellectual property (IP) watermarking where the ownership information is embedded and concealed in the description of a circuit. It is also different from cryptography-based hardware IP protection techniques common in the design flow of Field Programmable Gate Array. The importance of hardware watermarking has increased in the recent years due to widespread adoption of hardware IP based design practices for modern integrated circuits (ICs) such as system on chips (SoCs). Major security issues associated with hardware IPs include: (a) hardware intellectual property infringement during SoC design; (b) reverse engineering the manufactured ICs or the IC design database (in fabrication facilities) to produce counterfeit or clone ICs; and (c) malicious modifications of an IP through the insertion of hardware Trojan to cause in-field functional failure. Hardware obfuscation aims at minimizing these threats at IP or chip level by making it difficult for an adversary to comprehend the actual functionality of a design. Hardware obfuscation techniques can be classified into two main categories: (a) the "passive" techniques, which do not directly affect the functionality of the electronic system, and (b) the "active" techniques, which directly alter the functionality of the system. Often the active hardware obfuscation techniques are "key-based", such that normal functionality of the obfuscated design can only be enabled by the successful application of a single pre-determined key or a sequence of secret keys at the input; otherwise the circuit operates in a mode, which exhibits incorrect functionality. This can be done by embedding a well-hidden finite state machine (FSM) in the circuit to control the functional modes based on application of key. The technique of key-based, active hardware obfuscation is similar in principle to private-key cryptographic approaches for information protection, since the "key sequence" for the obfuscated design plays a similar role as the cryptographic key. The technique can be applied at different levels of hardware description, namely gate-level or register transfer level (RTL) design and hence can be used to protect soft, firm and hard IP cores. Obfuscation can also help to effectively hide security features in an IC and thus enable protection of ICs from counterfeiting and cloning in fabrication facilities. In contrast, the passive techniques modify the circuit description in a soft form (e.g. syntactic changes), such that it becomes difficult for a human reader to understand the functionality of the circuit. These approaches typically employ either string-substitution (including variable name change, comment removal, etc.), or structural change in the hardware description language (HDL) description of a circuit (including loop unrolling, register renaming, etc.). A major shortcoming of the passive approaches is that they do not modify the black box functionality of a circuit, and hence cannot prevent potential usage of an IP as black-box in a design. Moreover, the actual strength of such passive obfuscation is debatable, since, in general, black-box obfuscation does not exist, at least for software programs computing certain mathematical functions. Hardware watermarking can be used in conjunction with hardware obfuscation. In an obfuscated design, watermarking can be effective in providing a second line of defense against unlicensed copying efforts.
Views: 119 The Audiopedia

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What is KEY RING FILE? What does KEY RING FILE mean? KEY RING FILE meaning - KEY RING FILE definition - KEY RING FILE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. A key ring is a file which contains multiple public keys of certificate authority (CA). A key ring is a file which is necessary for Secure Sockets Layer (SSL) connection over the web. It is securely stored on the server which hosts the website. It contains the public/private key pair for the particular website. It also contains the public/private key pairs from various certificate authorities and the trusted root certificate for the various certification authorities. An entity or website administrator has to send a certificate signing request (CSR) to the CA. The CA then returns a signed certificate to the entity. This certificate received from the CA has to be stored in the key ring.
Views: 59 The Audiopedia

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What is INTERLOCK PROTOCOL? What does INTERLOCK PROTOCOL mean? INTERLOCK PROTOCOL meaning - INTERLOCK PROTOCOL definition - INTERLOCK PROTOCOL explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ The interlock protocol, as described by Ron Rivest and Adi Shamir, was designed to frustrate eavesdropper attack against two parties that use an anonymous key exchange protocol to secure their conversation. A further paper proposed using it as an authentication protocol, which was subsequently broken. Most cryptographic protocols rely on the prior establishment of secret or public keys or passwords. However, the Diffie-Hellman key exchange protocol introduced the concept of two parties establishing a secure channel (that is, with at least some desirable security properties) without any such prior agreement. Unauthenticated Diffie-Hellman, as an anonymous key agreement protocol, has long been known to be subject to man in the middle attack. However, the dream of a "zipless" mutually authenticated secure channel remained. The Interlock Protocol was described as a method to expose a middle-man who might try to compromise two parties that use anonymous key agreement to secure their conversation. The Interlock protocol works roughly as follows: Alice encrypts her message with Bob's key, then sends half her encrypted message to Bob. Bob encrypts his message with Alice's key and sends half of his encrypted message to Alice. Alice then sends the other half of her message to Bob, who sends the other half of his. The strength of the protocol lies in the fact that half of an encrypted message cannot be decrypted. Thus, if Mallory begins her attack and intercepts Bob and Alice's keys, Mallory will be unable to decrypt Alice's half-message (encrypted using her key) and re-encrypt it using Bob's key. She must wait until both halves of the message have been received to read it, and can only succeed in duping one of the parties if she composes a completely new message.
Views: 343 The Audiopedia

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On today's episode of The Cryptoverse: Its national railway service may have already jumped on the bitcoin bandwagon, but Switzerland is taking a slower approach as it looks to regulate digital currencies and fintech. Please Support The Cryptoverse Podcast by visiting the Cryptoversity Store: https://www.cryptoversity.com/store Please Support The Cryptoverse With A Bitcoin Donation: 1Lak8zkQbUB5FgDD6ci6M82oTVBveuBxBT Subscribe to the podcast here: https://www.cryptoversity.com/podcast/ Today's episode is sponsored by TunnelBear, the simple VPN app that makes it easy to browse the web privately and enjoy a more open and secure Internet experience. [Try it for free here](http://click.tunnelbear.com/SH8n) Disclaimer: I personally use TunnelBear every day and if you decide to upgrade to a paid plan using my link it generates commission to help support the show. Sources: [The Original Article on CoinDesk](http://www.coindesk.com/switzerland-bitcoin-regulation/) [List ob LBRY Team Members](https://lbry.io/team) [Wikipedia Article on The Two Generals Problem](https://en.wikipedia.org/wiki/Two_Generals%27_Problem) [Dictionary Definition of Regulate](http://www.dictionary.com/browse/regulate?s=t) Produced by Cryptoversity.com the online school for learning about Bitcoin, crypto-currencies and blockchains. https://www.cryptoversity.com/ Please upvote to support the show, I really appreciate it. https://steemit.com/crypto-news/@marketingmonk/swiss-lawmakers-take-steps-toward-bitcoin-regulation-the-cryptoverse-136
Views: 1096 The Cryptoverse

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