Study On Provably Secure Signcryption In The Standard Model

In today’s society, people usually need network to deliver a variety of usefulinformation, which resulted in a lot of information filled in the network, but alsoprovided rich diets to criminals. This leads to the cryptography technology, andencryption and digital signatures is very important to cryptograpty technology.Any illegl can be prevented access to plaintext message from the ciphertextthrough encryption technology. And the digital signature technology enables therecipient to know the real sender.Signcryption technology is a new cryptography, which combined by thedigital signature and encryption technology. Signcryption has simple algorithmand low efficiency. The signcryption technology has a wide range of applications.Public key cryptography need a provable security theory to prove that proposedscheme is secure.The provable security theory is one of the hotspot studies.Today, many schemes to be proved safty in random oracle model, need studied asigncryption scheme which can be proved safty in the standard model.This paper studied three kinds of signcryption scheme, including identity-based signcryption, multi-signcryption, and certificatless signcryption. Theseprograms have proven to be safe in the standard model. Research results include:design of a identity-based signcryption scheme in the standard model; proposedof a identity-based signcryption scheme with multiple signcrypers in the standardmodel, which improve the efficiency of the algorithm by reducing the bilinearpairings; studied of a more efficient certificatless signcryption scheme in thestandard mode, and gived a better proof. The secutity of previous two programscan be attributed to the DBDH and CDH problem, and the last security of thescheme can be attributed q-ABDHE and q-SDH problem.