What function does IPSec serve in a security protocol?

IPSec serves as a protocol suite designed to ensure secure communication over IP networks by providing a set of rules and mechanisms for encrypting and authenticating data packets. Its primary function is to establish a secure and private connection between devices over potentially untrusted networks, such as the Internet. This is achieved through various protocols, such as the Authentication Header (AH) and the Encapsulating Security Payload (ESP), which offer data confidentiality, integrity, and authentication.

The correct choice highlights IPSec’s role in setting the standards and operational procedures for secure information exchange. Through the implementation of these security measures, IPSec can protect against various threats, such as eavesdropping and tampering with data, ensuring that communications remain confidential and uninterrupted.

The other responses do not accurately reflect IPSec's purpose. Formatting data for applications pertains to application-layer tasks rather than network security. Governing routing over wide area networks relates more to protocols like BGP or OSPF, which focus on directing traffic rather than securing it. Connecting devices in a local area pertains to LAN technologies, which are distinct from the scope of IPSec's focus on secure communication across IP networks.