具有隐私保护的细粒度智能家居远程数据安全更新方案

针对现存智能家居软件更新方案中存在的粗粒度访问控制、单点服务失效、用户解密效率低下等问题，该文提出一种具有隐私保护的细粒度智能家居远程数据安全更新方案。该方案通过属性基加密技术实现了细粒度访问控制，并结合区块链和星际文件系统(IPFS)技术对数据进行存储。通过对访问策略进行隐藏，构造出一种策略隐藏的密文策略基于属性加密(CP-ABE)算法，进一步保护了用户的隐私。此外，通过设计面向轻量级用户的外包解密算法，所提方案有效减轻了轻量级用户的计算负担，并结合区块链和智能合约技术实现了外包解密过程的公平支付。最后，基于判定的双线性迪菲赫尔曼 (DBDH)假设，证明了所提方案是选择明文攻击下的不可区分 (IND-CPA)安全的。仿真实验结果表明，所提方案与现有方案相比终端用户解密成本和通信开销明显降低。

Fine-grained Remote Data Security Update Scheme for Smart Home with Privacy Protection

In order to address these problems of coarse-grained access control, single point of service failure and low user decryption efficiency in existing smart home firmware update schemes, a fine-grained remote data security update scheme for smart home with privacy protection is proposed. The scheme realizes fine-grained access control through attribute-based encryption technology, and combines blockchain and Inter Planetary File System (IPFS) technology to store data. This scheme protects further user’s privacy by hiding access policies. And the Ciphertext Policy Attribute-Based Encryption (CP-ABE) is proposed. In addition, the outsourcing decryption algorithm for lightweight users is designed to reduce the computing burden of lightweight users effectively, and the fair payment in the outsourcing decryption process is realized by combining blockchain and smart contract technology. Finally, based on Decisional Bilinear Diffie-Hellman (DBDH) assumption, the proposed scheme is proved to be INDistinguishability under Chosen-Plaintext Attack (IND-CPA) security. The experimental results show that the proposed scheme reduces significantly the cost of terminal user decryption compared and communication overhead with existing schemes.