A smart contracts-based searchable encryption scheme with forward privacy

As an important link of the Internet of Things, wireless sensor network has great potential in industry, agriculture and daily use of residents. To ensure cloud data security, data is encrypted before being uploaded to the cloud. However, how to ensure the searchability of ciphertext in cloud is challenging. To solve the above problems, a searchable encryption scheme for sensor networks is proposed. The sensor node collects the data, encrypts it and uploads it to the smart contract after collecting the data from the local gateway. In this scheme, the concept of version information is introduced to authenticate ciphertext version so as to realize access control of trap gates of different versions. In order to avoid data leakage caused by the information storage center, the searchable encryption technology is combined with the block chain technology, and the smart contract is used as the data storage center, so as to ensure efficient ciphertext retrieval and eliminate malicious behavior on the server side. Through security analysis, it is proved that the scheme satisfies ciphertext indistinguishability and forward security based on DBDH hard problems. Experimental efficiency analysis shows that the scheme has certain advantages in computational efficiency.