# Tags

A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

 Type to find tags:
 vigenere× 28 a classical cipher that shifts each plaintext character by the value of the key at the same position modulo the key-length. sha-3× 27 a cryptographic hash function standardized by NIST as a new alternative to the SHA-2 hash function family. standards× 27 Questions about official cryptographic standards and their implementation. statistical-test× 27 used to estimate the likelihood of a hypothesis given a set of data. In cryptanalysis, statistical testing is commonly used to detect non-randomness in the data, e.g. distinguis… chosen-ciphertext-attack× 27 an attack model for cryptanalysis in which the cryptanalyst gathers information, at least in part, by choosing a ciphertext and obtaining its decryption under an un… format-preserving× 25 Format-preserving encryption (FPE) refers to encrypting in such a way that the output has the same length as the input, or otherwise has the same format or structure as the input. multiple-encryption× 25 Multiple encryption means encrypting a message two or more times using either the same, or a different algorithm. one-time-password× 25 a password that is valid for only one session or transaction. performance× 24 Performance defines the abilities of a cipher in terms of processing throughput on various platforms, including its memory requirements. proof-of-work× 24 based on a mathematical problem that is moderate hard to solve but easy to verify. man-in-the-middle× 24 an active attack where the attacker is able to interpose himself between the sender and receiver. The attacker may monitor and/or modify some or all of the messag… identity-based-encryption× 24 In identity-based encryption (IBE) the public key of a user $A$ is some identity string $ID_A$, e.g., an email address. To encrypt a message for this user there is no need to retrieve an authentic cop… keccak× 24 a cryptographic hash function designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche. elgamal-signature× 24 A digital signature scheme based on the discrete logarithm problem, published by Taher ElGamal in 1984. Not to be confused with the ElGamal encryption system. ed25519× 24 an algorithm for producing digital signatures. The algorithm is based on Edwards curves introduced by Bernstein et al. (2007) and named after mathematician Harold M. Edwards. commitments× 24 a protocol where one party commits themselves to a secret value without revealing it. At a later point, the value can be revealed. anonymity× 24 Anonymity describes the state of being unknown or unacknowledged. blowfish× 23 an encryption algorithm that can be used as a replacement for the DES or IDEA algorithms. Blowfish was designed in 1993 by Bruce Schneier as an alternative to existing encryption algorithm… pseudo-random-permutation× 23 a function that cannot be distinguished (with practical effort) from a permutation selected at random with uniform probability from the family of all permutations … quantum-cryptography× 23 Quantum cryptography describes the use of quantum mechanical effects to perform cryptographic tasks or to break cryptographic systems. blind-signature× 22 In a blind signature scheme, the signer does not know what he is signing. This is an important building block of anonymous voting or digital cash schemes, because it allows an authority to control the… blocksize× 21 a sequence of bytes or bits, having a fixed length (the block-size). historic× 21 for questions about cryptographic algorithms which were invented (and used) before the computer age. oblivious-transfer× 21 Oblivious transfer refers to a cryptographic protocol in which a sender possesses a set of data and a receiver queries the sender for a particular member of that set in such a way that the sender does… ntru× 21 an encryption algorithm which is based on the shortest vector problem in a lattice. notation× 20 Questions on the meaning, history, and usage of symbols and notation in cryptography. Please remember to mention where (book, paper, webpage, etc.) you encountered any notation you are asking about. meet-in-the-middle-attack× 20 an optimized brute-force attack that significantly reduces the number of keys the attacker needs to try by utilizing a time-space trade-off. Work is done from the begi… timing-attacks× 20 side channel attack based on the different speed at which certain operations are executed. sha-512× 20 part of the SHA-2 family of hash functions with a 512-bit output and a 256-bit security level. semantic-security× 19 produces ciphertext that, by itself, does not reveal information about the original message besides its length ssh× 19 an authentication protocol (described in RFC 4252) for securely getting access to a remote computer. javascript× 19 a dynamic, object-oriented, prototype-based, weakly typed language commonly used for scripting in web browsers. Despite the name, it is unrelated to the Java programming language and sha… hkdf× 19 a key derivation function specified in RFC5869. hill-cipher× 19 a historic polygraphic substitution cipher invented by Lester S. Hill in 1929. forward-secrecy× 19 A security property wherein past messages are protected against future compromise of the master keys. differential-analysis× 19 a form of cryptanalysis which studies cryptographic algorithms by observing how differences in input affect differences on output.