With the development of INTERNET, people have gradually become inseparable from the Internet. Whether it is e-commerce or communication between individuals, they have put forward requirements for communication security. The original design of TCP/IP did not take security into consideration, so the IETF Internet Engineering Task Force developed the Internet Protocol SECurity IPSEC protocol suite to achieve communication security. In the next generation of INTERNET IPv6, IPSEC will be part of IP. The basis of IPSEC is the application of modern cryptography in computers. It relies on encryption algorithms to achieve confidentiality, message verification code, MAC Message Authentication Code to achieve data integrity, and Integrity digital signatures to achieve authentication. Authentication IPSEC can be divided into two One part implements the AH protocol and ESP protocol operations for encrypting and decrypting input and output data in the TCP/IP protocol stack, and the other part prepares AH and ESP for normal operation to establish the SA Security Association necessary for communication. This is IKE The goals that the Internet Key Exchange protocol needs to achieve.
