Generalized signcryption method based on certificate

Abstract

The invention discloses a generalized signcryption method based on a certificate, and belongs to the secret communication field. The method comprises the steps that an authentication center sets system parameters; the user generates a private key and a public key of the user; the authentication center generates a certificate of the user; the sender generates a generalized signcryption ciphertext sigma according to the system parameters, the private key of the sender, the identity and public key of the sender, the identity and public key of the receiver and the message, and sends a result to the receiver; the receiver verifies the correctness of sigma according to the system parameters, the identity and the public key of the receiver, the identity and the public key of the sender and the generalized signcryption ciphertext: if the receiver is correct, the receiver decrypts the message by using the private key and the certificate of the receiver, otherwise, rejection is performed. According to the invention, a sender can realize three functions of encryption, signcryption and signcryption by only using one algorithm and only storing a pair of keys. A cryptosystem based on a certificate is adopted for implementation, the key escrow problem is solved, and the high management cost of the certificate is reduced; and a secure channel is not required between the user and the authentication center.

Description

technical field [0001] The invention belongs to the technical field of information security, and in particular relates to a certificate-based generalized signcryption method. Background technique [0002] Each user in the public key cryptosystem has a pair of keys, while the traditional public key cryptosystem is to determine the user's private key first and then calculate the user's public key, so the public key is a string of meaningless binary strings, which has nothing to do with the user's identity. Therefore, a trusted third party, a Certificate Authority (hereinafter referred to as CA), is required to issue a certificate to bind the user's public key with its identity information. During the entire life cycle of certificates from generation to destruction, the management fee is very expensive, which hinders the widespread use of traditional public key cryptosystems. [0003] In order to reduce the high cost of certificate management, Shamir proposed an identity-based...

AI Technical Summary

Problems solved by technology

[0007] At present, generalized signcryption has achieved very rich research results, but in the aspect of certificate-based generalized signcryption, there are few studies involving

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