A digital signature scheme secure against adaptive chosen-message attacks
SIAM Journal on Computing - Special issue on cryptography
Random oracles are practical: a paradigm for designing efficient protocols
CCS '93 Proceedings of the 1st ACM conference on Computer and communications security
Communications of the ACM
A method for obtaining digital signatures and public-key cryptosystems
Communications of the ACM
Flaws in Applying Proof Methodologies to Signature Schemes
CRYPTO '02 Proceedings of the 22nd Annual International Cryptology Conference on Advances in Cryptology
Digital Signcryption or How to Achieve Cost(Signature & Encryption)
CRYPTO '97 Proceedings of the 17th Annual International Cryptology Conference on Advances in Cryptology
Relations Among Notions of Security for Public-Key Encryption Schemes
CRYPTO '98 Proceedings of the 18th Annual International Cryptology Conference on Advances in Cryptology
On the Security of Joint Signature and Encryption
EUROCRYPT '02 Proceedings of the International Conference on the Theory and Applications of Cryptographic Techniques: Advances in Cryptology
Parallel authentication and public-key encryption
ACISP'03 Proceedings of the 8th Australasian conference on Information security and privacy
Parallel authentication and public-key encryption
ACISP'03 Proceedings of the 8th Australasian conference on Information security and privacy
Identity based public verifiable signcryption scheme
ProvSec'10 Proceedings of the 4th international conference on Provable security
Efficient short signcryption scheme with public verifiability
Inscrypt'06 Proceedings of the Second SKLOIS conference on Information Security and Cryptology
Improved signcryption from q-Diffie-Hellman problems
SCN'04 Proceedings of the 4th international conference on Security in Communication Networks
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A parallel authentication and public-key encryption is introduced and exemplified on joint encryption and signing which compares favorably with sequential Encrypt-then-Sign (EtS) or Sign-then-Encrypt (StE) schemes as far as both efficiency and security are concerned. A security model for signcryption, and thus joint encryption and signing, has been recently defined which considers possible attacks and security goals. Such a scheme is considered secure if the encryption part guarantees indistinguishability and the signature part prevents existential forgeries, for outsider but also insider adversaries. We propose two schemes of parallel signcryption, which are efficient alternative to Commit-then-Sign-and-Encrypt (CtE&S). They are both provably secure in the random oracle model. The first one, called generic parallel encrypt and sign, is secure if the encryption scheme is semantically secure against chosen-ciphertext attacks and the signature scheme prevents existential forgeries against random-message attacks. The second scheme, called optimal parallel encrypt and sign, applies random oracles similar to the OAEP technique in order to achieve security using encryption and signature components with very weak security requirements - encryption is expected to be one-way under chosen-plaintext attacks while signature needs to be secure against universal forgeries under random-plaintext attack, that is actually the case for both the plain-RSA encryption and signature under the usual RSA assumption. Both proposals are generic in the sense that any suitable encryption and signature schemes (i.e. which simply achieve required security) can be used. Furthermore they allow both parallel encryption and signing, as well as parallel decryption and verification. Properties of parallel encrypt and sign schemes are considered and a new security standard for parallel signcryption is proposed.