Mnemonic to Seed - confused

Developers Misc Dev Talk
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Can someone clarify how you get from the Mnemonic to the Seed in Yoroi and Daedalus, because it seems to be different.

But can it be different? Because that would mnemonics on one program can not be recovered on the other program - is that right?

Daedalus here

Seems to use blake2b (sorry to not post the Haskell but I can’t understand that language, but this python code does work)

def hash_serialized(s):
    return hashlib.blake2b(s, digest_size=32).digest()

Yoroi is based on the rust code I believe: here

This is using PBKDF2 with sha512 as the function.

pub fn from_mnemonic_string(mnemonics: &MnemonicString, password: &[u8]) -> Self {
    let mut salt = Vec::from("mnemonic".as_bytes());
    salt.extend_from_slice(password);
    let mut mac = Hmac::new(Sha512::new(), mnemonics.0.as_bytes());
    let mut result = [0;SEED_SIZE];
    pbkdf2(&mut mac, &salt, 2048, &mut result);
    Self::from_bytes(result)
}
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I found this and this.

So it seems rust-cardano follows the BIP39 standard of generating a seed with a password, whereas cardano-sl doesn’t so they use a faster hash function (blake2b) instead of PBKDF2.

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That makes the wallets incompatible right?

You can’t restore a Yoroi mnemonic on Daedalus and vice versa.

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Why would you want a faster hash function? Wouldn’t you want a SLOW hash function for this? LOL. I get what they are saying in that post about “pointless” but still, not really a selling point.

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@vantuz-subhuman

Is Yoroi/Rust fully BIP39 + BIP44 compatible?

Is this the standard going forward? I’m assuming someone building a wallet would want to copy Yoroi not Daedalus.

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That makes the wallets incompatible right?

Right, Yoroi and Daedalus mnemonics are incompatible. Yoroi is 15 words and Daedalus is 12 words.

Why would you want a faster hash function? Wouldn’t you want a SLOW hash function for this?

Yeah as they said in the second link, slower hash functions were used to prevent fast brute forcing, since user provided passwords could be bad entropy, but since Daedalus doesn’t generate a seed with a password they used something faster just because they could I guess?

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Supposed to be fully compatible, afaik, yes.

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But in doing so they become incompatible with what is now a pretty industry wide standard? Very lame.