What is the primary use of hash (one-way) encryption in networking?

The primary use of hash (one-way) encryption in networking is signing files, which serves to ensure data integrity. Hashing functions create a fixed-size output (hash) from input data of any size, such that even a small change in the input will dramatically alter the hash output. This property allows for the verification of data integrity; if the hash of the file matches the original hash value at the time of signing, it confirms that the file has not been altered or corrupted during transmission.

When a file is signed with a hash, it not only proves that the file is intact but also authenticates the source of the file. The signing process often involves using a private key to generate a digital signature based on the hash value, allowing the recipient to verify the signature with the corresponding public key.

While the other options mention important aspects of security, they relate to different principles. Encrypting files for confidentiality focuses on protecting the content from unauthorized access, key exchange pertains to securely sharing cryptographic keys for setting up secure communications, and user authentication for non-repudiation involves ensuring that a user cannot deny their actions. However, these do not specifically pertain to the primary function of hashing, which revolves around ensuring data integrity through verification rather than privacy or