Randomized Key Chaining Mides with Unforgeability

Abstract

Block cipher based on private key cryptography has widely been employed for bulk encryption and a variety of operation modes have been developed so far. Recently, mode of operation for blockcipher has been revisired in order to develop more rovust cryptosystems under rigorous security models.One of this line of research is the related plaintext chaining (RPC) mode which is secure and can resist against forgeability attack. However, the RPC mode suffers from serious data expansion prblem. In this paper, a randomized key chaining (RKC) mode by employing implicit encoding is proposed which provides the same security property as the RPC mode and is free from the data expansion disadvantage