Topic: ShadowCash is mathematically broken. I urge all SDC supporters to join Monero. - page 3. (Read 7970 times)

Shadow-cash

https://github.com/shadowproject/shadow/blob/682891e656b5be2c2b819aa4977aa3b7e9f3f464/src/ringsig.cpp

static int hashToEC(const uint8_t *p, uint32_t len, BIGNUM *bnTmp, EC_POINT *ptRet)
{
    // - bn(hash(data)) * G

    uint256 pkHash = Hash(p, p + len);

    if (!bnTmp || !(BN_bin2bn(pkHash.begin(), EC_SECRET_SIZE, bnTmp)))
    {
        LogPrintf("hashToEC(): BN_bin2bn failed.\n");
        return 1;
    };

    if (!ptRet
        || !EC_POINT_mul(ecGrp, ptRet, bnTmp, NULL, NULL, bnCtx))
    {
        LogPrintf("hashToEC() EC_POINT_mul failed.\n");
        return 1;
    };

    return 0;
};

https://github.com/shadowproject/shadow/blob/master/src/ringsig.cpp#L136
int generateKeyImage(ec_point &publicKey, ec_secret secret, ec_point &keyImage)
{
    // - keyImage = secret * hash(publicKey) * G

    if (publicKey.size() != EC_COMPRESSED_SIZE)
        return errorN(1, "%s Invalid publicKey.", __func__);

    int rv = 0;
    BN_CTX_start(bnCtx);
    BIGNUM   *bnTmp     = BN_CTX_get(bnCtx);
    BIGNUM   *bnSec     = BN_CTX_get(bnCtx);
    EC_POINT *hG        = NULL;

    if (!(hG = EC_POINT_new(ecGrp)))
    {
        LogPrintf("%s: EC_POINT_new failed.\n", __func__);
        rv = 1; goto End;
    };

    if (hashToEC(&publicKey[0], publicKey.size(), bnTmp, hG) != 0)
    {
        LogPrintf("%s: hashToEC failed.\n", __func__);
        rv = 1; goto End;
    };

    if (!bnSec || !(BN_bin2bn(&secret.e[0], EC_SECRET_SIZE, bnSec)))
    {
        LogPrintf("%s: BN_bin2bn failed.\n", __func__);
        rv = 1; goto End;
    };