Search Over Encrypted Data On The Cloud—A General Framework,the Properties And Security Risks

With the popularity of the Internet and cloud storage services,when the data owner stores the data in the cloud in the form of ciphertext,search over encrypted data on the cloud is a problem that needs to be solved.At present,most of the research focus on keyword-search,but with the needs of different scenarios,keyword-search is far from satisfying the search needs of users.In addition,because search over encrypted data itself will inevitably leak at least one type of information between plaintexts to the server,when many researchers try to construct a scheme for a new search method,they may ignore that the scheme will have different degrees of security risks when the leaked information change.The attack caused by this security risk can not depend on the specific algorithm of the scheme,but depends on the degree of "strength" of the information itself.Ignoring this problem can lead to even the most perfect construction scheme,which may still has great security risks.Therefore,based on the above two problems that need to be solved,this paper starts the research on encrypted data search on the cloud.First,the authors give a general definition of a framework for searching over encrypted data on the cloud.This paper not only gives the relation of this definition to other existing cryptographic concepts,but also explains how some existing cryptosystems are a special case of the definition given in this paper.Then,we analyzed some inherent properties possessed by the framework.It is worth noting that the method of equivalence class partition greatly helps and simplifies our analysis.Almost all properties in this paper are established on the basis of equivalence class that this paper define.On the basis of the definition of the framework and its properties,this paper focus on the security risks under the framework.This paper not only gives a variety of attack models,but also find a way to quantitative analysis the influence from the information leakage to the upper bound of security.The attacks proposed in this paper do not depend on specific algorithms.Therefore,these attacks are applicable to all encrypted data search schemes that fit our framework.However,our general framework includes the construction of most encrypted data search schemes.So,these attack are effective on most existing and future schemes that fit our framework,which has very high guiding significance.Therefore,this article points out that it is very important to analyze the influence from the information leakage to the security before we try to construct a specific scheme of a new search method over encrypted data.When it comes to this,our general definition,properties,and security risk analysis of this paper can give a comprehensive reference and guidance.