The latter is more cumbersome to use, so it's only employed when necessary, for example in the analysis of arbitrary-precision arithmetic algorithms, like those used in cryptography.

In the history of cryptography, codes were once common for ensuring the confidentiality of communications, although ciphers are now used instead.

In cryptography, a cipher ( or cypher ) is an algorithm for performing encryption or decryption — a series of well-defined steps that can be followed as a procedure.

Historically, cryptography was split into a dichotomy of codes and ciphers ; and coding had its own terminology, analogous to that for ciphers: " encoding, codetext, decoding " and so on.

* symmetric key algorithms ( Private-key cryptography ), where the same key is used for encryption and decryption, and

* asymmetric key algorithms ( Public-key cryptography ), where two different keys are used for encryption and decryption.

The introduction of DES is considered to have been a catalyst for the academic study of cryptography, particularly of methods to crack block ciphers.

In the 1970s there were very few cryptographers, except for those in military or intelligence organizations, and little academic study of cryptography.

* Eve ( cryptography ), a placeholder name for an archetypal eavesdropper in fields such as cryptography and physics

Elliptic curve cryptography is vulnerable to a modified Shor's algorithm for solving the discrete logarithm problem on elliptic curves.

* Eiffel Encryption Library: Open source cryptography library for the Eiffel language

* FIPS 140 Security requirements for cryptography modules

The Communications-Electronics Security Group ( CESG ) of GCHQ provides assistance to government departments on their own communications security: CESG is the UK national technical authority for information assurance, including cryptography.

Although related, the distinctions among these measures mean that a random variable with high Shannon entropy is not necessarily satisfactory for use in an extractor and so for cryptography uses.

This will have significant implications for cryptography if a large quantum computer is ever built.

The goal in finding these " hard " instances is for their use in public key cryptography systems, such as the Merkle-Hellman knapsack cryptosystem.

SHA-1 HMAC Generation. In cryptography, a hash-based message authentication code ( HMAC ) is a specific construction for calculating a message authentication code ( MAC ) involving a cryptographic hash function in combination with a secret cryptographic key.

The polyalphabetic cipher was, at least in principle, for it was not properly used for several hundred years, the most significant advance in cryptography since before Julius Caesar's time.

The National Security Agency ( NSA ) is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U. S. government communications and information systems, which involves information security and cryptanalysis / cryptography.

Leo Marks describes inventing such a system for the British Special Operations Executive during World War II, though he suspected at the time that it was already known in the highly compartmentalized world of cryptography, as for instance at Bletchley Park.

In cryptography, oracles are used to make arguments for the security of cryptographic protocols where a hash function is used.

In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks, with an unvarying transformation that is specified by a symmetric key.

In non-technical usage, a " cipher " is the same thing as a " code "; however, the concepts are distinct in cryptography.

In cryptography, key size or key length is the size measured in bits of the key used in a cryptographic algorithm ( such as a cipher ).

It is one of the earliest practical examples of key exchange implemented within the field of cryptography.

" An astonishing share of the open literature in cryptography in the 1970s and 1980s dealt with the DES, and the DES is the standard against which every symmetric key algorithm since has been compared.

Elliptic curve cryptography ( ECC ) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields.

Public-key cryptography is based on the intractability of certain mathematical problems.

In cryptography, encryption is the process of transforming information ( referred to as plaintext ) using an algorithm ( called a cipher ) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key.

The result of the process is information ( in cryptography, referred to as ciphertext ).

Factorization of large integers is believed to be a computationally very difficult problem, and the security of many modern cryptography systems is based upon its infeasibility.

Information security uses cryptography to transform usable information into a form that renders it unusable by anyone other than an authorized user ; this process is called encryption.

In cryptography, the International Data Encryption Algorithm ( IDEA ) is a block cipher designed by James Massey of ETH Zurich and Xuejia Lai and was first described in 1991.

The presumed difficulty of this problem is at the heart of widely used algorithms in cryptography such as RSA.

The problem often arises in resource allocation where there are financial constraints and is studied in fields such as combinatorics, computer science, complexity theory, cryptography and applied mathematics.

* MARS ( cryptography ), a block cipher that was IBM's submission to the Advanced Encryption Standard process.

In cryptography, a random function can be a useful building block in enabling cryptographic protocols.

In cryptography, Triple DES is the common name for the Triple Data Encryption Algorithm ( TDEA or Triple DEA ) block cipher, which applies the Data Encryption Standard ( DES ) cipher algorithm three times to each data block.

In cryptography, he designed with Eli Biham the BEAR, LION and Tiger cryptographic primitives, and coauthored with Biham and Lars Knudsen the block cipher Serpent, one of the finalists in the AES competition.

* Cipher block chaining, in cryptography: a block cipher mode that provides confidentiality but not message integrity

In cryptography, RC5 is a block cipher notable for its simplicity.

A block cipher is one of the most basic primitives in cryptography, and frequently used for data encryption.

In cryptography, modes of operation is the procedure of enabling the repeated and secure use of a block cipher under a single key.

In cryptography, RC6 is a symmetric key block cipher derived from RC5.

The ASF container can optionally support digital rights management using a combination of elliptic curve cryptography key exchange, DES block cipher, a custom block cipher, RC4 stream cipher and the SHA-1 hashing function.

In cryptography, CAST-128 ( alternatively CAST5 ) is a block cipher used in a number of products, notably as the default cipher in some versions of GPG and PGP.

* CRYPTON, a block cipher in cryptography

An analysis of an older scheme used in WMA reveals that it is using a combination of elliptic curve cryptography key exchange, DES block cipher, a custom block cipher, RC4 stream cipher and the SHA-1 hashing function.

In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers.

In cryptography, 3-Way is a block cipher designed in 1994 by Joan Daemen.

* Block size ( cryptography ), the minimal unit of data for block ciphers.

In cryptography, a Feistel cipher is a symmetric structure used in the construction of block ciphers, named after the German-born physicist and cryptographer Horst Feistel who did pioneering research while working for IBM ( USA ); it is also commonly known as a Feistel network.

In cryptography, Lucifer was the name given to several of the earliest civilian block ciphers, developed by Horst Feistel and his colleagues at IBM.