Abstract: The present invention mainly relates to the field of information technology, and specifically to a method and system for cryptographic attribute-based access control supporting dynamic rules. In the system, the protected object is stored in an encrypted form, only the access request satisfying the access policy in attribute-based access control can be authorized to decrypt the object, which ensures that the access to data in an unsecure environment can be authorized according to a security policy, and supports dynamic policy and real-time authorization of attributes.

Abstract: The present invention mainly relates to the field of information technology, and specifically to a method and system for cryptographic attribute-based access control supporting dynamic rules. In the system, the protected object is stored in an encrypted form, only the access request satisfying the access policy in attribute-based access control can be authorized to decrypt the object, which ensures that the access to data in an unsecure environment can be authorized according to a security policy, and supports dynamic policy and real-time authorization of attributes.

Abstract: A method and system for group-oriented encryption and decryption that supports the implementation of the designation and revocation functions of decryption users in a large-scale group.

Abstract: A method and system for group-oriented encryption and decryption that supports the implementation of the designation and revocation functions of decryption users in a large-scale group.

Abstract: A cryptographic decision-making of set membership is a method or system which make a secure decision-making for positive membership e?S or negative membership e?S in an unforgeable and non-repudiation way for any element e and a set S. The proposed method of the present invention comprises: acquire a set U={e1, . . . , en} and map each element ei in U into a random point vi in a cryptography space; acquire a set S={e?1, . . . , e?m}?U, determine a random point v?i corresponding to each element e?i in the set S, and construct a function ƒS(x) according to all random points v?i; introduce a random secret ? to generate ƒS(?) by using the function ƒS(x), and produce a public parameter mpk according to the random secret ?; and generate the cryptographic representation of set S by using the function ƒS(?) and the public parameter mpk.