Key exchange is a method used in cryptography to securely share encryption keys between parties. This process ensures that both parties can communicate privately without anyone else being able to intercept or understand the messages. Common algorithms for key exchange include the Diffie-Hellman method and the RSA algorithm. During a key exchange, each party generates a pair of keys: a public key, which can be shared openly, and a private key, which is kept secret. By using these keys, the parties can create a shared secret that allows them to encrypt and decrypt messages, ensuring secure communication over potentially insecure channels.