The next-generation Queryable Encryption feature is now in Public Preview. To learn more about Queryable Encryption, see Queryable Encryption.
MongoDB encrypts all fields in CSFLE with the AEAD AES-256-CBC encryption algorithm.
If you specify deterministic encryption for a field, your application passes a deterministic initialization vector to AEAD.
If you specify random encryption for a field, your application passes a random initialization vector to AEAD.
MongoDB CSFLE uses the encrypt-then-MAC approach to perform authenticated encryption. MongoDB CSFLE uses the HMAC-SHA-512 algorithm to generate your MAC.