title: Breaking a chaos-noise-based secure communication scheme.
abstract: This paper studies the security of a secure communication scheme based on two discrete-time intermittently chaotic systems synchronized via a common random driving signal. Some security defects of the scheme are revealed: 1) The key space can be remarkably reduced; 2) the decryption is insensitive to the mismatch of the secret key; 3) the key-generation process is insecure against known/chosen-plaintext attacks. The first two defects mean that the scheme is not secure enough against brute-force attacks, and the third one means that an attacker can easily break the cryptosystem by approximately estimating the secret key once he has a chance to access a fragment of the generated keystream. Yet it remains to be clarified if intermittent chaos could be used for designing secure chaotic cryptosystems.
authors.affiliation: Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China. hooklee@mail.com
authors.forename: Shujun
authors.initials: S
authors.lastname: Li
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alvarez
authors.forename: Guanrong
authors.initials: G
authors.lastname: Chen
authors.forename: Xuanqin
authors.initials: X
authors.lastname: Mou
mesh_terms: D000465:Algorithms; D015233:Models, Statistical; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D010825:Physics / Q000379:methods; D012984:Software; D013997:Time Factors