The Research Of Signcryption Based On Self-certified Public Key

With the rapid development of computer networks, the insecure network node hasbrought great threat to the user’s privacy and the integrity of data. Signcryption is able toachieve the encryption and signature for the date in an efficient way, and protect theconfidentiality and unforgeability of users’ data. Existing signcryption schemes, or lowefficient, or existing significant security vulnerabilities. The research of the safe and efficientdigital Signcryption schemes and digital Signcryption schemes with spacial properties hasbecome a hot research focus.By reading a lot of literature, security analysis of the existing certificateless signcryptionschemes, it has be found that the part of the schemes are insecure against the public keyreplacement attack, and do not meet public key authentication and forward security. In thatcase, with an improved proposal of Debiao He, proposed a new general signcryption schememodels and security models. The new model is based on the existing model, by adjusting theuser’s private key to generate the sequence, to solve the problem that the public keyreplacement. The new model has self-certifid property. An improved certificatelesssigncryption scheme is proposed which based on the new model and the existingcertificateless signcryption schemes. Analysis shows that the improved scheme has publicverifiability and forward security, which greatly expands the scope of application of theprogram. The confidential of improved scheme is reduced to the advantage of resolving DDHproblem and the existential unforgeable of improved scheme is reduced to the advantage ofresolving DL problem in the random oracle model. Compared with the existing signcryption,improved scheme is efficiency without pairing.In the smart home system, the user is sent by the intelligent terminal control commands to,the control commands which user sends to household appliances by the intelligent terminalneed to encrypt and authenticate. Signcryption can meet this demands, ensure the authenticityof the user and home appliances and protection of user privacy is not compromised. Thecommunication control protocol in the intelligent terminal operation should be efficientbecause of the limited computing power and battery life of intelligent terminal. Online/offlinesigncryption scheme can further reduce the amount of calculation of signcrypted stage.Therefore, online/offline program is ideal for smart home control protocol. This paperpresents a secure and efficient online/offline signcryption scheme based on the self-certifiedpublic key cryptosystem. The accuracy, confidentiality and unforgeable of the new scheme areanalyzed in detail. Using the random oracle model, it is proved that the confidentiality of thenew scheme is equivalent to the advantage of resolving DDH problem and the unforgeable of the new scheme is equivalent to the advantage of resolving DL problem. he adaptive chosenmessage attack under the identity and proved difficult issues of confidentiality and DDH newscheme is equivalent, can not be forged with the discrete logarithm problem is equivalent. Thenew scheme is without pairing, and only one scalar multiplication without other complexoperations in the online signcrytion stage. At the same time, the new scheme can be verifiedin public, so that the unsigncryption can be devided into two parts: verified and decrypted,with an independent validation of equipment (such as gateways) to verify, and the householdequipment only need to decrypt, further improving the performance of the system. The newscheme is based on self-certified, user’s private key is confidential to a trusted third party, anddoes not need to explicitly verify the public key, which greatly enhances the efficiency of thescheme and protect the confidentiality and integrity of user data further more.In the electronic bidding system, the tender of bidders need to be signcrypted and send tothe bid committee. In order to improve the fairness, it is required a certain amount ofcommittee to cooperation to view the bids. Threshold unsigncryption scheme is proposed forthe electronic bidding system. Combined with the advantages of self-certified public keyscheme and threshold signcryption system, proposed a new threshold based on self-certifiedsolution signcryption scheme. Using the random oracle model, new scheme is proved to beconfidential and existentially unforgeable against the adaptive choosing message and IDattack and internal collusion attack. And the new scheme has the same efficiency with theexisting scheme which is certificate-based.