In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed...In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature. However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes. To protect the receiver's benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which can enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim's scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.展开更多
Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as IT...Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as ITTC,etc.,is unsaf e ,inefficient and impracitcal in actual network environment,this paper brings u p a new distributed certification scheme,which although it generates key shares concentratively,it updates key shares distributedly,and so,avoids single-po in t failure like ITTC. It not only enhances robustness with Feldman verification and SSL protocol,but can also change the threshold (t,k) flexibly and robu stly,and so,is much more practical. In this work,the authors implement the prototype sy stem of the new scheme and test and analyze its performance.展开更多
基金Sponsored by the National Natural Science Foudnation of China (Grant No. 60072018,60273082)National Outstanding Youth Science Foundation of China (Grant No. 60225007)
文摘In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature. However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes. To protect the receiver's benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which can enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim's scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.
文摘Distributed certification via threshold cryptography is much more secu re than other ways to protect certification authority (CA) 's private key,and c an tolerate some intrusions. As the original system such as ITTC,etc.,is unsaf e ,inefficient and impracitcal in actual network environment,this paper brings u p a new distributed certification scheme,which although it generates key shares concentratively,it updates key shares distributedly,and so,avoids single-po in t failure like ITTC. It not only enhances robustness with Feldman verification and SSL protocol,but can also change the threshold (t,k) flexibly and robu stly,and so,is much more practical. In this work,the authors implement the prototype sy stem of the new scheme and test and analyze its performance.
