Threshold Cryptography for Mobile Ad Hoc Networks

The area of Threshold Cryptography investigates the design and analysis of protocols that distribute, in wired networks, cryptographic actions usually performed by a single party into multi-party variants, where the original action is successfully performed only if at least a certain threshold of the participants are available and not corrupted. As of today, several examples of threshold cryptographic protocols (e.g., signatures, public-key cryptosystems, zero-knowledge protocols, etc.) are being investigated in the Cryptography literature. We note that the impact of the Threshold Cryptography paradigm is of even greater importance to study the security of other types of communication networks, such as Mobile Ad Hoc Networks, where the existence and availability of trusted authorities is severely limited by intrinsic network features, and problems such as avoiding a “single point of failure”, or, more generally, “service availability”, become crucial. In this paper we formalize, investigate and present satisfactory solutions for the general problem of Threshold Cryptography in Mobile Ad Hoc Networks. Although we restrict our study to the cryptographic operation of digital signatures schemes, our definitional approaches can be extended to most other cryptographic actions studied in Threshold Cryptography.