A Real-Time Attack on the GMR-2 Encryption Algorithm in Satellite Phones

• Published in: China communications Vol. 14; no. 11; pp. 209 - 217
• Main Authors: Liu, Jingmei, Zhao, Linsen, Liu, Jingwei
• Format: Journal Article
• Language: English
• Published: China Institute of Communications 01.11.2017; National Key Laboratory of Integrated Service Networks, Xidian University, Xi'an 710071, China%College of Electronic Engineering, Xi'an University of Post & Telecommunications, Xi'an 710061, China
• Subjects: Algorithm design and analysis; Ciphers; Clocks; Encryption; GMR-1; GMR-2; read-collision; Registers; satellite phones; Satellites; the known plaintext attack; the known plaintext attack; GMR-1; GMR-2; read-collision; satellite phones
• ISSN: 1673-5447
• DOI: 10.1109/CC.2017.8233661

In this paper, we present one method to attack on the GMR-2 algorithm used in satellite phone under the chosen-plaintexts. First using the relationship of the rows of the two s-boxes and outputs of the F coordinate, we attack on the GMR-2 algorithm. Then we deduce the happening probability of read-collision, and analyze its mathematical expectation. Finally, combining with the read-collision, we present an improved method to attack on the GMR-2 algorithm. The research results show that the complexity of the improved algorithm is about 2^20, and the session key Kc can be recovered in about 0.3 seconds. Compared with the available method, our method takes less time than the guess-and-decide attack method which is 700 s.