Building PRFs from PRPs

Abstract. We evaluate constructions for building pseudo-random functions (PRFs) from pseudo-random permutations (PRPs). We present two constructions: a slower construction which preserves the security of the PRP and a faster construction which has less security. One application of our construction is to build a wider block cipher given a block cipher as a building tool. We do not require any additional constructions--e.g. pseudo-random generators--to create the wider block cipher. The security of the resulting cipher will be as strong as the original block cipher. Keywords. pseudo-random permutations, pseudo-random functions, concrete security, block ciphers, cipher feedback mode.

• Type: Conference
• Year: 1998
• Where: CRYPTO
• Authors: Chris Hall, David Wagner, John Kelsey, Bruce Schneier
• Keywords: Block Ciphers, CRYPTO 1998, Cryptology, Pseudo-random, Wider Block Cipher