Recently, proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been pro-posed, there a...Recently, proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been pro-posed, there are only two identity-based proxy ring signature schemes have been proposed until now, i. e., Cheng＇s scheme and Lang＇s scheme. It＇s unlucky that the two identity-based proxy ring signature schemes are unfeasible. This paper points out the reasons why the two identity-based proxy ring signature schemes are unfeasible. In order to design feasible and efficient identity-based proxy ring signature schemes from bilinear pairings, we have to search for other methods.展开更多
Signcryption is a public key cryptographic method that achieves unforgeability and confidentiality simultaneously with significantly smaller overhead than that required by ＂digital signature followed by public key en...Signcryption is a public key cryptographic method that achieves unforgeability and confidentiality simultaneously with significantly smaller overhead than that required by ＂digital signature followed by public key encryption＂. It does this by signing and encr.ypting a message in a single step. An aggregate signcryption scheme allows individual signcryption ciphertexts intended for the same recipi- ent to be aggregated into a single （shorter） combined ciphertext without losing any of the security guarantees. We present an aggregate signcryption scheme in the identity-based setting using multilinear maps, and provide a proof of security in the standard model. To the best of our knowledge, our new scheme is the first aggregate signcryption scheme that is secure in the standard model.展开更多
基金Supported by the National Natural Science Foundation of China （No.60432040）.
文摘Recently, proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been pro-posed, there are only two identity-based proxy ring signature schemes have been proposed until now, i. e., Cheng＇s scheme and Lang＇s scheme. It＇s unlucky that the two identity-based proxy ring signature schemes are unfeasible. This paper points out the reasons why the two identity-based proxy ring signature schemes are unfeasible. In order to design feasible and efficient identity-based proxy ring signature schemes from bilinear pairings, we have to search for other methods.
文摘Signcryption is a public key cryptographic method that achieves unforgeability and confidentiality simultaneously with significantly smaller overhead than that required by ＂digital signature followed by public key encryption＂. It does this by signing and encr.ypting a message in a single step. An aggregate signcryption scheme allows individual signcryption ciphertexts intended for the same recipi- ent to be aggregated into a single （shorter） combined ciphertext without losing any of the security guarantees. We present an aggregate signcryption scheme in the identity-based setting using multilinear maps, and provide a proof of security in the standard model. To the best of our knowledge, our new scheme is the first aggregate signcryption scheme that is secure in the standard model.
