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Consensys / gnark-crypto

gnark-crypto provides elliptic curve and pairing-based cryptography on BN, BLS12, BLS24 and BW6 curves. It also provides various algorithms (algebra, crypto) of particular interest to zero knowledge proof systems.
Apache License 2.0
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How to call mimc to input a string and output the mimc hashed result? #443

Closed fengyin450 closed 1 year ago

fengyin450 commented 1 year ago

In the example of https://play.gnark.io/#, it can be seen that the hash result of "Secret": "0xdeadf00d" is "Hash": "1037254799353855871006189384309576393135431139055333626960622147300727 796413", how to call https://github.com/Consensys/gnark-crypto/blob/master/ecc/bn254/fr/mimc/mimc.go can input Secret to get Hash by implementing mimc function? I tried many methods, but the output is 0 or wrong result. The following is one of them:


func mimcHash(data []byte) string {

    f := bn254.NewMiMC()

    f.Write(data)

    hash := f.Sum(nil)

    hashInt := big.NewInt(0).SetBytes(hash)

    return hashInt.String()

}
gbotrel commented 1 year ago

Hi:

    h := mimc.NewMiMC()
    var message fr.Element
    message.SetString("0xdeadf00d")
    h.Write(message.Marshal())
    res := h.Sum(nil)

    var result fr.Element
    result.SetBytes(res)
    fmt.Println(result.String())