Generic Attacks on Unbalanced Feistel Schemes with Contracting Functions

In this paper, we describe generic attacks on unbalanced Feistel schemes with contracting functions. These schemes are used to construct pseudo-random permutations from kn bits to kn bits by using d pseudo-random functions from (k - 1)n bits to n bits. We describe known plaintext attacks (KPA) and non-adaptive chosen plaintext attacks (CPA-1) against these schemes with less than 2kn plaintext/ciphertext pairs and complexity strictly less than O(2kn ) for a num

• Type: Conference
• Year: 2006
• Where: ASIACRYPT
• Authors: Jacques Patarin, Valérie Nachef, Côme Berbain
• Keywords: ASIACRYPT 2006, Cryptology, Kn Bits, Plaintext Attacks, Unbalanced Feistel Schemes