Network Layer Security

Cryptographic methods and protocols have been designed for different purposes in securing communication on the Internet. These include the SSL and TLS for HTTP Web traffic, S/MIME and PGP for e‐mail, and Internet Protocol security (IPsec) for network layer security. This chapter mainly addresses security only at the IP layer and describes various security services for traffic offered by IPsec. The current key management options required for both authentication header (AH) and Encapsulating Security Payload (ESP) are manual keying and automated keying via Internet Key Exchange (IKE). The chapter provides an overview of Oakley and then looks at Internet Security Association and Key Management Protocol (ISAKMP). The ISAKMP Payloads can be used in exchanges defined for a specific Domain of Interpretation (DOI). The chapter describes the processing for each of the payloads.