A PUBLIC KEY MANAGEMENT SCHEME AND THRESHOLD-MULTISIGNATURE SCHEME FOR MOBILE AD HOC NETWORKS

Mobile ad hoc networks offer communication over a shared wireless channel without any pre-existing infrastructure. Threshold digital signatures are an important cryptographic tool used in most existing key management schemes for mobile ad hoc networks. This paper proposes a threshold-multisignature scheme designed specifically for mobile ad hoc networks. The signature scheme allows a subset of shareholders with threshold t, to sign an arbitrary message on behalf of the group. The group signature is publicly verifiable and allows any outsider to establish the identity of the individual signers. The paper proposes a self-certified public key issuing protocol that allows negotiation between a single entity and a distributed certificate authority for an implicit self-certified public key. The main objective of the paper is to find a key management scheme that is suitable for mobile ad hoc networks. As a solution, the paper proposes a public key management scheme, called Ad Hoc Public Key Management (AdHocPKM). AdHocPKM integrates the advantages of distributed key generation, threshold-multisignatures, self-certified public keying and self-certificates to yield a secure, trustworthy key management service with a high availability feature. The proposed scheme is operated solely by the end-users and does not require any offline trusted third party or a priori sharing of keying material. This addresses the major problem in providing key management services for mobile ad hoc networks, without compromising security.