We are using absolute state of the art cryptography (post-military-grade? 😉 ). Most of it was designed by Daniel J Bernstein @ [https://cr.yp.to/] - and not the NSA.
This is what most modern protocols use. (Things like AES and RSA are still okay, but old and slow.)
To get top security with good speeds, we use:
Key Exchange/Setup: ECDH with X25519
key Derivation/Iteration: HKDF with BLAKE2b-256
Encryption: CHACHA20 + POLY1305
Our cryptography has been audited by Cure53, well known German auditing experts.
Search terms: