Which protocol for IPsec uses the Diffie-Hellman algorithm to derive a master key and a unique session key?

Which protocol for IPsec uses the Diffie-Hellman algorithm to derive a master key and a unique session key?

• A. ISAKMP
• B. Oakley
• C. DOI
• D. IKE

Answer: (B)

The key idea here is that Diffie-Hellman-based key agreement is used to produce a shared secret (a master key) from which unique keys for each session are derived. The Oakley protocol provides the specific DH-based method for IPsec’s key exchange, defining how peers compute that shared secret and then derive the per-session encryption and integrity keys used to secure the traffic. ISAKMP serves as the framework for negotiating and managing these exchanges, while IKE oversees the overall process, often incorporating Oakley for the actual key agreement. DOI isn’t a related IPsec protocol. So the protocol that directly uses Diffie-Hellman to derive the master key and per-session keys is Oakley.

The key idea here is that Diffie-Hellman-based key agreement is used to produce a shared secret (a master key) from which unique keys for each session are derived. The Oakley protocol provides the specific DH-based method for IPsec’s key exchange, defining how peers compute that shared secret and then derive the per-session encryption and integrity keys used to secure the traffic. ISAKMP serves as the framework for negotiating and managing these exchanges, while IKE oversees the overall process, often incorporating Oakley for the actual key agreement. DOI isn’t a related IPsec protocol. So the protocol that directly uses Diffie-Hellman to derive the master key and per-session keys is Oakley.