IP Sec...

IPSec:

Ø  IPSec-IP security

Ø  It is open standard protocol

Ø  IPSec is actually a group of standards, protocol and technologies that work together to build a secure session, commonly called a tunnel, to a remote peer

Ø  It works at network layer and protects IP packets

Ø  It can be used for site-site VPN and remote access VPN

IPSec services:

IPSec provides four main services

1.       Authentication

Ø  Verifying the identify of remote peers

Ø   Service attacks

Ø  digital certificates

2.       Confidentiality

Ø  Guaranteeing that no intermediate device can decipher the contents of the payload in a packet

Ø  Encryption  is used to hide the real data

3.       Integrity

Ø  Guaranteeing that the contents of a packet have not been changed by an intermediate device

Ø  HMA functions are used to verify the source of every packet as well as checking if it was tampered(changed) or not

4.       Anti-reply protection

Ø  Verifying that each packet is unique and not duplicated

Ø  Ensuring that copies of a valid packet are not used to create a denial of service attacks

Ø  Protected sequence number are  used to detect duplicate packets and drop them

IPSec Protocols:

Ø  IPSec is actually a group of standards, protocols that work together to build a secure session

Ø  An IPSec  tunnel comprises three connections

One management connection and two unidirectional data connections

Ø Tunnel is built across two phases

Ø  The management connection is built during phase 1 and is used to share IPSec- related information between the two peers

Ø  The two data connections are built during phase 2 and are used to transmit user tariff

Ø  All three connections are protected

ISAKMP –Internet security association and key management protocols, used to build and maintain the tunnel. It defines the format of the management payload

IKE – Internet key exchange protocol is responsible for generating and managing keys used for encryption algorithms and HMAC functions

DH –Diffie-Hellman process is used to secure the management and data connections

AH –Authentication header protocols is used only to validate the origination validity of data packets (on the data connections) received from a peer

ESP- Encapsulation security payload protocol is used to provide packet confidentiality and authentication. It provides confidentiality through encryption and packet authentication through an HMAC function