From the white paper, https://www.evernym.com/wp-content/uploads/2017/07/What-Goes-On-The-Ledger.pdf, the revocation registries are published by the issuer and stored in Sovrin. How fast (and big) does the revocation registration grow? If 1000s of claims are revoked, what are the implications on the run time performance during validation/verification?
The revocation registry is persisted to the ledger as a single 256-bit number. Whether it has 1 revocation “in” it, or 1 million revocations “in” it, it’s still a single 256-bit number. Proving that your credential is not revoked takes approximately the same amount of math no matter how heavily the revocation feature is used. See https://github.com/hyperledger/indy-hipe/blob/master/text/0011-cred-revocation/README.md. However, each publication of a revocation update to the ledger adds a transaction that has to be downloaded and accounted for in the final math. This imposes a modest cost on the prover (nothing significant on the verifier). In practical terms, it would be bad for the efficiency of provers if an issuer revoked thousands of times per day. For thousands of revocations over years, it probably doesn’t matter much.