COMP 4670 Lecture Notes - Message Authentication Code, Message Authentication, Cryptographic Hash Function

• School: University of Windsor
• Department: Computer Science
• Course: COMP 4670
• Professor: Erfani

Document Summary

It was mentioned earlier in this chapter that integrity and protection security services are needed to protect against active attacks, such as falsification of data and transaction. Protection against such attacks is known as message authentication. Message authentication a message, file, document, or other collection of data is said to be authentic when it is genuine and came from its alleged source. Message authentication is a procedure that allows communicating parties to verify that received messages are authentic. The two important aspects are to verify that the contents of the message have not been altered and that the source is authentic. Sometimes, we need to verify a message"s timelines (i. e. , it has not been purposely delayed and replayed) and sequence relative to other messages following between two parties. Authentication with conventional encryption sender and receiver share a key, then only the genuine sender would be able to encrypt a message.