Calculation method:
An algorithm for generating the hash value of certain data fragments, such as messages or conversation items. Using a good hashing algorithm, the changes made to the input data can change all the bits in the resulting hash value; Therefore, hashing is very useful for detecting modifications in data objects such as messages. In addition, it is impossible for a good hash algorithm to construct two independent inputs with the same hash through calculation. Typical hash algorithms include MD2, MD4, MD5 and SHA- 1. Hash algorithm is also called "hash function".
See also: Hash-based Message Authentication Mode (HMAC), MD2, MD4, MD5, Message Digest, Secure Hash Algorithm (SHA- 1).
MD5 is a one-way 128-bit hashing scheme conforming to industrial standards, which was developed by RSA Data Security, Inc. Various "Point-to-Point Protocol (PPP)" vendors use it for encryption authentication. Hash scheme is a method of transforming data (such as password), and the result is unique and cannot be restored to the original format. Challenge handshake authentication protocol (CHAP) uses challenge response and one-way MD5 hash as response. In this way, you can prove to the server that you know the password without sending it over the network.
Challenge handshake authentication protocol (CHAP)RFC 1994 describes the challenge response authentication protocol related to point-to-point protocol (PPP). This protocol uses the industry standard MD5 hashing algorithm to hash the combination of the challenge string (issued by the authentication server) and the user password in the response.
point-to-point protocol
An industry standard protocol suite that uses point-to-point links to transmit multiprotocol datagrams. There are documents about PPP in RFC 166 1.
See also Compression Control Protocol (CCP), Remote Access, Request for Comment Document (RFC), Transmission Control Protocol/Internet Protocol (TCP/IP), Autonomous Tunnel.