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.
the study of the properties and construction of numbers, particularly integers. Prime numbers are of particular interest to number theorists and consequently cryptographers as they ar…
Questions about formal definitions of "security" for various cryptographic schemes (e.g. perfect secrecy, semantic security, ciphertext indistinguishability, etc.)
Irreversibly converting user-selected passwords into authentication tokens that can be safely stored e.g. in a user database. Typically done with a salted password-based key derivation function (PBKDF…
the detailed analysis of the security of an abstract or concrete cryptographic protocol.
The attacker knows at least one sample of both the plain text and the cipher text.
unique (usually random) data passed into a hash function for password storage to avoid the possible usage of rainbow tables or similar attacks. Salt will not help against dictionary or brute f…
a digital currency powered by cryptography. This tag is applicable only to Q&As about the cryptographic mechanisms used by a currency, not for questions about economy, usage, or ac…
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…
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.
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 …
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.
The process of encrypting individual files on a storage medium and permitting access to the encrypted data only after proper authentication is provided.
an encryption algorithm which works by replacing plaintext units with corresponding ciphertext units, following some rule depending on the key.
Encryption using a key derived from a password or passphrase entered by the user.
A way, esp. one of several possible variations, in which a set or number of things can be ordered or arranged.
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 …
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.
a protocol where one party commits themselves to a secret value without revealing it. At a later point, the value can be revealed.
a function that cannot be distinguished (with practical effort) from a permutation selected at random with uniform probability from the family of all permutations …
a mode of operation for a block cipher, with the characteristic that each possible block of plaintext has a defined corresponding ciphertext value and vice versa.
Difficulty of finding an input string that hashes to a given value
a cryptographic hash function standardized by NIST as a new alternative to the SHA-2 hash function family.
In a cryptographic sense, integrity means unimpaired and complete.
Linear Feedback Shift Register, a pseudorandom bit generator which can be efficiently implemented in hardware.
Cryptographic hardware enables the handling of cryptographic tasks and/or problems using hardware instead of software solutions.
a family of cryptographic hash functions designed by the NSA and published by NIST in 2001. The family includes various output lengths (224, 256, 384, and 512 bits).
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…
A block cypher encryption algorithm built from applying three iterations of the original DES algorithm.
a structure that has been used to create a number of different block ciphers (e.g., DES, Blowfish, Twofish, RC6).
a fast and simple stream cipher used correctly in SSL and incorrectly in WEP.
Performance defines the abilities of a cipher in terms of processing throughput on various platforms, including its memory requirements.
Quantum cryptography describes the use of quantum mechanical effects to perform cryptographic tasks. This is not to be confused with quantum computing or cryptanalysis techniques such as Shor's algori…
a classical cipher that shifts each plaintext character by the value of the key at the same position modulo the key-length.
part of the SHA-2 family of hash functions with a 512-bit output and a 256-bit security level.