When a VURL key has multiple equivilant keys that all use the same hash, verifying the VURL key currently has to verify each equivilant key. Usually that is done incrementally, so it only has to read the file once. But it still does redundant work, updating each incremental verifier with each chunk.
This could be improved by caclulating a hash once, and then compare it with a hash value exposed by the Backend. That seems doable but will mean extending the Backend interface, to expose the hash value and type. --Joey