Practical Symmetric On-Line Encryption

Abstract. This paper addresses the security of symmetric cryptosystems in the blockwise adversarial model. At Crypto 2002, Joux, Martinet and Valette have proposed a new kind of attackers against several symmetric encryption schemes. In this paper, we first show a generic technique to thwart blockwise adversaries for a specific class of encryption schemes. It consists in delaying the output of the ciphertext block. Then we provide the first security proof for the CFB encryption scheme, which is naturally immune against such attackers.

• Type: Conference
• Year: 2003
• Where: FSE
• Authors: Pierre-Alain Fouque, Gwenaëlle Martinet, Guillaume Poupard
• Keywords: Blockwise Adversarial Model, Cryptography, Encryption Scheme, FSE 2003, Symmetric Encryption Schemes