Batch Pairing Delegation

Abstract. Pairing-based cryptography (PBC) has enabled the construction of many cryptographic protocols. However, there are scenarios when PBC is too heavyweight to use, such as when the computing devices are resource-constrained. Pairing delegation introduced in [19] provides a solution by offloading the computation to more powerful entities. In this paper, we introduce the concept of, and construct several protocols for, batch pairing delegation, which offers significantly improved efficiency over multiple runs of state-of-the-art (non-batch) delegation protocols. We prove the security of our proposed protocols in the model we formalized for batch pairing delegation. Also, we have implemented our protocols in software for experimentation. Moreover, we argue that the secure delegation of pairing computation, batched or not, requires different protocols depending on the semantic meaning of the pairings. We propose a taxonomy that classifies pairings into seven types to assist in choosing the right delegation protocol. Finally, we propose a novel application of pairing delegation in trusted computing — we show how pairing delegation can be leveraged to build a secure coprocessor for pairing computation more cost-effectively.