How many of you use VPN? VPN stands for Virtual Private Network and if you work for a large company or do business with a large company then chances are you log in to your network via a Virtual Private Network. A VPN is a network within a larger network such as the Internet or a company LAN. But the VPN is not characterized by the physical wires. Instead the VPN uses open connections or virtual circuits through the larger network.

VPNs can enable secure communications over the public network by using authentication or encryption. One of the ways to secure communications of the VPN is by using a shared secret key such as is generated by the Diffie-Hellman cryptographic algorithm.

The Diffie-Hellman key exchange allows two computer users to jointly establish a shared secret key without ever having to know of one another. Later, this key can be used for encrypting subsequent communications across an insecure channel using a symmetric key cipher.  Keep in mind that the Diffie-Hellman algorithm does not encrypt data nor does is it used to make digital signatures. The algorithm is used only for generating a shared secret.

Continue reading I’ve Got a Secret – Key, That Is