Recovering Decimation-Based Cryptographic Sequences by Means of Linear CAs

Author(s)

Cardell, Sara D. ^[1] ; Aranha, Diego F. ^{[2, 3]} ; Fuster-Sabater, Amparo ^[4]

Affiliation

^[1] Univ Estadual Campinas, IMECC, Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Campinas - Brazil

^[3] Aarhus Univ, Aarhus - Denmark

^[4] CSIC, ITEFI, Madrid - Spain

• Document type: Journal article
• Source: LOGIC JOURNAL OF THE IGPL; v. 28, n. 4, p. 430-448, AUG 2020.
• Web of Science Citations: 0

Abstract

The sequences produced by the cryptographic sequence generator known as the shrinking generator can be modelled as the output sequences of linear elementary cellular automata (CA). These sequences are composed of interleaved m-sequences produced by linear structures based on feedback shifts. This profitable characteristic can be used in the cryptanalysis of this generator. In this work we propose an algorithm that takes advantage of the inherent linearity of these CA and the interleaved m-sequences. Although irregularly decimated generators have been conceived and designed as non-linear ones, in practice they can be easily analysed in terms of simple linear structures. (AU)

• FAPESP's process: 16/50476-0 - Efficiency and security of pre and post quantum cryptographic methods: theory and applications
• Grantee: Ricardo Dahab
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/07246-0 - Construction, decoding and implementation of F_q linear codes. Performanca of SPC product codes and cryptanalysis of the shrinking generators.
• Grantee: Sara Díaz Cardell
• Support Opportunities: Scholarships in Brazil - Post-Doctoral