Which layer 3 protocol allows for end-to-end encryption of FTP connections?

Which layer 3 protocol allows for end-to-end encryption of FTP connections?

• A. TLS
• B. SSH
• C. SSL
• D. IPsec

Answer: (D)

End-to-end encryption at the network layer is provided by IPsec. It operates in the IP layer, encrypting and authenticating IP packets as they travel from one host to another. Because IPsec protects the IP payload itself, any application that uses IP—such as FTP—gets encryption no matter what the application protocol is doing above the IP layer. This is different from TLS/SSL, which secure a specific connection at higher layers (for FTP you’d have FTPS, which encrypts the FTP session but sits on top of the transport/application layers), and from SSH, which secures sessions at a higher level (for file transfers you’d use SFTP, not FTP). So IPsec is the layer 3 mechanism that can provide end-to-end encryption for FTP traffic.

End-to-end encryption at the network layer is provided by IPsec. It operates in the IP layer, encrypting and authenticating IP packets as they travel from one host to another. Because IPsec protects the IP payload itself, any application that uses IP—such as FTP—gets encryption no matter what the application protocol is doing above the IP layer. This is different from TLS/SSL, which secure a specific connection at higher layers (for FTP you’d have FTPS, which encrypts the FTP session but sits on top of the transport/application layers), and from SSH, which secures sessions at a higher level (for file transfers you’d use SFTP, not FTP). So IPsec is the layer 3 mechanism that can provide end-to-end encryption for FTP traffic.