Analysis of a key distribution scheme in secure multicasting

• Main Author: Maze Gérard
• Format: Article
• Language: English
• Published: De Gruyter 2012-06-01
• Series: Journal of Mathematical Cryptology
• Subjects: finite fields; time-memory tradeoff attack; system of power equations
• Online Access: https://doi.org/10.1515/jmc-2012-0005

This article presents an analysis of the secure key broadcasting scheme proposed by Wu, Ruan, Lai and Tseng [Proceedings of the 25th Annual IEEE Conference on Local Computer Networks (2000), 208–212]. The study of the parameters of the system is based on a connection with a special type of symmetric equations over finite fields. We present two different attacks against the system, whose efficiency depends on the choice of the parameters. In particular, a time-memory tradeoff attack is described, effective when a parameter of the scheme is chosen without care. In such a situation, more than one third of the cases can be broken with a time and space complexity in the range of the square root of the complexity of the best attack suggested by Wu et al. against their system. This leads to a feasible attack in a realistic scenario.