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1

One serious about password-based cryptography must not walk away from KDF_PBKDF2, but run to Argon2 (or scrypt if it's more readily available)! Bitcoin mining has (in 2020) shown that dedicated ASICs performing SHA-256 at high rate (220 TH/s) and efficiency (15 pJ/H) can become commercially available for few thousand US dollars. This makes it untenable to ...


2

Generally we look at strength by looking at the order $O$ that it adds to the password search when an attacker is trying to guess passwords. That's just the same as the number of iterations basically, assuming a salt and correct password hash. Often it is simpler to just use bits, which is basically the $\log_2$ of the order. So if a password strength is an ...


1

I guess you are referring to this whitepaper, so I will refer to it in my answer. First, I think you misunderstood part of the protocol (illustrated in Figure 1): the KDF is not AES-CFB8. A KDF is a Key Derivation Function: in this particular case, it basically acts as a hash function, transforming the inputs into a random-like stream of bytes We assume the ...


-3

SHA256 Hash Generator will allow you to check the sha256 hash of any string.


2

Or would it be better to use something like HKDF? Generally? Yes. Using HKDF is preferred, if only to communicate clearer what you're actually doing here. Is it acceptable to use PBKDF2 with just 1 iteration to do the simple key expansion that I need? Yes. To explain this, we first need to understand how PBKDF2 works. First, note that it compute $\ell$ ...


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