Sequence cipher based search encryption method in cloud storage environment

Abstract

The invention relates to a sequence cipher based search encryption method in a cloud storage environment. The sequence cipher based search encryption method in the cloud storage environment comprises the steps of realizing data security search by improving a key stream generation mode in sequence cipher encryption, and carrying out ECB encryption for a searched keyword to form a direct ciphertext; generating a random number by a pseudorandom generator, and generating a key stream by using the random number and the direct ciphertext through a pseudorandom replacement function; and finally carrying out XOR operation for the key stream and the direct ciphertext to obtain a concealed ciphertext, storing the concealed ciphertext at a server and accordingly building a query matching table; when a new search query occurs, firstly calculating a replacement key and then comparing data in the query matching table with the equality relationship among the concealed ciphertext of the current query session, and accordingly confirming the returned query result. The sequence cipher based search encryption method in the cloud storage environment can realize efficient data search of users, can increase the verification efficiency and can guarantee privacy security.

Description

technical field [0001] The invention relates to data security technology in cloud storage, in particular to a search encryption method based on sequence ciphers in a cloud storage environment. Background technique [0002] Sequence cipher is an important branch of symmetric encryption system. It uses key stream generator to generate a key stream to encrypt plaintext in turn. It has the characteristics of simple implementation and fast encryption and decryption processing speed. Nowadays, with the cloud service platform providing more elastic capacity and stronger processing power than traditional servers, enterprises, especially small and medium-sized enterprises, store their data hiddenly to cloud platform providers to reduce costs and improve efficiency. However, outsourced data stored in a third-party cloud platform may be attacked and leaked, and may even be obtained by the cloud platform provider. Moreover, in data search and access, the data pattern is often easily exp...

AI Technical Summary

Problems solved by technology

When searching for a query, the results on the server and the ciphertext are calculated again to see if the original pseudo-random sequence structure can be obtained. In this way, although the encrypted data on the search server can be accessed, the same query request data sent by each After this scheme, only the same ciphertext will be generated. Through the analysis of the data type on the server, the query frequency of a certain requested data can be known. It is easy to determine whether the keyword is a common word by counting the number of times, and the data mode cannot be protected.

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