# 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:
 bitcoin× 20 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. elgamal-signature× 20 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. man-in-the-middle× 20 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… side-channel-attacks× 20 attacks using information leaked by implementations of cryptographic algorithms to obtain information about keys or (plaintext) data, instead of (or additional to) using cryptographic weaknesses. statistical-test× 20 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… proof-of-work× 19 based on a mathematical problem that is moderate hard to solve but easy to verify. performance× 19 Performance defines the abilities of a cipher in terms of processing throughput on various platforms, including its memory requirements. keccak× 19 a cryptographic hash function designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche. multiple-encryption× 19 Multiple encryption means encrypting a message two or more times using either the same, or a different algorithm. nist× 19 The National Institute of Standards and Technology (NIST) is a U.S. federal agency that works with industry to develop and apply technology, measurements, and standards. blowfish× 19 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… anonymity× 19 Anonymity describes the state of being unknown or unacknowledged. blind-signature× 18 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… compression× 18 the reduction in size of data without losing information. commitments× 18 a protocol where one party commits themselves to a secret value without revealing it. At a later point, the value can be revealed. ed25519× 18 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. format-preserving× 18 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. paillier× 18 A public-key cryptosystem invented by Pascal Paillier in 1999. pseudo-random-permutation× 17 a function that cannot be distinguished (with practical effort) from a permutation selected at random with uniform probability from the family of all permutations … semantic-security× 17 produces ciphertext that, by itself, does not reveal information about the original message besides its length nonce× 17 an arbitrary number or string used only once within the context of a specific cryptographic scheme. Nonces are used e.g. in authentication protocols to prevent replay attacks, as well as … hkdf× 17 a key derivation function specified in RFC5869. identity-based-encryption× 17 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… backdoors× 17 A backdoor in a cryptosystem or algorithm allows someone to obtain access to the decrypted data, without the need for the key/password that was used to encrypt the data. vigenere× 17 a classical cipher that shifts each plaintext character by the value of the key at the same position modulo the key-length. 2nd-preimage-resistance× 16 Difficulty of finding another input string that hashes to the same value as a given string hill-cipher× 16 a historic polygraphic substitution cipher invented by Lester S. Hill in 1929. notation× 16 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. nsa× 16 the central producer and manager of signals intelligence for the United States Government. pen-and-paper× 16 The term "pen and paper" can practically be interpreted as "using no tools like electronic devices", since it targets cryptographic functions, schemes, and procedures which can be handled by humans wh… oblivious-transfer× 15 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… mceliece× 15 an asymmetric encryption algorithm and is a candidate for "post-quantum cryptography", as it is immune to attacks using Shor's algorithm and — more generally — measuring coset… meet-in-the-middle-attack× 15 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… hash-tree× 15 a method of hierarchically hashing data. They allow efficient parallel hashing and updates and the possibility of verifying partial data. sha-512× 15 part of the SHA-2 family of hash functions with a 512-bit output and a 256-bit security level. srp-6× 15 Secure Remote Password protocol version 6.