Authentication can be employed at both the physical level and the virtual level. At the physical level, identification can be made through user passwords, magnetic or smart cards, biometric devices, and single sign-on systems. The nature of the workplace has drastically changed and will continue to change in the coming years. VPNs have recently gained popularity because of their authentication and encryption capabilities. Using public networks, such as the Internet, VPNs also provide companies with significant cost savings.
Savings also come in terms of the equipment and personnel needed for remote access.
With business demanding changes in the use of technology, VPNs provide a means of obtaining a cheap and secure way of gaining remote access to a company's network. This configuration could provide real benefits for the accounting profession, as industry trends continue to move toward virtual offices and client-based accounting professionals. In the transport mode, only the payload of the IP packet is protected. Several tunneling protocols exist. Today, PPTP is by far the most popular tunneling protocol.