# Category: Cryptographic algorithms

Double Ratchet Algorithm
In cryptography, the Double Ratchet Algorithm (previously referred to as the Axolotl Ratchet) is a key management algorithm that was developed by and Moxie Marlinspike in 2013. It can be used as part
BB84
BB84 is a quantum key distribution scheme developed by Charles Bennett and Gilles Brassard in 1984. It is the first quantum cryptography protocol. The protocol is provably secure, relying on two condi
Generation of primes
In computational number theory, a variety of algorithms make it possible to generate prime numbers efficiently. These are used in various applications, for example hashing, public-key cryptography, an
Time-based one-time password (TOTP) is a computer algorithm that generates a one-time password (OTP) that uses the current time as a source of uniqueness. As an extension of the HMAC-based one-time pa
Six-state protocol
The six-state protocol (SSP) is the quantum cryptography protocol that is the version of BB84 that uses a six-state polarization scheme on three orthogonal bases.
Geometric cryptography
Geometric cryptography is an area of cryptology where messages and ciphertexts are represented by geometric quantities such as angles or intervals and where computations are performed by ruler and com
Key wrap
In cryptography, key wrap constructions are a class of symmetric encryption algorithms designed to encapsulate (encrypt) cryptographic key material. The Key Wrap algorithms are intended for applicatio
Scrypt
In cryptography, scrypt (pronounced "ess crypt") is a password-based key derivation function created by Colin Percival in March 2009, originally for the Tarsnap online backup service. The algorithm wa
Kunerth's algorithm
Kunerth's algorithm is an algorithm to determine the modular square root of a number.The algorithm does not require the factorization of the modulus, and only has one modular operation that is often e
PEGASUS
PEGASIS is an encryption algorithm used for satellite telemetry, command link and mission data transfers. According to budget item justification document for FY 2004–2005, this cryptographic algorithm
Crypto++
Crypto++ (also known as CryptoPP, libcrypto++, and libcryptopp) is a free and open-source C++ class library of cryptographic algorithms and schemes written by Wei Dai. Crypto++ has been widely used in
Ciphertext stealing
In cryptography, ciphertext stealing (CTS) is a general method of using a block cipher mode of operation that allows for processing of messages that are not evenly divisible into blocks without result
Block cipher mode of operation
In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity. A block cipher by itself is only sui
Secret sharing using the Chinese remainder theorem
Secret sharing consists of recovering a secret S from a set of shares, each containing partial information about the secret. The Chinese remainder theorem (CRT) states that for a given system of simul
Equihash
Equihash is a memory-hard Proof-of-Work algorithm introduced by the University of Luxembourg's Interdisciplinary Centre for Security, Reliability and Trust (SnT) at the 2016 Network and Distributed Sy
CDMF
In cryptography, CDMF (Commercial Data Masking Facility) is an algorithm developed at IBM in 1992 to reduce the security strength of the 56-bit DES cipher to that of 40-bit encryption, at the time a r
Common Scrambling Algorithm
The Common Scrambling Algorithm (CSA) is the encryption algorithm used in the DVB digital television broadcasting for encrypting video streams. CSA was specified by ETSI and adopted by the DVB consort
Cryptographic agility
Cryptographic agility (also referred to as crypto-agility) is a practice paradigm in designing information security protocols and standards in a way so that they can support multiple cryptographic pri
Feedback with Carry Shift Registers
In sequence design, a Feedback with Carry Shift Register (or FCSR) is the arithmetic or with carry analog of a linear-feedback shift register (LFSR). If is an integer, then an N-ary FCSR of length is
NSA product types
The U.S. National Security Agency (NSA) used to rank cryptographic products or algorithms by a certification called product types. Product types were defined in the National Information Assurance Glos
Residual block termination
In cryptography, residual block termination is a variation of cipher block chaining mode (CBC) that does not require any padding. It does this by effectively changing to cipher feedback mode for one b
Ring learning with errors key exchange
In cryptography, a public key exchange algorithm is a cryptographic algorithm which allows two parties to create and share a secret key, which they can use to encrypt messages between themselves. The
Dynamic encryption
Dynamic Encryption is a cryptographic principle that enables two parties to change the encryption algorithm for every transaction.
