A non-delegatable strong designated verifier signature in ID-based setting for mobile environment

Non-delegatability is an interesting property of designated verifier signatures (DVS) as it technically makes a signer responsible for the signer’s actions and protects the privacy of the signer. This property is critical for some financial scenarios when a user is required to do something by itself. As more financial applications are running in a mobile and ubiquitous computing environment, an efficient scheme with a non-delegatability property is desirable. This paper proposes such a scheme in an identity-based setting with detailed proofs. Technically, the scheme combines an identity-based Schnorr style signature and an identification method with an OR proof technique gluing the two parts. It is the second scheme secure in a strict model proposed by Huang et al. And it saves about half the communication and computation costs of the first one.