# 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:
 random-oracle-model× 34 A model used in cryptographic security proofs, in which concrete primitives such as hash functions are replaced with a "random oracle": a hypothetical black box that maps its inputs to truly random ou… rijndael× 34 a family of symmetric block-ciphers with block and keys sizes of 128, 160, 192, 224, or 256 bits. ntru× 33 an encryption algorithm which is based on the shortest vector problem in a lattice. man-in-the-middle× 33 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… scrypt× 33 A slow and memory-intensive hash function designed for passwords srp× 32 a modern cryptographic protocol for password authenticated key exchange (PAKE). It provides some desireable properties, like a passive eavesdropper being unabl… multiple-encryption× 32 Multiple encryption means encrypting a message two or more times using either the same, or a different algorithm. pseudo-random-permutation× 32 a function that cannot be distinguished (with practical effort) from a permutation selected at random with uniform probability from the family of all permutations … commitments× 32 a protocol where one party commits themselves to a secret value without revealing it. At a later point, the value can be revealed. sha-3× 31 a cryptographic hash function standardized by NIST as a new alternative to the SHA-2 hash function family. timing-attacks× 30 side channel attack based on the different speed at which certain operations are executed. database× 30 A structured set of data held in a computer, esp. one that is accessible in various ways. elgamal-signature× 30 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. perfect-secrecy× 30 Confidentiality in a very strong sense. Ciphers reaching perfect-secrecy can't be broken to disclose informations over the plaintext from the ciphertext, even with unlimited computing power. The most … lattice-crypto× 29 blowfish× 29 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… statistical-test× 29 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… sha-512× 28 part of the SHA-2 family of hash functions with a 512-bit output and a 256-bit security level. anonymity× 28 Anonymity describes the state of being unknown or unacknowledged. identity-based-encryption× 27 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… notation× 27 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. proof-of-work× 26 based on a mathematical problem that is moderate hard to solve but easy to verify. steganography× 26 the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message. While cryptography prot… ssh× 25 an authentication protocol (described in RFC 4252) for securely getting access to a remote computer. semantic-security× 25 produces ciphertext that, by itself, does not reveal information about the original message besides its length one-time-password× 25 a password that is valid for only one session or transaction. meet-in-the-middle-attack× 25 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… keccak× 25 a cryptographic hash function designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche. 2nd-preimage-resistance× 25 Difficulty of finding another input string that hashes to the same value as a given string blocksize× 25 a sequence of bytes or bits, having a fixed length (the block-size). blind-signature× 25 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… forward-secrecy× 25 A security property wherein past messages are protected against future compromise of the master keys. history× 24 History of cryptography and cryptanalysis. Questions that wish to ask about the history of cryptography should use this tag; if you're asking about historical ciphers you may also wish to use the clas… hkdf× 24 a key derivation function specified in RFC5869. differential-analysis× 24 a form of cryptanalysis which studies cryptographic algorithms by observing how differences in input affect differences on output. bitcoin× 24 a digital peer-to-peer currency with no central authority. It was created in 2009 by Satoshi Nakamoto. Transactions are managed entirely by the network.