关键词: 可搜索加密, 伪随机函数, 穿刺伪随机函数, 前向安全, 后向安全

Abstract: Dynamic searchable encryption has attracted wide attention due to its ability to add, delete, and search data on cloud servers. Existing dynamic searchable encryption schemes are usually constructed using highly secure cryptographic primitives, and multiple bilinear pairing operations need to be calculated when searching for the scheme. In view of the large computational overhead of dynamic searchable encryption schemes when searching on server, a puncture pseudorandom function was introduced into dynamic searchable encryption, and a dynamic searchable encryption scheme based on a Puncture PseudoRandom Function (PPRF) was designed and proposed. The file identifier does not need to be encrypted using symmetric encryption algorithms, and it is also not necessary to decrypt the ciphertext to obtain the file identifier during server searches; the client and server can complete the data search with just one interaction. The scheme marks the key when deleting keywords, uses the marked key to calculate the punctured pseudo-random function during the search, and implements backward security with a forward-secure scheme, ensuring security while improving search efficiency. According to the security model of the dynamic searchable encryption scheme, the security of the scheme was proved. The simulation experiment results show that compared with other schemes such as RObust Searchable Encryption (ROSE) scheme built on Key Updateable Pseudo-Random Function (KUPRF), Janus++ scheme built on Symmetric Puncture Encryption (SPE), and Aura scheme built on symmetric revocable encryption (SRE), the average search time of each keyword is reduced by 17%, 64%, and 57% respectively. The proposed scheme is effective and feasible, which effectively reduces the search cost of server, improves the search efficiency of the scheme, and increases the practicality of the scheme.

Key words: searchable encryption, pseudo-random function, puncture pseudorandom function, forward security, backward security