Non-interactive Public-Key Cryptography

Abstract

An identity-based non-interactive public key distribution system is presented that is based on a novel trapdoor one-way function allowing a trusted authority to compute the discrete logarithm of a given number modulo a publicly known composite number rn while this is infeasible for an adversary not knowing the factorization of m. Without interaction with a key distribution center or with the recipient of a given message a user can generate a mutual secure cipher key based solely on the recipient's identity and his own secret key and send the message, encrypted with the generated cipher key using a conventional cipher, over an insecure channel to the recipient. Unlike in previously proposed identity-based systems, no public keys, certificates for public keys or other information need to be exchanged and thus the system is suitable for many applications such as electronic mail that do not allow for interaction. 'A more detailed version of this paper has been submitted to the IEEE 'Jlansactions on Information Theory. *Work performed while consulting for Omnisec AG, Switzerland, prior to joining Princeton Univereity.

Another look at non-standard discrete log and Diffie-Hellman problems

“…The obstruction is that the DLP does not have any obvious "trapdoor", and so it is unclear how to get a component of a protocol to behave as a DLP oracle. Many years ago Maurer and Yacobi [30] used a trapdoor version of DLP to set up an ID-based encryption system in which the trusted authority returned the discrete log of Alice's identification as her secret key. However, they had to assume that the group order remained secret, and for this reason the security of their system would disappear if an attacker were allowed to query the trusted authority with any number of her choice (rather than with an actual identification number verified by a supporting document).…”

Applied cryptography: Protocols, algorithms, and source code in C

“…For details, algorithms, and cryptanalysis, see [191,1422,891,1022,1515,1202,1196,908,692,674,1131,1023,1516,1536,1544,63,1210,314,313,1545,1539,1543,933,1517,748,1228]. An algorithm that does not rely on any random numbers is [1035]. The system discussed in [1546,1547,1507] is insecure against a chosen-publickey attack; so is the system proposed as NIKS-TAS [1542,1540,1541,993,375,1538].…”

A Secure and an Efficient ID-based Multi-Proxy Multi-Signature Scheme from Bilinear Pairings

“…In 1984 Shamir [1] proposed ID-based encryption and signature schemes to simplify key management procedures in certificate-based public key setting. Since then, many ID-based encryption and signature schemes [13,14,15,3] have been proposed. The main idea of ID-based cryptosystems is that the identity information of each user works as his/her public key, in other words, the users public key can be calculated directly from his/her identity rather than being extracted from a certificate issued by a certificate authority (CA).…”