VPNs secure transmitted data with the help of encryption and protocols. Encryption is the process of converting plain data into cryptic data so that only authorized computers with the right decoder key will be able to read and use it. For instance, all of the emails and chat messages we send and receive are protected by end to end encryption.
In VPNs, computers at the sending or receiving end of the secure tunnel share encrypted data. Anyone outside the tunnel won’t be able to decrypt what is being transferred through the VPN tunnel. Now there are two basic types of VPN encryption. Symmetric key encryption and public-key encryption. Here’s how both of these encryption types work:
- Symmetric-key encryption – All users or computers share the same key for both encryption and decryption.
- Public key encryption – Each user or a computer has its own set of public and private keys. While one computer or a user encrypts certain data with its private key, the other computer or a user decrypts that data using the corresponding public key.
But encryption is not solely responsible for securing transmitted data. VPNs also use protocols like IPSec, L2TP, PPTP, SSL, and OpenVPN among others to securely transmit data. For instance, a site-to-site VPN uses IPSec to securely transmit data over IP networks. Whereas a remote-access VPN can use a variation of Point-to-point Protocols like L2F, PPTP or even L2TP.