Differentiated Searchable Public Key Encryption Based On Attribute-multiple Keyword Vectors

With the high-speed development of cloud computing, distributed computing and storage capacity of the cloud computing, and comprehensive consideration to its economical efficiency and convenience, currently, more and more enterprises and users in order to save the local computation and storage costs, are willing to outsource their data to a third party platform for the public cloud computing and storage. But because the enterprise or the user is not fully trusted third party cloud platform, in order to guarantee the data security and privacy of users, many companies or the user can choose the data in the form of a cipher text stored in the cloud server. And how in the cloud on the cipher text fast search more resource that users need through keyword is the focus of this paper.Existing search public key encryption is mostly based on composite order bilinear pairings computation, low efficiency and slow, and many are for a single user application scenario of a single keyword search. The access control technology is also a coarse-grained and not flexible with a single security encryption service mode, and in the case of a large amount of data and resource constraints, it will produce inadequate computing resources or waste phenomenon.In this paper, first of all, It studies the properties of the encryption cipher text strategy which has the characteristics of fine-grained access control strategy, and combines the current search deficiencies existing in the encryption scheme. Several aspects of the research work and innovation are as follows:1) Existing attribute vector encryption algorithm is improved, based on the attribute- encrypted cryptograph strategy which can search keyword vector model of public key encryption, ensuring users search more demand. And at the same time, it also can adapt many users search application scenarios to realize the function of data sharing with other users.2) Structure composed of multiple attributes and keyword vector is proposed in addition with the wildcard product which can match without the access condition attributes. And it uses the prime order bilinear pairings computation to greatly save the consumption of computation time and storage space.3) Considering the limited resources, when the cloud had left in the original system model, it tends to join the varies levels to the importance of security encryption service according to the data owner's identity information and the importance of files that are uploaded and shared, which saves the computing resources and improve efficiency.Based on the Java class library of j PBC system implementation of the model, comparing with similar algorithms and checking the each level security encryption service mode, its effect is good, and it can realize the strict access control and make multi-user share fast search mechanism. And finally its application in the medical treatment of new-style mobile cloud platform on the scene.