A Mutual Authentication Protocol with Resynchronisation Capability for Mobile Satellite Communications

Many peer-to-peer security protocols proposed for wireless communications use one-time shared secrets for authentication purposes. This paper analyses online update mechanisms for one-time shared secrets. A new type of attack against update mechanisms, called desynchronisation attack, is introduced. This type of attack may lead to a permanent denial of service condition. A case study demonstrates the effectiveness of desynchronisation attacks against a security protocol for mobile satellite communications. A new mutual authentication protocol for satellite communications, incorporating a resynchronisation capability, is proposed to counter the disruptive effects of desynchronisation attacks. The new protocol has an esynchronisation phase that is initiated whenever desynchronisation is suspected. Thus, the possibility of causing permanent denial of service conditions by mounting desynchronisation attacks is eliminated. A security analysis of the proposed protocol establishes its resistance against attacks like replay attacks, dictionary attacks, and desynchronisation attacks.