What characteristic defines link encryption?

Link encryption is characterized by its practice of encrypting the entire data packet, which includes both the headers and trailers. This approach ensures that all aspects of the communication are protected, making it difficult for unauthorized entities to access any part of the transmission. By encrypting the entire packet, the integrity and confidentiality of the data are maintained across the entire communication link from the source to the destination.

In contrast, methods that only encrypt specific parts of the data, such as just the payload or omitting headers entirely, do not provide the same level of security, as key information could still be exposed in the headers. Additionally, while there are encryption methods that secure data at the application layer, link encryption operates at a lower level, generally on the data link layer of the OSI model, rather than being confined to the application layer.

Thus, the comprehensive nature of link encryption, by encompassing all components of a packet, is what distinctly defines this characteristic within cybersecurity practices.