Use peppers with Bcrypt (HMAC + Bcrypt)

Mohamed Waleed

11/29/22, 12:40 AM

Is it useful to combine HMAC with Bcrypt ?
If it so, should I do the HMAC on the password before "Bcrypt"ing it ? or should I do the HMAC on the Bcrypt output ?

1 + 1

bcrypt

hmac

password-hashing

Stephen Touset

11/29/22, 2:41 AM

Rather than do this yourself, just use argon2 which has an explicit parameter for this.

Score:1

Crypto

SAI Peregrinus

11/29/22, 1:58 AM

The goal of a pepper is to protect passwords in the event that a database of password hashes is compromised but other parts of the authentication system are not compromised.

Password hashing functions' output contains their input parameters, salt, and the digest, so obscuring it irretrievably via HMAC would make it impossible to verify a user's password. Storing the plaintext password hash output next to the "peppered" HMACed output would leak the "unpeppered" value. Therefore, you apply the pepper on the input.

Nothing about this differs from hash to hash, it's the same for bcrypt as it is for PBKDF2 or Argon2 or Pufferfish2 or any other Password Hashing Function...

0 + 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Use peppers with Bcrypt (HMAC + Bcrypt)

TH: ใช้พริกไทยกับ Bcrypt (HMAC + Bcrypt)

RO: Utilizați ardei cu Bcrypt (HMAC + Bcrypt)

RU: Используйте перец с Bcrypt (HMAC + Bcrypt)

VI: Sử dụng ớt với Bcrypt (HMAC + Bcrypt)

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