On Mon, Mar 27, 2017 at 6:57 AM, Niall Douglas via Boost
The point being made here is that you need to use a high quality secure hash when writing data to storage. That way after power loss you can determine if the database store is truly in a consistent and valid state rather than being tricked into thinking it is, and then unwittingly destroying more user data.
Oh...I misunderstood. The hash function in NuDB is not used to calculate a digest of the value, its used only to determine which bucket to place the key in the hash table. NuDB is essentially an on-disk unordered_map. That is why the hash function does not need to be cryptographically secure. In the use-cases for which NuDB is designed (blockchain applications) the key used for insertion is usually a cryptographic digest of the value. So its up to the application to use a cryptographically secure hash function for computing keys. However, this is part of the caller's implementation and not part of the library.