# What Is The Key Agreement Protocol And Why Is It So Important To Internet Commerce

Although Diffie and Hellman could not find such a system, they showed that public-key cryptography was actually possible by introducing the Diffie-Hellman key exchange protocol, a solution now widely used in secure communication to allow two parties to secretly agree on a common encryption key. [31] X.509 defines the most commonly used format for public key certificates. [45] The order of G should have an important prime factor to prevent the use of the Pohlig-Hellman algorithm to obtain a or b. For this reason, a Sophie Germain prime q is sometimes used to calculate p = 2q + 1, called a safe prime, since the order of G is then divisible only by 2 and q. Key tuning protocols require that certain types of credentials, such as symmetric keys, certificates, and public-private key pairs, be preconfigured on the nodes so that the key agreement procedure can be executed. .