Internet Protocol Security (IPsec) is a collection of key security standards. As such, IPsec offers several protection mechanisms and several modes of operation.
Analyze the IPsec two protection mechanisms of Encapsulating Security Payload (ESP) and Authentication Header (AH) in terms of protection, authentication, and confidentiality.
Differentiate the ESP two operation modes of Transport and Tunnel modes and explain which mode provides more protection and why.
Respond in 200-250 words
IPsec offers two main mechanisms to secure data packets:
Authentication Header (AH): Provides data integrity and origin authentication. It adds a header to the IP packet containing a digital signature calculated over the original data and a sequence number. This ensures data hasn’t been tampered with during transmission and verifies the sender’s identity. However, AH doesn’t encrypt the data itself.
Encapsulating Security Payload (ESP): Offers confidentiality, authentication, and integrity. ESP encrypts the entire data payload of the packet along with a new header containing authentication information similar to AH. This ensures confidentiality as only authorized parties can decrypt the data, while also providing authentication and integrity like AH.
In essence:
ESP’s Operation Modes: Transport vs. Tunnel
ESP comes in two modes:
Tunnel mode provides more protection:
However, tunnel mode introduces additional processing overhead due to the extra encryption and decryption of the entire packet.