Block cipher facts for kids
In cryptography, a block cipher is a symmetric key cipher which operates on a groups of bits of fixed length, called blocks, using an exact transformation. During encryption, a block cipher algorithm might take (for example) a 128bit block of plaintext as input, and output a corresponding 128bit block of ciphertext. The exact transformation is controlled using a second input — the secret key. Decryption is similar: the decryption algorithm takes, in this example, a 128bit block of ciphertext together with the secret key, and output the original 128bit block of plaintext.
One of the early block cipher designs was the Data Encryption Standard (DES), developed at IBM and published as a standard in 1977. A successor to DES, the Advanced Encryption Standard (AES); also using block cipher, was adopted in 2001.
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The development of the boomerang attack enabled differential cryptanalysis techniques to be applied to many ciphers that had previously been deemed secure against differential attacks
See also
In Spanish: Cifrado por bloques para niños