The original IP protocol does not contain any provisions for security. Security problems are compounded by the fact that IP packets do not go directly to a specific recipient, but are sent scattershot to all computers on a given network segment. Anyone can help themselves and read the packets. This leaves the door open to the misuse of data.
IP has been developed further for this reason. A secure version is now available: IPsec. VPN is based on IPsec.
IPsec stands for "IPsecurity Protocol" and was originally the name used by a working group of the IETF, the Internet Engineering Task Force. Over the years, this group has developed a framework for a secure IP protocol that today is generally referred to as IPsec.
It is important to note that IPsec itself is not a protocol, but merely the standard for a protocol framework. IPsec actually consists of a variety of protocols and algorithms for encryption, authentication and key management. These standards will be introduced in the following sections.