Key Exchange: The process of transferring cryptographic keys between parties over a network, enabling secure communication. Key exchange is typically used in protocols like Diffie-Hellman and RSA to securely share keys that will later be used to encrypt and decrypt messages. The transfer is done in such a way that even if the communication is intercepted, the intruder cannot derive the original key. This process is a fundamental part of many secure network protocols, including SSL/TLS, which provides secure web browsing.