Configuring Ike; Overview; Ike Security Mechanism; Ike Operation - HP 5120 SI Series Security Configuration Manual

Configuring IKE

This feature is applicable only to the switches in FIPS mode. For more information about FIPS mode, see
"Configuring

Overview

Built on a framework defined by the Internet Security Association and Key Management Protocol
(ISAKMP), Internet Key Exchange (IKE) provides automatic key negotiation and SA establishment services
for IPsec, simplifying the application, management, configuration and maintenance of IPsec
dramatically.
Instead of transmitting keys directly across a network, IKE peers transmit keying materials between them,
and calculate shared keys respectively. Even if a third party captures all exchanged data for calculating
the keys, it cannot calculate the keys.

IKE security mechanism

IKE has a series of self-protection mechanisms and supports secure identity authentication, key
distribution, and IPsec SA establishment on insecure networks.
Data authentication
Data authentication involves two concepts:
Identity authentication—Mutual identity authentication between peers. Two authentication methods
•
are available: pre-shared key authentication and PKI-based digital signature authentication (RSA
signature).
• Identity protection—Encrypts the identity information with the generated keys before sending the
information.
DH
The Diffie-Hellman (DH) algorithm is a public key algorithm. With this algorithm, two peers can
exchange keying material and then use the material to calculate the shared keys. Due to the decryption
complexity, a third party cannot decrypt the keys even after intercepting all keying materials.
PFS
The Perfect Forward Secrecy (PFS) feature is a security feature based on the DH algorithm. By making
sure keys have no derivative relations, it guarantees a broken key brings no threats to other keys. For IPsec,
PFS is implemented by adding an additional key exchange at IKE negotiation phase 2.

IKE operation

IKE negotiates keys and establishes SAs for IPsec in two phases:
1. Phase 1—The two peers establish an ISAKMP SA, a secure, authenticated channel for
communication.
2. Phase 2—Using the ISAKMP SA established in phase 1, the two peers negotiate to establish IPsec
SAs.
FIPS."
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