out cryptographic authentication of the remote user.VPN cryptographic authentication is used to securely validate the identity of a remote user and determine the level of access and security appropriate for them. It may also be used to authenticate for the exchange of secret or public payload encryption keys. Shared secret or Private encryption keys rely on both parties knowing the keys value. Challenge response can be used to ensure that the hashes of the Private key and not the key itself are transmitted. In addition, one-time password variations can be employed to ensure that the Private key is changed every time that they are used.Before data is encapsulated and sent over the Internet, it is encrypted. This is called data payload encryption. Data payload encryption is used to encode all the contents of an IP packet, both data and header, to hide any information about the nature of the network and data being transmitted. This will prevent any snoopers from gathering information about the network that is sending the packet. Data payload encryption can be accomplished in any one of a number of secure cryptographic methods and will be different depending on the VPN solution that is implemented.In a VPN all traffic between networks should be transparent to the computers. To do this you need to set up a private and protected tunnel through the Internet. Computers outside of the VPN should not be able to view or insert data in the communication stream. IP packets contain all kinds of information like program files, spreadsheet data, network traps, and even other IP packets. This is also called IP on IP. By encapsulating encrypted IP packets the information about the networks and the data being exchanging is reduced to the sending and receiving routers. Just like data payload encryption, encapsulation can be done in many ways depending on your solution. One of the advantages to VPNs is that you can use arbitrary IP addresses....
