Thanks for the report.  It appears that this behavior was by design when these
APIs were originally added to System.Data.SQLite.  Changing it now would break
backward compatibility.

Originally the legacy CrypoAPI support functions were designed for internal
communication between the managed components of System.Data.SQLite and the
SQLite interop assembly.  They were not intended to be a public interface.

Finally, the legacy CryptoAPI support is no longer officially supported.  For
the time being, it is still being included in the release builds; however, that
will change at some point.