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.
Complexity describes - in simple words - how hard (complex) it is to reach a specific goal; and under which conditions. In cryptography, this mostly ends up in using the complexity theory to analyze t…
Questions about formal definitions of "security" for various cryptographic schemes (e.g. perfect secrecy, semantic security, ciphertext indistinguishability, etc.)
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…
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…
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…
The attacker knows at least one sample of both the plain text and the cipher text.
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.
the detailed analysis of the security of an abstract or concrete cryptographic protocol.
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…
a protocol where one party commits themselves to a secret value without revealing it. At a later point, the value can be revealed.
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 …
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.
A way, esp. one of several possible variations, in which a set or number of things can be ordered or arranged.
an encryption algorithm which works by replacing plaintext units with corresponding ciphertext units, following some rule depending on the key.
Difficulty of finding an input string that hashes to a given value
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.
Encryption using a key derived from a password or passphrase entered by the user.
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 cryptographic hash function standardized by NIST as a new alternative to the SHA-2 hash function family.
A public-key cryptosystem invented by Pascal Paillier in 1999.
the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as cipherte…
Deprecated tag, see tag info. Advanced Encryption Standard Galois/Counter Mode, better known as AES-GCM is a mode of operation for symmetric key cryptographic block ciphers that has been widely ado…
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.
In a cryptographic sense, integrity means unimpaired and complete.
a family of stream ciphers proposed by Daniel J. Bernstein, as an evolution of Salsa20 with (conjecturally) improved resistance to cryptanalysis.
Linear Feedback Shift Register, a pseudorandom bit generator which can be efficiently implemented in hardware.
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).
Cryptographic hardware enables the handling of cryptographic tasks and/or problems using hardware instead of software solutions.
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 form of cryptanalysis which studies cryptographic algorithms by observing how differences in input affect differences in output.
a structure that has been used to create a number of different block ciphers (e.g., DES, Blowfish, Twofish, RC6).
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.
thought to be difficult to solve for all cases in polynomial time