Abstract

Two types of attacks against the GSM security algorithm, A5/1, are discussed. The A5/1 system consists of three LFSRs (linear feedback shift registers) which have lengths of 19, 22 and 23 bits respectively. So, the total length of the three registers is 64 bits. The purpose of these attacks is to obtain the initial state of the LFSRs just after the encryption key (Kc) and frame number are loaded, in the light of known plaintext. Both attacks depend on the time-memory attack principle. In other words, the solution space of A5/1, as 2/sup 64/, becomes realizable with M /spl ap/ 2/sup 34.955/ as memory and T /spl ap/ 2/sup 28.365/ as time complexity by distributing the solution space between time and memory optimally.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.