Lightweight Searchable Public-Key Encryption For Cloud-Assisted Wireless Sensor Networks

Cloud-Assisted Wireless Sensor Networks(CWSNs)is a very popular and typical application model at present.It is a concrete manifestation of the deep integration of cloud computing and Internet of Things.In CWSNs scenarios,priority should be given to data privacy protection.The data collected by sensors is mostly private data of individuals or confidential data of enterprises and countries.Whether public clouds or private clouds,they are faced with many security threats.Therefore,from acquisition to storage,to access and processing,these data need comprehensive security protection.Searchable Public-Key Encryption(SPE),as one of basic technologies in terms of cloud data security,is a cryptographic method that can provide secure storage and search for outsourced cloud data.When applying SPE to CWSNs scenarios to protect data security,sensors upload public-key ciphertexts to cloud,which allows the owner of these data securely delegate a keyword search to the cloud and retrieve the intended data while maintaining data confidentiality.However,huge expense is demanded for all existing and semantically secure SPE schemes to generate ciphertexts and search keywords.In view of this situation,this paper proposes a lightweight SPE(LSPE)scheme with semantic security for CWSNs.LSPE reduces a large number of the computation-intensive operations that are required in previous works.To some extent,LSPE has search performance close to that of some efficient searchable symmetric encryption schemes.In addition,LSPE saves considerable time and energy for sensors to generate ciphertexts.In terms of security,the scheme has been proved to be semantically secure in the Random oracle.Finally,we experimentally test the time cost of encryption and the search efficiency of LSPE scheme and compare the results with previous work,which quantitatively verifies the above advantages.