Digital signature 曹天杰 Tianjie Cao ticao@cumt.edu.cn College of Computer Science and Technology, China University of Mining and Technology, Xuzhou China 中国矿业大学计算机科学与技术学院 2003.6.6
1 Digital Signature 曹天杰 Tianjie Cao tjcao@cumt.edu.cn College of Computer Science and Technology, China University of Mining and Technology, Xuzhou, China 中国矿业大学计算机科学与技术学院 2003.6.6
Definitions Definitions Digital Signature-a data string which associates a message with some originating entity Digital Signature Generation Algorithm -a method for producing a digital signature Digital signature verification algorithm-a method for verifying that a digital signature is authentic (i. e, was indeed created by the specified entity Digital Signature Scheme-consists of a signature generation algorithm and an associated verification algorithm
2 Definitions • Definitions – Digital Signature - a data string which associates a message with some originating entity – Digital Signature Generation Algorithm – a method for producing a digital signature – Digital signature verification algorithm - a method for verifying that a digital signature is authentic (i.e., was indeed created by the specified entity). – Digital Signature Scheme - consists of a signature generation algorithm and an associated verification algorithm
Applications Digital Signatures can provide authentication Data Integrity Non-Repudiation One application Certification of public keys in large networks
3 Applications Digital Signatures can provide • Authentication • Data Integrity • Non-Repudiation One Application • Certification of public keys in large networks
Classification Digital signature schemes with appendix require the original message as input to the verification algorithm Digital signature schemes with message recovery do not require the original message as input to the verification algorithm. In this case, the original message is recovered from the signature itself
4 Classification • Digital signature schemes with appendix require the original message as input to the verification algorithm. • Digital signature schemes with message recovery do not require the original message as input to the verification algorithm. In this case, the original message is recovered from the signature itself
Classification(cont) Taxonomy of digital signatures randomized message recovery deterministic signature schemes randomized appendix deterministic
5 Classification (cont) • Taxonomy of digital signatures signature schemes message recovery appendix deterministic randomized randomized deterministic