I'm implementing an application that from a password has to derive two keys, one for authentication with the server, one for encryption. I'm using Java, with JCA and Bouncy Castle.
So far, to generate a key from the password I was using PBKDF2, like this:
SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA512", BC); PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, iterations, keyLength); SecretKey passwordKey = secretKeyFactory.generateSecret(keySpec);
but in the two examples I found of HKDF:
they start with HmacSHA256, not PBKDF2. Why is that? What are the pros and cons of these two algorithms in this case?