Hashing more than 8000 bytes in SQL Server

Question

SQL Server\'s hashing function HASHBYTES has an input limit of 8000 bytes.

How do you hash larger strings?

Answer 1

You could hash 8k (or 4k or 2k) chunks of the input and then either concatenate those hashes or hash them into a new hash value. This might get difficult though if you have to create a similar algorithm (in an external .NET app for example) to compare hashes created outside of SQL Server.

Another option: Lean on SQL Server's CLR integration and perform the hashing in a .NET assembly.