HP-UX IPSec Overview

Internet Key Exchange (IKE)

•Digital Signatures

IKE Preshared Key Authentication

With preshared key authentication, you must manually configure the same, shared symmetric key on both systems, a preshared key. The preshared key is used only for the primary authentication. The two negotiating entities then generate dynamic shared keys for the IKE SAs and IPSec/QM SAs.

Preshared keys do not require a Certificate Authority or Public Key Infrastructure.

Digital Signatures

Digital signatures are based on security certificates, and are managed using a Public Key Infrastructure (PKI). HP-UX IPSec supports the following security certificates from the following products:

•VeriSign Managed PKI (formerly VeriSign OnSite for VPNs)

•Baltimore UniCERT 3.5

For more information on using certificate-based authentication for IKE, see Chapter 4, “Using Certificates with HP-UX IPSec,” on page 113.

Re-using Negotiations

For efficiency, you can specify that a single ISAKMP Phase One (ISAKMP/MM) SA can be used to negotiate multiple ISAKMP Phase Two (IPSec/QM) negotiations.

Conversely, you can specify that each Phase One SA can be used for only one ISAKMP Phase Two negotiation. The IKE daemon will create a new ISAKMP SA for each IPSec SA negotiation. This can provide a feature known as Perfect Forward Secrecy (PFS) with key and identity protection. With PFS, the compromise (exposure) of one key exposes only the data protected by that key.

IKE Automatic Re-keying

The IKE protocol also allows HP-UX IPSec to dynamically negotiate new IPSec keys rather than exposing the same key for long periods. You can configure key lifetimes based on time or number of bytes sent.

Chapter 1

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