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In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called blocks. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage and exchange of data, where such data is secured and authenticated via encryption.
A block cipher uses blocks as an unvarying transformation. Even a secure block cipher is suitable for the encryption of only a single block of data at a time, using a fixed key. A multitude of modes of operation have been designed to allow their repeated use in a secure way to achieve the security goals of confidentiality and authenticity. However, block ciphers may also feature as building blocks in other cryptographic protocols, such as universal hash functions and pseudorandom number generators.
cryptography, a blockcipher is a deterministic algorithm that operates on fixed-length groups of bits, called blocks. Blockciphers are the elementary...
cryptography, a Feistel cipher (also known as Luby–Rackoff blockcipher) is a symmetric structure used in the construction of blockciphers, named after the...
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...
stream. Stream ciphers represent a different approach to symmetric encryption from blockciphers. Blockciphers operate on large blocks of digits with...
In cryptography, the Iraqi blockcipher was a blockcipher published in C source code form by anonymous FTP upload around July 1999, and widely distributed...
Standards and Technology (NIST) in 2001. AES is a variant of the Rijndael blockcipher developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen...
that securely combining separate confidentiality and authentication blockcipher operation modes could be error prone and difficult. This was confirmed...
1976. Symmetric key ciphers are implemented as either blockciphers or stream ciphers. A blockcipher enciphers input in blocks of plaintext as opposed...
This article summarizes publicly known attacks against blockciphers and stream ciphers. Note that there are perhaps attacks that are not publicly known...
breaks all blockciphers (CBC ciphers) used in SSL 3.0 unless mitigated by the client and/or the server. See § Web browsers. AEAD ciphers (such as GCM...
In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with...
implementations of blockciphers. Blockciphers are defined as being deterministic and operating on a set number of bits (termed a block) using a symmetric...
between (potentially similar) segments of the encrypted message. For blockciphers, the use of an IV is described by the modes of operation. Some cryptographic...
distinct ciphers: a blockcipher and a stream cipher. When used in encryption mode the data are first encrypted using the 64-bit blockcipher in CBC mode...
the ciphers' block-size (typically 128 bits). Modes are therefore rules on how to repeatedly apply the ciphers' single-block operations. Cipher-block chaining...
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