We introduce the abstract framework of decentralized smart contracts system with balance and transaction amount hiding property over account-model blockchain. To build a concrete system with such properties, we utilize a homomorphic public-key encryption scheme and construct a highly efficient non-interactive zero knowledge (NIZK) argument based upon the encryption scheme to ensure the validity of the transactions. Our NIZK scheme is perfect zero knowledge in the common reference string model, while its soundness holds in the random oracle model. Compared to previous similar constructions, our proposed NIZK argument dramatically improves the time efficiency in generating a proof, at the cost of relatively longer proof size.

中文翻译：

---

一种基于账户模型区块链的高效隐私保护交易 NIZK 方案


我们介绍了去中心化智能合约系统的抽象框架，其余额和交易金额隐藏在账户模型区块链上。为了构建具有此类属性的具体系统，我们利用同态公钥加密方案，并基于该加密方案构建高效的非交互式零知识（NIZK）论证，以确保交易的有效性。我们的 NIZK 方案在公共参考串模型中是完美的零知识，而其可靠性在随机预言模型中成立。与之前的类似结构相比，我们提出的 NIZK 论证极大地提高了生成证明的时间效率，但代价是证明尺寸相对较长。