What does "key exchange" refer to in cryptography?

Key exchange in cryptography refers to the process of sharing cryptographic keys between users, enabling secure communication over potentially insecure channels. This process is essential in establishing a shared secret that can be used for encrypting messages, ensuring both parties can communicate securely without an eavesdropper intercepting the key.

The significance of key exchange lies in the fact that secure communication protocols, such as SSL/TLS or secure messaging apps, rely on the ability to safely transmit keys to establish encrypted channels. Various key exchange techniques exist, such as Diffie-Hellman, RSA, and elliptic curve methods, with each designed to facilitate this secure transfer in different contexts.

In contrast, other options deal with different aspects of cryptography: the method of encrypting data is a broader topic that encompasses various encryption techniques; a type of encryption algorithm identifies specific procedures used to encode data, and the storage of cryptographic keys pertains to the methods for securely keeping keys for future use rather than their exchange. Thus, the process for sharing cryptographic keys is the core focus of key exchange, making it the correct definition in this context.