RC algorithm
The RC algorithms are a set of symmetric-key encryption algorithms invented by Ron Rivest. The "RC" may stand for either Rivest's cipher or, more informally, Ron's code. Despite the similarity in thei
Modular exponentiation
Modular exponentiation is exponentiation performed over a modulus. It is useful in computer science, especially in the field of public-key cryptography, where it is used in both Diffie-Hellman Key Exc
LSH (hash function)
LSH is a cryptographic hash function designed in 2014 by South Korea to provide integrity in general-purpose software environments such as PCs and smart devices. LSH is one of the cryptographic algori
MOSQUITO
In cryptography, MOSQUITO was a stream cipher algorithm designed by Joan Daemen and Paris Kitsos. It was submitted to the eSTREAM Project of the eCRYPT network. After the initial design was broken by
Supersingular isogeny key exchange
Supersingular isogeny Diffie–Hellman key exchange (SIDH or SIKE) is an insecure proposal for a post-quantum cryptographic algorithm to establish a secret key between two parties over an untrusted comm
Fuzzy extractor
Fuzzy extractors are a method that allows biometric data to be used as inputs to standard cryptographic techniques, to enhance computer security. "Fuzzy", in this context, refers to the fact that the
Montgomery modular multiplication
In modular arithmetic computation, Montgomery modular multiplication, more commonly referred to as Montgomery multiplication, is a method for performing fast modular multiplication. It was introduced
Randomness merger
In extractor theory, a randomness merger is a function which extracts randomness out of a set of random variables, provided that at least one of them is uniformly random. Its name stems from the fact
HMAC-based one-time password (HOTP) is a one-time password (OTP) algorithm based on HMAC. It is a cornerstone of the Initiative for Open Authentication (OATH). HOTP was published as an informational I
Kochanski multiplication
Kochanski multiplication is an algorithm that allows modular arithmetic (multiplication or operations based on it, such as exponentiation) to be performed efficiently when the modulus is large (typica
Industrial-grade primes (the term is apparently due to Henri Cohen) are integers for which primality has not been certified (i.e. rigorously proven), but they have undergone probable prime tests such
Key schedule
In cryptography, the so-called product ciphers are a certain kind of cipher, where the (de-)ciphering of data is typically done as an iteration of rounds. The setup for each round is generally the sam
Substitution–permutation network
In cryptography, an SP-network, or substitution–permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES (Rijndael), 3-Way, Kalyna, Kuznyech
Hash chain
A hash chain is the successive application of a cryptographic hash function to a piece of data. In computer security, a hash chain is a method to produce many one-time keys from a single key or passwo
Beaufort cipher
The Beaufort cipher, created by Sir Francis Beaufort, is a substitution cipher similar to the Vigenère cipher, with a slightly modified enciphering mechanism and tableau. Its most famous application w
Cryptographically secure pseudorandom number generator
A cryptographically secure pseudorandom number generator (CSPRNG) or cryptographic pseudorandom number generator (CPRNG) is a pseudorandom number generator (PRNG) with properties that make it suitable
Software taggant
A software taggant is a cryptographic signature added to software that enables positive origin identification and integrity of programs. Software taggants use standard PKI techniques (see Public key i
Bach's algorithm
Bach's algorithm is a probabilistic polynomial time algorithm for generating random numbers along with their factorizations, named after its discoverer, Eric Bach. It is of interest because no algorit
Summation generator
The summation generator, created in 1985, by Rainer Rueppel, was a cryptography and security front-runner in the late 1980s. It operates by taking the output of two LFSRs through an adder with carry.
ISMACryp
The ISMA Encryption and Authentication, Version 1.1 specification (or ISMACryp) specifies encryption and message authentication services for MPEG-4 over RTP streams. It was defined by the Internet Str
Symmetric-key algorithm
Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there
A random password generator is software program or hardware device that takes input from a random or pseudo-random number generator and automatically generates a password. Random passwords can be gene
Linear-feedback shift register
In computing, a linear-feedback shift register (LFSR) is a shift register whose input bit is a linear function of its previous state. The most commonly used linear function of single bits is exclusive
Verifiable random function
In cryptography, a verifiable random function (VRF) is a public-key pseudorandom function that provides proofs that its outputs were calculated correctly. The owner of the secret key can compute the f