We’re rewarding the question askers & reputations are being recalculated! Read more.

PRESENT is a lightweight block cipher with a 64-bit block size and an 80 or 128 bit key.

PRESENT is an "ultra-lightweight block cipher" developed in 2007. It has a 64-bit block size and an 80 or 128 bit key, and internally uses 31 rounds of a substitution-permutation network based on a single 4-bit S-box. It is included (together with CLEFIA) in the ISO/IEC 29192-2:2012 standard for lightweight block ciphers.

See also:

history | excerpt history