Gaybullaev Turabek, Kwon Hee-Yong, Kim Taesic, Lee Mun-Kyu
Department of Electrical and Computer Engineering, Inha University, Incheon 22212, Korea.
Department of Electrical Engineering and Computer Science, Texas A&M University, Kingsville, TX 78363, USA.
Sensors (Basel). 2021 Mar 12;21(6):2024. doi: 10.3390/s21062024.
The rapidly increasing expansion of distributed energy resources (DER), such as renewable energy systems and energy storage systems into the electric power system and the integration of advanced information and communication technologies enable DER owners to participate in the electricity market for grid services. For more efficient and reliable power system operation, the concept of peer-to-peer (P2P) energy trading has recently been proposed. The adoption of blockchain technology in P2P energy trading has been considered to be the most promising solution enabling secure smart contracts between prosumers and users. However, privacy concerns arise because the sensitive data and transaction records of the participants, i.e., the prosumers and the distribution system operator (DSO), become available to the blockchain nodes. Many efforts have been made to resolve this issue. A recent breakthrough in a P2P energy trading system on an Ethereum blockchain is that all bid values are encrypted using functional encryption and peer matching for trading is performed securely on these encrypted bids. Their protocol is based on a method that encodes integers to vectors and an algorithm that securely compares the ciphertexts of these vectors. However, the comparison method is not very efficient in terms of the range of possible bid values because the amount of computation grows linearly according to the size of this range. This paper addresses this challenge by proposing a new bid encoding algorithm called dual binary encoding, which dramatically reduces the amount of computation as it is only proportional to the square of the logarithm of the size of the encoding range. Moreover, we propose a practical mechanism for rebidding the remaining amount caused when the amounts from the two matching peers are not equal. Finally, the feasibility of the proposed method is evaluated by using a virtual energy trade testbed and a private Ethereum blockchain platform.
分布式能源资源（DER），如可再生能源系统和储能系统，迅速扩展并融入电力系统，同时先进信息通信技术的集成使DER所有者能够参与电网服务的电力市场。为实现更高效、可靠的电力系统运行，最近提出了对等（P2P）能源交易的概念。在P2P能源交易中采用区块链技术被认为是实现生产者与用户之间安全智能合约的最具前景的解决方案。然而，由于参与者（即生产者和配电系统运营商（DSO））的敏感数据和交易记录会被区块链节点获取，引发了隐私问题。人们已做出诸多努力来解决这一问题。以太坊区块链上的P2P能源交易系统最近的一项突破是，所有投标值都使用功能加密进行加密，并且基于这些加密投标安全地执行交易的对等匹配。他们的协议基于一种将整数编码为向量的方法以及一种安全比较这些向量密文的算法。然而，就可能的投标值范围而言，该比较方法效率不高，因为计算量会根据此范围的大小线性增长。本文通过提出一种名为双二进制编码的新投标编码算法来应对这一挑战，该算法显著减少了计算量，因为它仅与编码范围大小的对数的平方成正比。此外，我们提出了一种实用机制，用于对两个匹配对等方的金额不相等时产生的剩余金额进行重新投标。最后，通过使用虚拟能源交易测试平台和私有以太坊区块链平台评估了所提方法的可行性。
