2 results about "Pseudorandom permutation" patented technology

The invention relates to the technical field of information security, in particular to a searchable encryption method and system based on an sm4 algorithm, and the method comprises the steps: key generation: generating a first key and a second key; index construction: constructing an inverted index dictionary based on the data set; key word encryption: carrying out encryption replacement on key words in the reverse index by using the first key; node encryption and filling: encrypting the nodes in the inverted record tables by using the second key, and filling all the inverted record tables to be equal in length; trap door generation: respectively executing first key encryption and second key encryption on the query keyword to generate a search trap door; and searching and matching: carrying out matching retrieval in the encrypted inverted index by utilizing the search trap door, and outputting a corresponding encrypted document identifier. According to the method, through collaborative design of SM4 double-key encryption, pseudo-random permutation, equal-length filling and a trap door retrieval mechanism, high-security storage of cloud data and efficient retrieval under the ciphertext condition are achieved.

This application discloses a file processing method, an electronic device, and a storage medium. The file processing method includes: determining a first identifier vector for a file based on its position in a file set; generating a first storage location for storing the first identifier vector based on a hash function and the file's feature vector; determining a second identifier vector based on the hash table corresponding to the hash function and the first identifier vector; and storing the second identifier vector in a second storage location obtained by performing a pseudo-random permutation on the first storage location. The second storage location is used to locate the first storage location corresponding to the feature vector of the file to be searched when searching for a file. Thus, based on the second storage location and the position of the file to be searched in the file set, the corresponding file can be found without requiring the user to provide precise keywords for the search, thereby improving file search efficiency.