An improved online/offline identity-based signature scheme for WSNs

Online/offline signature schemes allow the signer to generate an online signature in real-time from a precomputed offline signature when presented with a document. Such schemes are particularly useful in resource-constrained wireless sensor network applications. In this paper, we describe an identity-based online/offline signature scheme based on bilinear maps, and prove the security of the scheme assuming the intractability of the Computational Diffie-Hellman Problem. More precisely, under the random oracle model, our scheme is proved to be secure against existential forgery on adaptively chosen message attack. As an extension to our scheme, we demonstrate how the scheme can be extended to allow a single user to sign multiple messages.