Efficient ID-based non-malleable trapdoor commitment

Non-malleability is an important property in commitment schemes, which can resist to the person-in-the-middle (PIM) attacks within the interaction. In this paper, we focus on the non-malleability of ID-based trapdoor commitment. We first point out some weakness of the definition for Fischlin’s ID-based trapdoor commitments, which we call the partial ID-based trapdoor commitments. Moreover, we present the formal definition for the full ID-based trapdoor commitment and give a concrete construction based on the computational Diffie–Hellman (CDH) assumption. Finally, we use the idea of multi-trapdoor commitments and the technique of non-malleability to propose two efficient interactive full ID-based non-malleable trapdoor commitments in discrete logarithm (DL) system, with/without random oracle respectively.

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► Propose a full ID-based trapdoor commitment scheme based on the CDH assumption.
► Propose an ID-based non-malleable trapdoor commitment scheme in random oracle model.
► Propose an ID-based non-malleable trapdoor commitment scheme without random oracle.