Strong Diffie Hellman Inversion using Cloudflare's CIRCL library

sdhi.go

package main

import (
    "crypto/rand"
    "crypto/sha256"
    "fmt"
    "github.com/cloudflare/circl/ecc/bls12381"
)

type KDF struct {
    curve *bls12381.G1
}

func hashToScalar(attributes [][]byte) *bls12381.Scalar {
    h := sha256.New()
    for _, attr := range attributes {
        h.Write(attr)
    }
    digest := h.Sum(nil)
    var s bls12381.Scalar
    s.SetBytes(digest)
    return &s
}

func generatePrimaryKey(kdf *KDF) (*bls12381.Scalar, *bls12381.G1, error) {
    sk := new(bls12381.Scalar)
    sk.Random(rand.Reader)
    pk := new(bls12381.G1)
    pk.ScalarMult(sk, bls12381.G1Generator())
    return sk, pk, nil
}

func deriveKeyPair(
    kdf *KDF,
    sk *bls12381.Scalar,
    attributes [][]byte,
) (*bls12381.G1, error) {
    attrHash := hashToScalar(attributes)
    sk.Add(sk, attrHash)
    sk.Inv(sk)
    pk := new(bls12381.G1)
    pk.ScalarMult(sk, bls12381.G1Generator())
    return pk, nil
}

func main() {
    kdf := &KDF{
        curve: bls12381.G1Generator(),
    }

    // Generate primary key
    sk, pk, err := generatePrimaryKey(kdf)
    if err != nil {
        fmt.Println("Error generating primary key:", err)
        return
    }

    fmt.Println("Primary Key (Private):", sk)
    fmt.Println("Primary Key (Public):", pk)

    // Example attributes
    attributes := [][]byte{
        []byte("strong-diffie"),
        []byte("hellman-inversion"),
    }

    // Derive key pair
    derivedPK, err := deriveKeyPair(kdf, sk, attributes)
    if err != nil {
        fmt.Println("Error deriving key pair:", err)
        return
    }

    fmt.Println("Derived Public Key:", derivedPK)
}

terminal

> go run "c:\Users\Hamdaan\Desktop\go\circl.go"
Primary Key (Private): 0x61af1b490c1f1eeacb92d67814a8bfa9ec0aac7ab6d6b3040582e943598a0e07
Primary Key (Public): x: 0x0880273608cd5c7a61aaee18a2b7931dc0106191dc503ee289ac69448f1577b4388b5f7add7b749c379467abed1d2d74
y: 0x0881c6222aba2096ca39fb1f8d647fc4ee156b20b88529a04968789ef7d09946d463d48208240c6c0064a01847009797
z: 0x1622bd1cde8077331f68506388710b7854cf77606b4d4a04a045afbb5bd0e4e06ce3bd754b9f4aea1eb825532acbc409
Derived Public Key: x: 0x17e2c736aa2cd58887e186465a98eb7f4920a66ddfe9d2c8069e832e2d6befb371ba192aea9a2021a5a9ac6a8111dbcd
y: 0x0403d1d08757f65109b14417cda6983822dbfba4ea233574613fa84aefaba1345140012e92b733d4ddc0adcf07426b78
z: 0x0c3571215212066ba7eca5defd9b699400a29b5677520f40c6fb9b1a5f68fe90bb430178b58efb8c2a7e032078f9ef6c