Research Of Content Extraction Signatures Based On RSA

Information is the most important resource in society, Information technology isthe wave of social development and core，information security becomes one ofimportant subjects in modern information society. Digital signature, which canprovide authentication, integrity and non-repudiation,is one of the key techniques ofinformation and plays a very important role in most areas.As the developing ofidentity-authentication and message-authentication need in network security,Traditional CES scheme can not meet the need in practice in multiparty interactionand resolves the problem of multiple signature and communication， thus urgent needto study more convenient and more efficient new system.Content Extraction Signatures (CES) is a new digital signature system.It enablesthe user to extract selectively verifiable content from signed content and isunnecessary for the user to contact with the original user. It improves the efficiency ofmultiparty interaction and resolves the problem of intensively computing and largeshare of storage demand, not convenient to practice during multiple signature andcommunication. In ensuring lawful extraction of messages,it effectively achieves themultiple delivery and verification of the message, so digital extraction signature hasbeen widely used in e-commerce and e-government.The thesis introduces the backgroud of digital signature emerge, the requirementneed to meet in practice and the principle of digital signature and procedure, Itdiscusses all kinds of digital signature scheme based on the RSA and DSA in detail，thoroughly analysis signature scheme based on RSA, and propose an improvedscheme.Traditional RSA-based scheme of CES effectively solves the problem of multiplesignature and verification,however these schemes need to calculate and signatureeach paragraph or document, It will result in a costly computation and large of storage,In view of this, this paper presents an improved extraction signature based on RSA, inthe case of continuous N-paragraph or document number need to extract(this situationexists widely in practical applications),if only calculated once a signature, this canreduce N-1signature, Verifier correspondingly reduces the amount of verified computing of the extracted documents, Effective improvement of the traditionalextraction signature and prove the correctness of the new scheme, analysis of theperformance of the new program thoroughly.Under the premise of the guarantee of scheme correctness, the results show thatthe improved scheme reduces the numbers of signature and verification times, theamount of computational and the share of storage, It improves the efficiency andperformance of the content extraction signature scheme based on RSA.