Fuzzy retrieval of encrypted data by multi-purpose data-structures

The growing amount of information that has arisen from emerging technologies has caused organizations to face challenges in maintaining and managing their information. Expanding hardware, human resources, outsourcing data management, and maintenance an external organization in the form of cloud storage services, are two common approaches to overcome these challenges; The first approach costs of the organization is only a temporary solution. By contrast, the cloud storage services approach allows the organization to pay only a small fee for the space actually in use (rather than the total reserved capacity) and always has access to the data and management tools with the most up-to-date mechanisms available. Despite the benefits of cloud storage services, security challenges arise because the organizationchr('39')s data is stored and managed outside of the most important organization’s supervision. One challenge is confidentiality protection of outsourced data. Data encryption before outsourcing can overcome this challenge, but common encryption schemes may fail to support various functionalities in the cloud storage service. One of the most widely used functionalities in cloud storage services is secure keyword search on the encrypted documents collection. Searchable encryption schemes, enable users to securely search over encrypted data. Based on the users’ needs, derivatives of this functionality have recently been considered by researchers. One of these derivatives is ranked search that allows the server to extract results based on their similarity to the searched keyword. This functionality reduces the communication overheads between the cloud server and the owner organization, as well as the response time for the search. In this paper, we focus on the ranked symmetric searchable encryption schemes. In this regard, we review structures proposed in the symmetric searchable encryption schemes, and show that these two data structures have capabilities beyond their original design goal. More precisely, we show that by making the data structures, it is possible to support secure ranked search efficiently. In addition, by small changes on these data, we present two ranked symmetric searchable encryption schemes for single keyword search and Boolean structures which introduced-keyword search based on the data.