public static UmbralPrivateKey GenRandomPrikey()
{
UmbralPrivateKey k = new UmbralPrivateKey();
k.key = Helper_BigInt.NextBigInteger(k.curve.N.GetBitLength());
return(k);
}
public static UmbralPrivateKey Parse(byte[] data)
{
UmbralPrivateKey k = new UmbralPrivateKey();
BigInteger _key = new BigInteger(data.Reverse().Concat(new byte[] { 0 }).ToArray());
k.key = _key;
return(k);
}
/// <summary>
///
/// </summary>
/// <param name="publickey">公钥</param>
/// <param name="plaintext">原文</param>
/// <param name="capsule">胶囊，一揽子信息</param>
/// <param name="ciphertext">原文</param>
/// <returns></returns>
public static bool Umbral_Encrypt(UmbralPublicKey publickey, byte[] plaintext,
out UmbralCapsule capsule, out byte[] ciphertext)
{
capsule = null;
ciphertext = null;
// g = params.g
var g = publickey.curve.G;
//priv_r = CurveBN.gen_rand(params.curve)
var priv_r = UmbralPrivateKey.GenRandomPrikey();
// pub_r = priv_r * g # type: Any
var pub_r = priv_r.GetPublicKey();
// priv_u = CurveBN.gen_rand(params.curve)
var priv_u = UmbralPrivateKey.GenRandomPrikey();
// pub_u = priv_u * g # type: Any
var pub_u = priv_u.GetPublicKey();
// h = hash_to_curvebn(pub_r, pub_u, params=params)
var h = hash_to_curvebn(pub_r, pub_u);
var s = priv_u.key + priv_r.key * h;
// s = priv_u + (priv_r * h)
//这就是做了个签名嘛 ，pub_r 和 pub_u 按照bytearray连接起来，作为message,并算个hash，再编码成一个bigint h
// s*g= priv_u*g+(priv_r*g*h)=pub_r+pub_u*h
// 相当于用priv_u 和 priv_r双签名，pub_r 和 pub_u 双验签
// if(pub_r+pub_u*h==s) 来判断胶囊和h是否匹配
// shared_key = (priv_r + priv_u) * alice_pubkey.point_key # type: Any
// shared_key 是个point，严格来说是个公钥
ThinNeo.Cryptography.ECC.ECPoint shared_pubkey = publickey.point * (priv_r.key + priv_u.key);
//# Key to be used for symmetric encryption
ThinNeo.Cryptography.ECC.ECPoint key = kdf(shared_pubkey); //kdf 作不作都不影响这个算法,这个kdf函数只是走个过场
capsule = new UmbralCapsule();
capsule.point_e = pub_r.point;
capsule.point_v = pub_u.point;
capsule.bn_sig = s;
//return key, Capsule(point_e = pub_r, point_v = pub_u, bn_sig = s, params=params)
//核心加密逻辑
//sharedkey = publickey * (priv_r+priv_u);
//核心解密逻辑
//sharedkey = privatekey * (pub_r+pub_u) ;
//核心委托重加密逻辑
//d = hash_to_curvebn(precursor,
// bob_pubkey_point,
// dh_point,
// bytes(constants.NON_INTERACTIVE),
// params=params)
//用d作为key，用bob的prikey可以得到这个key
//加密时
//precursor = r.G
//bob_pubkey
//dh_point = r.bob_pubkey
//解密时
//precursor = 传来
//bob_pubkey
//dh_point = bob_prikey.precursor
//令rk = alicekey*(~d)
//则sharedkey = alicekey*(pub_r+pub_u)
//= alicekey * d * (~d) * (pub_r + pub_u);
//= rk * d *(pub_r +pub_u)
//= d * (pub_r*rk + pub_u*rk)
//从publickey -> 转移委托给 publickeybob
//可以得到一个publickeybob - publickey 的点 N
//(h * e_prime) + v_prime:
//所以sharedkey = (publickeybob - N)*(priv_r+priv_u)
// = (privatekeybob.G *(priv_r+priv_u) - N*(priv_r +priv_u)
// sharedkey = privatekeybob*(pub_r+pub_u) - N*priv_r - N*priv_u
//
//
//核心加密逻辑
return(false);
}