15.12.8 What Is a Virtual Private Network (VPN), and Why Is It Used?
- Why Is a VPN Needed?
- Why Is It Called a "Virtual" Private Network?
- How Does a VPN Work?
- Does a VPN Create a New Internet Connection?
- Where Are VPNs Commonly Used?
- Are VPNs Used on Public Wi-Fi?
- Does a VPN Make Internet Use Anonymous?
- Does a VPN Slow Down the Internet?
- Is HTTPS the Same as a VPN?
- Who Uses VPNs?
- Will VPNs Continue to Be Important?
- What Should You Remember?
Short Answer
A Virtual Private Network (VPN) allows information to travel securely across the public Internet as though it were being transmitted through a private communication network. It does this by encrypting the data before transmission so that only the intended recipient can read it. VPNs are widely used by businesses, governments, and individuals to protect sensitive information, enable secure remote working, and improve privacy when using public networks.
Why Is a VPN Needed?
The Internet is a public communication network.
Whenever information is transmitted across the Internet, it may pass through many different routers and communication providers before reaching its destination.
Although these organizations forward the information correctly, users often wish to protect the confidentiality of the data being transmitted.
Examples include:
- financial transactions;
- business documents;
- medical records;
- government information;
- personal communications; and
- confidential research.
A VPN provides an effective way of protecting this information while it travels across public communication infrastructure.
Why Is It Called a "Virtual" Private Network?
Traditionally, organizations requiring secure communication between offices installed dedicated private communication links.
These leased lines provided excellent security because no other organization used the same physical infrastructure. However, dedicated communication links are expensive and may be impractical when offices are widely separated. A VPN achieves a similar result without requiring dedicated cables. Instead, it creates a virtual private communication path across the shared public Internet.
Although the physical communication network is shared with millions of other users, the encrypted information remains private.
How Does a VPN Work?
The basic principle is straightforward.
Before information leaves the sender's computer, it is encrypted. The encrypted information then travels across the Internet in the same way as any other data. When it reaches the destination, it is decrypted and restored to its original form. Anyone intercepting the communication while it is travelling across the Internet would see only encrypted data that appears meaningless without the correct encryption keys.
The VPN therefore provides confidentiality even though the communication takes place over public infrastructure.
Does a VPN Create a New Internet Connection?
No.
A VPN does not replace the Internet. Instead, it operates over the existing Internet connection.
The Internet continues to provide the physical communication path, while the VPN adds a secure communication layer between the two endpoints. For this reason, a VPN is often described as an overlay network.
It creates a logical communication path without requiring any changes to the underlying Internet infrastructure.
Where Are VPNs Commonly Used?
VPNs are used in many different situations.
Businesses commonly use VPNs to allow employees working from home to access company networks securely. Organizations also use VPNs to connect branch offices located in different cities or countries. Individuals often use VPNs when:
- connecting through public Wi-Fi;
- travelling overseas;
- accessing work systems remotely;
- protecting personal privacy; or
- securing Internet communications.
In each case, the objective is the same—to protect information while it is transmitted across the public Internet.
Are VPNs Used on Public Wi-Fi?
Yes.
Public Wi-Fi networks, such as those found in airports, hotels, cafés, and libraries, are convenient but may present additional security risks. Although many websites now use encrypted connections, a VPN provides another layer of protection by encrypting all Internet traffic leaving the user's device.
For this reason, many organizations require employees to use a VPN whenever connecting through public wireless networks.
Does a VPN Make Internet Use Anonymous?
Not completely.
A VPN improves privacy by hiding your Internet traffic from the local network and by replacing your public IP address with that of the VPN service. However, it does not make a user completely anonymous. Internet service providers, VPN operators, websites, and online services may still collect information depending on the circumstances. True anonymity depends upon many factors beyond simply using a VPN.
A VPN should therefore be viewed primarily as a security and privacy tool rather than as a guarantee of anonymity.
Does a VPN Slow Down the Internet?
Sometimes.
Because information must be encrypted before transmission and decrypted after reception, a small amount of additional processing is required. In addition, traffic may be routed through a VPN server located some distance away. These factors can introduce slightly higher communication delays.
Modern computers and high-speed Internet connections usually make these effects relatively small, and for many users the additional security is well worth the modest reduction in performance.
Is HTTPS the Same as a VPN?
No.
Although both improve security, they protect different parts of the communication process.
HTTPS encrypts communication between a web browser and a particular website. A VPN encrypts all Internet traffic between the user's device and the VPN server, regardless of which applications are being used. For example, a VPN can protect:
- web browsing;
- email;
- file transfers;
- video conferencing; and
- many other Internet applications.
The two technologies often work together rather than replacing one another.
Who Uses VPNs?
VPNs are now used by a wide variety of organizations, including:
- businesses;
- government agencies;
- universities;
- healthcare providers;
- financial institutions; and
- private individuals.
The widespread adoption of remote working has made VPN technology an essential part of many modern communication systems.
Millions of employees now access corporate networks securely from home using VPN connections.
Will VPNs Continue to Be Important?
Almost certainly.
As organizations increasingly rely upon cloud computing, distributed workplaces, and mobile communication, secure Internet connectivity becomes even more important. At the same time, cyber threats continue to evolve. VPN technology therefore remains an important component of modern network security, although it is increasingly used alongside other security measures such as:
- multi-factor authentication;
- digital certificates;
- firewalls;
- endpoint security software; and
- encrypted web services.
Together, these technologies help protect information as it moves across the global Internet.
What Should You Remember?
A Virtual Private Network allows secure communication across the public Internet by encrypting information before it is transmitted.
Although it uses the existing Internet infrastructure, the VPN creates a private logical communication path between the communicating devices.
VPNs are widely used to support remote working, connect geographically separated offices, protect communications over public Wi-Fi, and safeguard sensitive information. They illustrate how the Internet can provide both worldwide connectivity and secure private communication using the same underlying communication infrastructure.
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