Verifiable Anonymous Identities and Access Control in Permissioned Blockchains
This addresses privacy and regulatory compliance challenges for entities using permissioned blockchains, though it appears incremental as it builds on existing blockchain and access control concepts.
The paper tackles the problem of identity and access control in permissioned blockchains by proposing the ChainAchor system, which provides anonymous but verifiable identities and unlinkable transactions while allowing optional identity disclosure for compliance.
In this paper we address the issue of identity and access control within shared permissioned blockchains. We propose the ChainAchor system that provides anonymous but verifiable identities for entities on the blockchain. ChainAchor also provides access control to entities seeking to submit transactions to the blockchain to read/verify transactions on the the permissioned blockchain. Consensus nodes enforce access control to the shared permissioned blockchain by a simple look-up to a (read-only) list of anonymous members' public-keys. ChainAnchor also provides unlinkability of transactions belonging to an entity on the blockchain. This allows for an entity to optionally disclose their identity when a transaction is called into question (e.g. regulatory or compliance requirements), but without affecting the anonymity and unlinkability of their remaining transactions.