Lightweight Searchable Encryption with Small Clients on Edge Cloud

In view of the limited storage and computing power of the client and the high delay of interaction with the cloud platform in public key searchable encryption, a new public key searchable encryption scheme SE-EPOMFC based on edge cloud network is proposed. The scheme adopts a multi cloud multi edge node architecture. By delegating the task of generating searchable ciphertext, trapdoor and general keyword set from the client to the edge node, the storage and computing overhead of the client is reduced. The edge network caches the frequently searched hot data, and the client can search on the edge network, so as to reduce the traffic load of the backbone network. At the same time, the response speed of the system is improved. A filtering algorithm based on partial homomorphic encryption is designed to filter completely mismatched tasks, which reduces the communication overhead between distributed systems and saves storage space for cloud services. The filtering algorithm can be calculated in the ciphertext state, which proves that it is safe under the collusion attack of semi trusted edge cloud nodes. In addition, the distributed two trapdoor public key cryptosystem is used to divide the keys for multiple nodes. Through the subset decisionmaking mechanism, the relationship between keywords is represented by binary strings to realize the search of multiple keywords. The simulation results show that the communication time of se-epomfc is saved by 25.46% in the case of task set matching degree II and 62.21% in the case of task set matching degree I.