[Pharo-project] CRC in System-Hashing?

I need to calculate CRC for Git and couldn't find it in the system packages (I guess I'd find it in Cryptography). Since Pharo has a system package called "System-Hashing" I was wondering if anyone sees a reason why CRC should not be part of that package. That would also allow the Zip implementation to use the system CRC function (at the moment Zip implements its own CRC check). Another thing: going through Sytem-Hashing I noticed that there are two implementations for SHA1: "SHA1" and "SecureHashAlgorithm". They both have the exact same class comment but vary slightly in the messages they implement (although most of them are present in both classes). Can we remove one? Cheers, Max