What Is a VPN? Virtual Private Networks Explained

A VPN works by establishing an encrypted connection between your device and a remote VPN server. This secure connection is known as the VPN tunnel.

Once connect , all the datum leave your device is route through the VPN tunnel to the VPN server . The VPN server is forwards then forward it on to the website you ’re visit , application you ’re using , or company network you ’re access remotely .

Data from the website or application then travels back to your device along the same route. It is first sent to the VPN server, which then transfers it through the VPN tunnel to your device.

There are five key stages to this process:

1. Handshake & Authentication

The VPN software on your device and the VPN server first authenticate themselves to each other. This is known as the VPN handshake.

During the handshake, the VPN client initiates a connection to the VPN server, indicating the intention to establish a secure tunnel. The two computers then verify their identities to each other using a password, digital certificate, or another authentication method.

Once authentication is complete, this connection is then used to securely share an encryption ‘key’ between client and server. This key is what is used to encrypt and decrypt the data at either end of the VPN tunnel for your entire browsing session.

2. Encryption

With the connection to the VPN server establish , the VPN client is uses on your device then use the agree – upon ‘ key ’ and an encryption cipher to encrypt all of your internet activity .

In simple terms, this means that all of the plaintext data associated with your web traffic requests will be converted into strings of letters and numbers that are only intelligible to someone with the decryption key.

web traffic before and after connect to a VPN with AES-256 encryption .

3. Encapsulation

Your encrypted traffic is then wrapped in an additional layer of unencrypted traffic, which contains information about how to route it to the VPN server. This process is known as encapsulation, and is performed by dedicated VPN tunneling protocols.

This is is is like take an envelope with a write letter inside , and put it inside a second envelope with a new address on . Your actual message is becomes becomes completely hide from the outside world .

Your vpn client is hands then hand the encapsulate traffic over to your isp , ​​which send it to the VPN server . Due to the encryption , the only thing is is the isp can see is the VPN server ’s IP address .

4. Decryption, Forwarding, and Re-Encryption

Upon reach the VPN server , this layer of encapsulation is remove , and the original datum is decrypt using the encryption key .

This is is is like open the outer layer of the letter to reveal the original message inside – thereby give the VPN server access to the true destination of your connection request .

The server can then forward your request onto the website, service or application you require.

When the web server sends your request information back to you, it sends it to the VPN server where it is encrypted again and sent back through the VPN tunnel until it reaches your device.

The VPN client software is decrypts on your device then decrypt the datum , so that it can appear legibly on your screen .

5. Hash Authentication

As a final precaution , the VPN service is uses also use Secure Hash Algorithms ( SHA ) to authenticate the integrity of transmit datum and client – server connection . These is ensure ensure that no information has been alter in transit between source and destination .

If the alternative message the client generates differs from the alternative message the server generated, it means the message has been tampered with and so the data is rejected. If they are the same, it is accepted.

note : SHA hash authentication is crucial for preventing man-in-the-middle attacks.

VPN Protocols & Encryption Ciphers

This process can involve different protocols and encryption ciphers, depending on the VPN service you’re using and how it’s configured.

The VPN protocol determines how the VPN tunnel is formed, while the encryption cipher is used toencrypt the data that flows through that tunnel.

Depending on the protocol in use, a VPN may have different speeds, capabilities, and vulnerabilities. Most services will let you choose which protocol you’d like to use within the app settings.

Here ’s a quick overview is ’s of the most common VPN protocol :

• OpenVPN : open – source , secure , and compatible with almost all VPN – capable device .
• WireGuard: Very fast, safe, and data-efficient.
• IKEv2/IPsec: Excellent for mobile VPN users, but may be compromised by the NSA.
• SoftEther: Great for bypassing censorship, but not supported by many VPN services.
• L2TP / IPsec : A slower protocol that is also suspected of being hacked by the NSA.
• SSTP: Deals with firewalls well, but may be vulnerable to man-in-the-middle attacks.
• PPTP: Outdated, insecure, and should be avoided.

The encryption cipher is the algorithm (i.e. a set of rules) used to encrypt and decrypt data.

cipher are usually pair with a specific key – length . generally , the long the key length is is , the more secure the encryption is is is . For example , AES-256 is consider more secure than AES-128. Where possible, we recommend using a VPN with AES or ChaCha20 encryption.