This is really neat. Recently I explored similar functionality for relational databases and only got as far as implementing column-level encryption [0] in this Go library [1], but without support for querying the encrypted data. HashiCorp Vault's transit secrets engine supports Convergent Encryption [2] which provides limited ability to query the encrypted data, but I haven't yet experimented with it. If anyone is doing something like this in production, would love to hear about your experience.

[0]: https://en.wikipedia.org/wiki/Column_Level_Encryption

[1]: https://github.com/bincyber/go-sqlcrypter

[2]: https://www.vaultproject.io/docs/secrets/transit#convergent-...