What is VPN?

Virtual Private Networks (VPNs) allow organizations to securely extend their LANs over the Internet by encrypting the data traffic. VPNs create the ideal infrastructure for providing a secure method for the exchange of data and network resources with employees, partners, suppliers and business associates.

The Internet: A Dangerous Place for Private Data

Internet-based remote access presents challenges in protecting the confidentiality and integrity of essential business information as it travels over the public Internet. Hackers using packet analysers can capture the data as it passes over the Internet and convert it into a readable format or gain entry into your network. Exposure to these security risks means unauthorized users can initiate fraudulent transactions, as well as steal, alter, or destroy confidential information, exposing your organization, customers, vendors, and business partners to financial losses.

To ensure data security on the Internet, there are three requirements:
Remote user identity authentication
Secure private transmission of data (no unauthorized listeners)
Verification of unadulterated data transmission

How VPN Works

A VPN is an umbrella term that refers to all the technologies enabling secure communications over the public Internet. VPN uses "tunnels" between two gateways to protect private data as it travels over the Internet. Tunneling is the process of encapsulating private IP packets into a public IPSec packet. Once the authentication and authorization between the VPN gateways is established, the tunnel is created and the users can send and receive data across the Internet.

A VPN tunnel establishes a secure connection between two sites over the Internet.

Types of VPN Connections

VPNs can be used to support the following types of connections:
Client to LAN. Used by mobile workers using dial-up Internet connections. A single VPN tunnel is used for each VPN client.
LAN-to-LAN. VPNs link two LANs together using a single tunnel that handles all the secure data traffic between two locations.
Intranets. VPNs allow remote offices and users to securely access internal TCP/IP applications running on the corporate Intranet.
Extranets. VPNs enable secure access to the corporate Extranet for vendors, partners, and customers.

IPSec VPNs

An international group organized under the Internet Engineering Task Force (IETF) developed the Internet Protocol Security (IPSec) protocol suite to provide security services at the network level. An IPSec tunnel through the Internet protects all data traffic passing through, regardless of the application.

IPSec technology is based on modern cryptographic technologies, making possible very strong data authentication and privacy guarantees. IPSec makes possible a secure VPN carved out of the insecure Internet to safely extend your private network through the public Internet. As a standard, IPSec is supported by a number of VPN vendors to allow interoperability.

VPN User Authentication

A VPN protects the integrity and confidentiality of information as it travels over the Internet using data encryption. However, a VPN lacks user authentication to verify the identity of the user at the other end of the connection. Establishing the identity of a VPN user prior to granting access to valuable, confidential resources protects the integrity of a VPN.

Digital certificates and public key infrastructure (PKI) are widely accepted as the best solution for establishing user identities with absolute confidence. A digital certificate is an electronic document used to identify an individual, a server, a company, or some other entity and to associate that identity with a public key. An essential element of cryptography is the use of secret codes, called keys, which are shared only by the communicating parties. Acting like a driver's license or a passport, a certificate provides a generally recognized proof of a person's identity. Public-key cryptography based on Public-Key Infrastructure (PKI) uses certificates to address the problem of impersonation.

VPNs and Internet Access Security

VPN is not a complete solution without symbiotic Internet access security for local networks. Using a VPN client program without access security at the remote location can open up a back door for hacker attacks on the corporate network. An effective VPN solution is built on a security platform that includes a firewall and support for other security services, such as network anti-virus.

GLOSSARY
Find out the definitions of VPN related terms.

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