Cryptanalysis of an Encryption Scheme Based on Blind Source Separation

TL;DR

This paper critically analyzes a BSS-based encryption scheme, revealing multiple security vulnerabilities including susceptibility to known-plaintext, chosen-plaintext, and ciphertext attacks, and discusses its limitations in achieving cryptographic security.

Contribution

It provides the first cryptanalysis of Lin et al.'s BSS-based encryption, identifying key security flaws and limitations in its cryptographic robustness.

Findings

Scheme is vulnerable to known/chosen-plaintext attacks

Existence of ciphertext-only differential attack

Low key sensitivity and divide-and-conquer vulnerabilities

Abstract

Recently Lin et al. proposed a method of using the underdetermined BSS (blind source separation) problem to realize image and speech encryption. In this paper, we give a cryptanalysis of this BSS-based encryption and point out that it is not secure against known/chosen-plaintext attack and chosen-ciphertext attack. In addition, there exist some other security defects: low sensitivity to part of the key and the plaintext, a ciphertext-only differential attack, divide-and-conquer (DAC) attack on part of the key. We also discuss the role of BSS in Lin et al.'s efforts towards cryptographically secure ciphers.