Paper 2017/655
A Real-time Inversion Attack on the GMR-2 Cipher Used in the Satellite Phones
Jiao Hu, Ruilin Li, and Chaojing Tang
Abstract
The GMR-2 cipher is a type of stream cipher currently being used in some Inmarsat satellite phones. It has been proven that such a cipher can be cracked using only one single-frame (15 bytes) known keystream but with a moderate executing times. In this paper, we present a new thorough security analysis of the GMR-2 cipher. We first study the inverse properties of the cipher's components to reveal a bad one-way character of the cipher. By then introducing a new concept called ``valid key chain" according to the cipher's key schedule, we propose an unprecedented real-time inversion attack using a single-frame keystream. This attack comprises three phases: (1) table generation; (2) dynamic table look-up, filtration and combination; and (3) verification. Our analysis shows that, using the proposed attack, the size of the exhaustive search space for the 64-bit encryption key can be reduced to approximately $2^{13}$ when a single-frame keystream is available. Compared with previous known attacks, this inversion attack is much more efficient. Finally, the proposed attack is carried out on a 3.3-GHz PC, and the experimental results thus obtained demonstrate that the 64-bit encryption-key could be recovered in approximately 0.02 s on average.
Note: Major revision on Section 5.3 and some typos correction.
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- Published elsewhere. SCIENCE CHINA Information Sciences
- DOI
- 10.1007/s11432-017-9230-8
- Keywords
- Satellite PhoneStream CipherGMR-2CryptanalysisInversion Attack
- Contact author(s)
- securitylrl @ gmail com
- History
- 2017-09-17: last of 2 revisions
- 2017-07-05: received
- See all versions
- Short URL
- https://ia.cr/2017/655
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2017/655,
author = {Jiao Hu and Ruilin Li and Chaojing Tang},
title = {A Real-time Inversion Attack on the {GMR}-2 Cipher Used in the Satellite Phones},
howpublished = {Cryptology {ePrint} Archive, Paper 2017/655},
year = {2017},
doi = {10.1007/s11432-017-9230-8},
url = {https://eprint.iacr.org/2017/655}
}
