I am using Argon2 to convert an ECDH exchange result into the correct format for AES-256 encryption. However the library that I am using for Argon2 requires a salt. Are there any weaknesses of using a static, hard-coded salt for the Argon2 key format conversion?

  • $\begingroup$ Related Key derivation functions (KDF): What are? Main purposes? How can they be used? $\endgroup$
    – kelalaka
    Sep 9, 2019 at 15:59
  • $\begingroup$ Would rainbow tables be constructed for SECP521r1 shared secrets?? If so, what would the salt length recommendation be? $\endgroup$
    – SamG101
    Sep 9, 2019 at 16:02
  • $\begingroup$ a shared secret does not need a high work factor KDF to get you a cipher key, you can use a single iteration of a 256-bit hash, or use a 512-bit hash such as SHA-512 if you need additional key material, such as an HMAC key $\endgroup$ Sep 9, 2019 at 23:21


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.