Suite of IPsec protocols at the service of the VPNs and mobility

To facilitate inter- and intra-company communications, and thus improve business relations and productivity, many companies are looking for efficient, secure communication tools. Companies generally subscribe to VPN (Virtual Private Network) services from specialized companies (Internet service providers, operators, etc.).

In the future, these companies would like to offer their employees even greater flexibility, enabling them to communicate with any type of equipment (controlled, of course), anywhere and even on the move. Today, the techniques associated with mobility and security do not offer such flexibility, but the scientific community is working on it.

Whenever a company's communications are routed over a public network, it's important to be extremely cautious. Indeed, what is the proof that these exchanges will not be subject to eavesdropping during transfer, and that their content will not be revealed to a third party? This is just one of the many forms that industrial espionage can take.

What's more, what's to ensure that the traffic received actually comes from the declared terminal, and not from a malicious terminal that has usurped the identity of a legitimate terminal? This last question is all the more problematic as, in the long term, it is highly likely that users will be able to connect to their corporate network from any type of terminal.

The IPsec (IP security) protocol, the secure version of IP, is the most comprehensive solution for this security issue, covering the widest range of scenarios.

This protocol, standardized by the IETF, makes it possible to authenticate communicating entities, ensure the authenticity, integrity and confidentiality of exchanged data, and maintain an acceptable level of security throughout connections, by periodically updating security parameters. IPsec is widely used today, in a VPN context, to secure the interconnection of remote private networks and, to a lesser extent, to secure remote access by a nomad to his or her private corporate network. On this latter point, IPsec is competing with SSL (Secure Socket Layer) VPN.

If this trend continues, operators' network infrastructures should gradually evolve towards "all-IP", and the IPsec solution should see new uses.

This file describes the IPsec protocol suite, in particular the three sub-protocols: AH (Authentication Header), ESP (Encapsulating Security Payload), and...