While libmongocrypt is responsible for all the encryption and this is successfully bundled with this NuGet package you still need either "mongod" or "crypt_shared" libraries as well in order to mark the encrypted fields etc.

As crypt_shared is now the recommended default way to do this and MongoDB.Driver.Encryption is stand-alone and not usable without one of these libraries we should seriously consider bundling crypt_shared with this package in order to make setup, deployment and testing much easier for our customers.

Note: MongoDB.Driver.Encryption currently brings in libmongocrypt for various architectures already so this is likely a very low effort piece of work. The defaults for finding the library should handle where the NuGet package deploys it to in the same way as it does for libmongocrypt.