最近在学习fisco bcos 库 ， 其中涉及多方计算
gradle 直接下载安装
bcos@cloud-kvm:/opt/gradle$ ls
gradle-6.7.1 gradle-6.7.1-bin.zip
export PATH=$PATH:/usr/local/go/bin:/opt/gradle/gradle-6.7.1/bin

下载
git clone https://github.com/FISCO-BCOS/paillier-lib.git
# 编译
cd paillier-lib/paillierJava && gradle build

FISCO BCOS 2.3版本以预编译合约的形式集成了Paillier方案的密文同态加法接口。要启用同态加密功能需要打开CRYPTO_EXTENSION编译选项，并重新编译源码。同态加密预编译合约地址分配如下：
cmake -DCRYPTO_EXTENSION=ON ..

合约部分
// PaillierPrecompiled.sol
pragma solidity ^0.4.24;
contract PaillierPrecompiled{
function paillierAdd(string cipher1, string cipher2) public constant returns(string);
}

然后可在业务合约中通过地址实例化预编译合约对象以完成同态加接口的调用。
// CallPaillier.sol
pragma solidity ^0.4.24;
import “./PaillierPrecompiled.sol”;

contract CallPaillier {
PaillierPrecompiled paillier;
constructor() public
{
// 实例化PaillierPrecompiled合约
paillier = PaillierPrecompiled(0x5003);
}
function add(string cipher1, string cipher2) public constant
returns(string)
{
return paillier.paillierAdd(cipher1, cipher2);
}
}

string cipher1 = " ..... ";<br />    string cipher2 = "......";<br />    string cipher3 = "0100AF8724B5EEC13B4C5A3396378A8F15FFC54EB0096F4230E301C9EACF8DB59AFB8FAD2C33ED8A180C5F81422A23873E69F2348C19A4BF2DBDC5AE99ADFE8B12C6D5C23A6DC03BBD0FB1EA1A81C77B62E32B7BC1430BEA16AF607455BCD7135C75E886A571567515B089575C58DCCD1A6E7F1C9C36D2E0830200A74ED018C7ED560A5542C6DCAECB8382062AB4CBA95196F9AA92F973DF3AFA25AC4C77567A7461C93C9D0B706990E6DFD0E1593E7E36A0E2042D4FDDE9486B8BB48B24F27313E0210FC28DB38CA3B489135ECE9C3C4B19FDEF4D73FCBB6D33CDC323837AE10A7DFCF4B613686553DAF3EF4836224CAA2DB2A9B6BF41114A4A2007ECE65CC954B72AE8FB8B505E347B30AA9EAD3E933205583D4B842B48B5D1FCE5EF82F95FE405148E14208EFDEE45345232353212C03DBC5FDA9C14550A61957CAADE6B95D17182DD56B6D771BEB8163DCBA9A557BF2561B7931663923985BC2BB02ED1C13262AC4983E600784F9C3FF17E693E22236C7DB364149749EDDF3A1057A4159A7733DACA624367117C0D73FA053C21D8A98B7C945C8FD7B6713A7BA3913D690195597D7448229B192612EF2B4C838A525ED5272C1FBB8B6BAFBE4FA99FD1EABDF59B164B1AE263D7F8ECC59E71E3474E4F9F3E53B73DAB727831968E8CB0875BFF7131E0E2366945E647DD69BA58A01FA7EF20BB72BC486774679714E21CB63E16AF0C9D5DBE3266FD920ACD82036E80A04EE09B48D89283195D093E9760425E785CB9A7472E81C2CF079BB92EC5180002C5A134BA29E26EB17C1D4662F0B888D729F5BB57B2F288BC39A855BC1F509F8165FE434907F484476CFBC209A9C8943441A90186B64CB1113D04BD09CD9161B672E0CE54EE450932F6CC3D45D0E5E035322607A40A829C67CC81E09BC062BB007594B68BB85A4F8934739B8D5FF432EE57E840E1B7D66F721FC0BD6BF644A40C17CEF0ACE9F0EC98CD2D0EA81472A161A72DD1349FAFCA1C32D15F6AF0571BB4288DD479264D1A8DE5B318A06A3C013411D5F5037A5823404D30C542F8F809EA624CDBCD0332E6D28106484B2F4EC754D0";

使用0x5003直接调用 0x5003 对应的接口是 PaillierPrecompiled
./console.sh call PaillierPrecompiled.sol 0x5003 paillierAdd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

cipher1 + cipher2 = cipher3

同态加密可分为全同态加密（FHE，Fully Homomorphic Encryption）和半同态加密（SWHE，Somewhat Homomorphic Encryption）。

FHE顾名思义就是支持任意给定的f()函数，不过由于计算开销极大，目前学术界还没有一个实用型的FHE方案；SWHE只支持一些特定的f()函数，例如加法或者乘法等，由于开销小，在工业界尤其是云计算领域已有不少的应用。

openssl 命令行
openssl genrsa -out prikey.pem 2048 产生私钥
openssl rsa -in prikey.pem -pubout -out pubkey.pem 产生公钥
openssl rsautl -encrypt -in ./add/add1.txt -inkey pubkey.pem -pubin -out ./add/add1.en 加密
openssl rsautl -decrypt -in ./add/add1.en -inkey prikey.pem -out hello.de 解密
xxd -ps add1.en 十六进制显示文件

隐私计算
https://github.com/clearmatics/zeth
参考
https://fisco-bcos-documentation.readthedocs.io/zh_CN/latest/docs/articles/3_features/38_privacy/index.html