Cryptanalyzing an encryption scheme based on blind source separation

Abstract

Recently, there was a proposal of using the underdetermined blind source separation (BSS) principle to design image and speech encryption. In this paper, we report a cryptanalysis of this BSS-based encryption scheme and point out that it is not secure against known-/chosen-plaintext attack and chosen-ciphertext attack. In addition, we discuss some other security defects of the schemes: (1) it has a low sensitivity to part of the key and to the plaintext; (2) it is weak against a ciphertext-only differential attack; and (3) a divide-and-conquer (DAC) attack can be used to break part of the key. We finally analyze the role of BSS in this approach towards cryptographically secure ciphers.Department of Electronic and Information Engineerin