Cryptographic construction method and system for set member relation determination

• Main Authors: WANG XIN, ZHU YAN, YU RUYUN, GUO RUIQI
• Format: Patent
• Language: English
• Published: 13.05.2015
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; PHYSICS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

The embodiment of the invention discloses a cryptographic construction method and system for set member relation determination, and is applicable to cryptographic expression of set member relation. The method comprises the following steps: converting each element ei in a set U into a random point vi in a cryptographic space; determining the random point vi' corresponding to each element ei' in the set S={ei',...,em'} belongs to and equal to U, and constructing a function fs(x) according to the random point vi'; introducing a random secrete gamma to determine fS(gamma) and a public parameter mpk; processing the fS(gamma) by taking the mpk as an input to generate the cryptographic expression of the set S. The cryptographic expression can realize the set member relation determination: the promise to Rs is constructed according to an aggregate value Rs output by a pole aggregation function of the set S; for the element ei, verifying the promise according to the aggregate value Rs_ output by a zero point aggregation function of the set S_=S\{ei} when ei belongs to S. The method and the system can be used for constructing a group password system meeting broadcast encryption of the set member relation and based on attribute encryption, predicate encryption and the like.