Using Shamir＇s secret sharing scheme to indi- rectly share the identity-based private key in the form of a pairing group element, we propose an efficient identity-based threshold decryption scheme from pairings and p...Using Shamir＇s secret sharing scheme to indi- rectly share the identity-based private key in the form of a pairing group element, we propose an efficient identity-based threshold decryption scheme from pairings and prove its se- curity in the random oracle model. This new paring-based scheme features a few improvements compared with other schemes in the literature. The two most noticeable features are its efficiency, by drastically reducing the number of pair- ing computations, and the ability it gives the user to share the identity-based private key without requiring any access to a private key generator. With the ability it gives the user to share the identity-based private key, our ID-based threshold decryption （IBTD） scheme, the second of its kind, is signif- icantly more efficient than the first scheme, which was de- veloped by Baek and Zheng, at the expense of a slightly in- creased ciphertext length. In fact, our IBTD scheme tries to use as few bilinear pairings as possible, especially without depending on the suite of Baek-Zheng secret sharing tools based on pairings.展开更多
Double-authentication-preventing signature(DAPS) is a novel signature notion proposed at ESORICS2014. The double-authentication-preventing property means that any pair of signatures on two different messages with the ...Double-authentication-preventing signature(DAPS) is a novel signature notion proposed at ESORICS2014. The double-authentication-preventing property means that any pair of signatures on two different messages with the same subject will result in an immediate collapse of the signature system. A few potential applications of DAPS have been discussed by its inventors, such as providing a kind of self-enforcement to discourage certificate authority(CA) from misbehaving in public key infrastructure and offering CA some cryptographic arguments to resist legal coercion. In this study, we focus on some fundamental issues on DAPS. We propose a new definition,which is slightly weakened but still reasonable and strong enough to capture the DAPS concept. We develop the new notion of invertible chameleon hash functions with key exposure. Then we propose a generic DAPS scheme, which is provably secure if the underlying invertible chameleon hash function with key exposure is secure. We instantiate this general construction to obtain the DAPS schemes respectively based on the well-known assumptions of integer factorization, Rivest-Shamir-Adleman(RSA), and computational Diffie-Hellman(CDH). They are more efficient than previous DAPS schemes. Furthermore, unlike previous constructions, the trusted setup condition is not needed by our DAPS schemes based on RSA and CDH.展开更多
文摘Using Shamir＇s secret sharing scheme to indi- rectly share the identity-based private key in the form of a pairing group element, we propose an efficient identity-based threshold decryption scheme from pairings and prove its se- curity in the random oracle model. This new paring-based scheme features a few improvements compared with other schemes in the literature. The two most noticeable features are its efficiency, by drastically reducing the number of pair- ing computations, and the ability it gives the user to share the identity-based private key without requiring any access to a private key generator. With the ability it gives the user to share the identity-based private key, our ID-based threshold decryption （IBTD） scheme, the second of its kind, is signif- icantly more efficient than the first scheme, which was de- veloped by Baek and Zheng, at the expense of a slightly in- creased ciphertext length. In fact, our IBTD scheme tries to use as few bilinear pairings as possible, especially without depending on the suite of Baek-Zheng secret sharing tools based on pairings.
基金Project supported by the National Natural Science Foundation of China(Nos.61202475,61133014,and 61472114)the Science and Technology Planning Key Project of Shandong Universities,China(No.J18KA326)the Science and Technology Planning Key Project of Guangdong Province,China(No.2016B010124014)
文摘Double-authentication-preventing signature(DAPS) is a novel signature notion proposed at ESORICS2014. The double-authentication-preventing property means that any pair of signatures on two different messages with the same subject will result in an immediate collapse of the signature system. A few potential applications of DAPS have been discussed by its inventors, such as providing a kind of self-enforcement to discourage certificate authority(CA) from misbehaving in public key infrastructure and offering CA some cryptographic arguments to resist legal coercion. In this study, we focus on some fundamental issues on DAPS. We propose a new definition,which is slightly weakened but still reasonable and strong enough to capture the DAPS concept. We develop the new notion of invertible chameleon hash functions with key exposure. Then we propose a generic DAPS scheme, which is provably secure if the underlying invertible chameleon hash function with key exposure is secure. We instantiate this general construction to obtain the DAPS schemes respectively based on the well-known assumptions of integer factorization, Rivest-Shamir-Adleman(RSA), and computational Diffie-Hellman(CDH). They are more efficient than previous DAPS schemes. Furthermore, unlike previous constructions, the trusted setup condition is not needed by our DAPS schemes based on RSA and CDH.
