Square (cipher)

Square
General
DesignersJoan Daemen, Vincent Rijmen
First published1997
SuccessorsAES, CRYPTON, Twofish, Serpent
Cipher detail
Key sizes128 bits
Block sizes128 bits
Structuresubstitution–permutation network
Rounds8

In cryptography, Square (sometimes written SQUARE) is a block cipher invented by Joan Daemen and Vincent Rijmen. The design, published in 1997, is a forerunner to Rijndael, which has been adopted as the Advanced Encryption Standard. Square was introduced together with a new form of cryptanalysis discovered by Lars Knudsen, called the "Square attack".

The structure of Square is a substitution–permutation network with eight rounds, operating on 128-bit blocks and using a 128-bit key.

Square is not patented.