Feature: Encryption at rest

[itsezc]

There is little to no documentation of how SurrealKV handles encryption at rest. This is a very important security factor for choosing SurrealKV (and by extension SurrealDB) over competitors such as Foundation DB, TikV, Postgres etc.

I've previously raised an issue on the surrealdb repository about using Kyber for Encryption on rest / storage, this hasn't received any major feedback; as SurrealKV was still in development at that time.

In many cases, there are many considerations to take with regards to Encryption at rest:

• Storage medium level (Hardware / VMs / Container): there are many cases where this is not possible, especially in the Cloud vendor scene as not all offer them or reliable
• At file / folder level: This is what is suggested by the scope of this issue, encrypting all the necessary files used by SurrealKV

Additional considerations to take into mind would be choosing the appropriate algorithm that is both performant and secure enough for a "post-quantum" world.

Related:

• Feature: Kyber encryption surrealdb#1648
• Why RSA would be a bad choice: https://arxiv.org/pdf/2212.12372.pdf
• https://github.com/samuel-lucas6/ChaCha20-BLAKE3

With all this in mind, heres a few suggested solutions:

• Preferred: XChaCha / XChaCha20-Blake3
• Preferred: Kyber 512 / 1024: https://pq-crystals.org/kyber/ (Although storage encryption is not feasible to the best of my knowledge)
• AES 256 Bit (Traditional option)

These offer decent levels of safety against quantum attacks, and notable choices are for the following reasons:

ChaCha20 has a higher security margin than AES, performs well on older devices, and runs in constant time, unlike AES.

BLAKE3 is fast and evolved from BLAKE, which received a significant amount of cryptanalysis, even more than Keccak (the SHA3 finalist), as part of the SHA3 competition.