A Study on Searchable Encryption System against Chosen-Ciphertext Attack

Abstract

The cloud computing service with which they may outsource the data storage and process them with various terminals at any time any where is getting vitalized as the network and computing technology develops. Especially, DaaS(Database as a Service) is widely used out of cloud computing services. However, it needs to encrypt the database stored in outsourcing storage because there is a security problem that the database stored in the server could be read by hackers and unethical server administrator without prior consent of the owner if the individual’s sensitive information such as its physical information is stored without being encrypted in the database. However, entrusting the data storage makes no sense if the owner has to search the data by decrypting them after downloading all encrypted data into his terminals in order to search his data in safe with the existing encryption algorithm. A Searchable Encryption System has currently been appeared in order to solve such a problem. But, the existing searchable encryption system has the same typed trapdoors which are created to search the same keywords because numerous search queries are transmitted to the entrusted storage center and the administrator of the center shall be able to analogize the keywords and learn which data the user stores and search through such queries. Thus, this paper proposes a Searchable Encryption System using the one time trapdoor which prevents the unethical server administrator from analogizing the contents of search and data through search queries by creating the different trapdoor whenever the same user searches the same keywords.