Signcryption Algorithm Based On Certificateless System And Random Oracle Model

The information network has been developing rapidly,and the security of the network has been seriously questioned,so ensuring the security of the network environment is a matter of concern to all people.Cryptography technology is an important measure to realize network security communication,than the traditional method is to sign and encrypt,and the present method is the integration of signature and encryption.Certificateless public key cryptosystem(CL-PKC)not only reduces the complex operation of certificate management,but also avoids the security defects of key escrow.Aggregated signcryption not only ensures the confidentiality and authentication of information transmission,but also reduces the power consumption of information transmission,so it applies to many to one mode applied in large-scale distributed communication;In order to meet the multi-receiver and multi-message sending requirements of the sender in the broadcast communication environment,so the multi-message signcryption scheme of the certificate free multiple receiver is proposed.This thesis studies the aggregation signcryption and multi-receivers based on the certificateless system,then the results are as follows:(1)Most of the aggregated signcryption schemes need bilinear pairing operation,and resulting in low efficiency.An efficient aggregated signcryption scheme based on certificateless system without bilinear pairings is proposed in this thesis.This thesis proves that the aggregated signcryption scheme in two kinds of adversary unforgeability and confidentiality,and efficiency analysis,than final proof exists in more than one signcrypter scheme under the condition of not only has the confidentiality,unforgeability and without Bilinear pairings and having higher computing efficiency.(2)Most of the recipient signcryption scheme is a single message,and using bilinear pairings,so efficiency is not high,but this thesis uses lagrange interpolation and without bilinear pairing is composed of multi-receiver signcryption scheme.Ciphertext no longer lists the identity of the recipient,thus protecting privacy information,such as the identity of the addressee,therefore,it has the signcryption anonymity;Each receiver needs the same ciphertext information to satisfy the signciant fairness of the solution;Any third party can verify the identity of the cipher sender when it only owns the ciphertext to satisfy the public verifiability.Compared with the existing signcryption schemes,our scheme is more efficient,and it is not only confidentiality,unforgery,but also anonymity in the random oracle model.(3)The certificateless multi-receiver and multi-message signcryption scheme in this thesis has several advantages,which not only achieves the multi-receiver and multi-message mechanism,but also receives the unique ciphertext for each receiver,which makes the sender send the message more conveniently.Compared with the existing signcryption schemes,not only satisfies the confidentiality and forgery under the two rivals,but also verifiability and multi-message communication.