The sensing-as-a-service (SaaS) model has been explored to address the challenge of intractability of managing a large number of sensors faced by future smart cities. However, how to effectively share sensor data without compromising confidentiality, privacy protection, and fair trading without third parties is one of critical issues that must be solved in the SaaS in smart cities. While blockchain shows promise in solving these issues, the existing blockchain-based data sharing (BBDS) systems are difficult to apply to SaaS in smart cities because of many unresolved issues such as requiring a customized blockchain, huge storage, communication and computation costs, and dependence on a third party to achieve fair trading. We propose a BBDS system model with its security requirements before we present a concrete construction by combining -protocol, Paillier encryption scheme, and any secure symmetrical encryption and signature schemes. To demonstrate the utility of our proposed BBDS system, we present a security analysis and compare our system with other solutions. We implement the prototype in Remix to analyze the gas cost, and we conduct experiments to evaluate the communication and computation costs of the BBDS system using symmetric encryption (advanced encryption standard (AES)) and a signature scheme (elliptic curve digital signature algorithm (ECDSA)).

中文翻译：

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基于区块链的智能城市感知即服务数据共享系统

已经探索了传感即服务 (SaaS) 模型，以解决未来智慧城市面临的管理大量传感器的棘手挑战。然而，如何在不损害机密性、隐私保护和公平交易的情况下，在没有第三方的情况下有效共享传感器数据，是智慧城市SaaS必须解决的关键问题之一。虽然区块链有望解决这些问题，但现有的基于区块链的数据共享 (BBDS) 系统难以应用于智慧城市的 SaaS，因为需要定制区块链、巨大的存储、通信和计算成本等许多未解决的问题，以及依赖第三方来实现公平交易。我们提出了一个 BBDS 系统模型及其安全要求，然后我们通过结合 -协议、Paillier 加密方案以及任何安全的对称加密和签名方案。为了展示我们提出的 BBDS 系统的实用性，我们进行了安全分析并将我们的系统与其他解决方案进行了比较。我们在 Remix 中实现原型以分析 gas 成本，并进行实验以评估使用对称加密（高级加密标准（AES））和签名方案（椭圆曲线数字签名算法（ECDSA）的 BBDS 系统的通信和计算成本））。