As a soulbound token, the Phemex Soul Pass and its metadata are present and verifiable on-chain. Initially, this on-chain data will be fully public but we are keeping a close eye on the technological strides being made in the field of programmable privacy. In the future, if Phemex Soul Pass holders do not want their PSP information to be public, one option can be to store the data off-chain while leaving a hash of it on-chain. The PSP holder would then be able to reveal the contents of their Soul Pass only when they want to.
Another method to enhance SBT privacy is through zero-knowledge proofs. Since ZKPs can be used to prove the veracity of an arbitrary statement without revealing anything more than the statement itself, they enable SBT holders to prove their legitimacy without having to expose their identity or SBT metadata. Designated-verifier proofs and verifiable delay functions are additional powerful mechanisms that build on top of ZKP as mentioned in Weyl, Ohlhaver, and Buterin’s paper on Decentralized Society. As cryptographic techniques continue to develop regarding privacy, Phemex will assess their viability and look to apply them to the Phemex Soul Pass.