Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its ap...Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.展开更多
A ring signature is a variant of normal digital signature and protects the privacy of a specific signer in the sense that a ring signature can be verified,but the signer’s identity can only be traced to a limited set...A ring signature is a variant of normal digital signature and protects the privacy of a specific signer in the sense that a ring signature can be verified,but the signer’s identity can only be traced to a limited set.The concept was further enhanced to threshold setting to distribute signing ability among several signers.Since threshold ring signature was introduced,it was a hard problem whether one can have efficient constructions for it.In this paper,we introduce a new generic construction of threshold ring signature,named GTRS,based on canonical identification of a specific form.Our signature consists of a polynomial(represented by n−t+1 coefficients)and a single response,resulting in significantly shorter threshold ring signatures.Instantiating the generic construction with specific DL-based components,e.g.Schnorr identification and a novel vector argument of knowledge developed in this paper,we obtain GTRS-EC,which is shorter than all existing threshold ring signatures without any trusted setup.展开更多
文摘Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.
基金supported by National Natural Science Foundation of China(Nos.62172404,62172411,61972094,62202458).
文摘A ring signature is a variant of normal digital signature and protects the privacy of a specific signer in the sense that a ring signature can be verified,but the signer’s identity can only be traced to a limited set.The concept was further enhanced to threshold setting to distribute signing ability among several signers.Since threshold ring signature was introduced,it was a hard problem whether one can have efficient constructions for it.In this paper,we introduce a new generic construction of threshold ring signature,named GTRS,based on canonical identification of a specific form.Our signature consists of a polynomial(represented by n−t+1 coefficients)and a single response,resulting in significantly shorter threshold ring signatures.Instantiating the generic construction with specific DL-based components,e.g.Schnorr identification and a novel vector argument of knowledge developed in this paper,we obtain GTRS-EC,which is shorter than all existing threshold ring signatures without any trusted setup.
