A Mercurial-Based Secure Authentication and Reputation Framework for the Multi-Context Metaverse

This paper describes SPARTA, a protocol designed to let people create multiple separate avatars (digital representations of users in virtual spaces) in the metaverse while keeping those avatars unlinkable, meaning no one can connect different avatars to the same real person. The protocol uses mercurial signatures (a cryptographic technique that allows flexible key usage) and zero-knowledge proofs (ways to prove something is true without revealing how you know it) to enable secure authentication and prevent misuse through a reputation system based on time-based hash chains (sequences of data linked by timestamps).