Concise Mercurial Subvector Commitments: Definitions and Constructions

Vector commitment and its variants have attracted a lot of attention recently as they have been exposed to a wide range of applications in blockchain. Two special extensions of vector commitments, namely subvector commitments and mercurial commitments, have been proposed with attractive features that are desirable in many applications. Nevertheless, to the best of our knowledge, a single construction satisfying all those attractive features is still missing. In this work, we analyze those important properties and propose a new primitive called mercurial subvector commitments, which are efficiently updatable, mercurial hiding, position binding, and aggregatable. We formalize the system model and security model for such a primitive and present a concrete construction with security proofs to show that it satisfies all of the properties. Moreover, we also illustrate some applications of mercurial subvector commitments, including zero-knowledge sets and blockchain with account-based models.