Design And Analysis Of Certificateless Public Key Encryption Scheme In Cloud

Since its introduction,cloud computing has attracted the attention of many Internet companies and experts,and has developed tremendously.Today,cloud computing has been used in many scenarios,such as finance,healthcare,the Internet of things and so on.It permeates people's life and work comprehensively.With the development of cloud computing,cloud storage has been also widely used.Cloud storage can meet users' needs for storing massive amounts of data.Because cloud storage also has the characteristics of automatic management,flexible expansion,and low operating costs,it has been used by more and more enterprises and individuals.So its security has also received much attention.Cloud storage security is mainly reflected in whether the data stored by users in the cloud will be obtained by illegal users.Encrypting user data is the basic means used to protect user privacy.In order to solve the problem of user's key security and searching encrypted files by keywords on the cloud server,we comprehensively consider the advantages and disadvantages of different public key cryptography and then propose a certificateless public key encryption scheme and a certificateless public key encryption scheme with keyword search.The main research contents of this article as follows:(1)We propose a certificateless public key encryption scheme(CL-PKE).Under the random oracle model,our scheme has IND-CCA2 security,which meas it meets the ciphertext indistinguishability under adaptive selection ciphertext attack.We first give the security model and its specific scheme structure according to the formal definition.Compared with other schemes,this scheme has greatly improved the calculation cost and communication cost.We also give the application case of the scheme in the cloud computing environment.This scheme is implemented based on the PBC library finally.(2)We also propose a certificateless public key encryption scheme with keyword search(CL-PKES)based on CL-PKE.We give a formal definition and a security model.Then we give a concrete scheme structure based on the formal definition.We also prove that the scheme has IND-CKA security according to the security model.We compare our scheme with other similar schemes and implement it based on the PBC library to prove its advantage in terms of calculation cost and communication cost.Finally,we give an application case in the cloud environment.Both of the above schemes are the applications of certificateless public key cryptography in the cloud computing environment.Compared with other similar schemes,they have higher efficiency and lower computing cost.Therefore,they have significance for ensuring the security of cloud storage data.