What is TLS encryption?

Transport Layer Security or TLS is a cryptographic protocol that provides privacy and data integrity between two communicating applications. It was first introduced in 1999 as an upgrade of SSL Version 3.0. The TLS specification 1.2 was defined in 2008, and today it is considered to be the most widely deployed security protocol.

Features and technical details

TLS is used for applications, which deal with handling sensitive data or performing critical operations, such as web browsers, VPN connections, email services, VoIP, and instant messaging. All the information you send or receive online will be well encrypted so it cannot be intercepted and read by a third party.

The TLS protocol is composed of two layers: the TLS Record Protocol and the TLS Handshake Protocol. The TLS Record Protocol provides privacy and reliability of the connection, while the TLS Handshake Protocol encrypts your shared data and makes it unavailable to eavesdroppers, attackers, and other unauthorized parties.

A TLS stream of communication contains built-in controls to prevent tampering with any portion of the encrypted data. In addition, controls serves to prevent a captured stream of TLS data from being replayed at a later time. However, it should be mentioned here that the above guarantees apply only to data during transmission.

What are the key differences between TLS and SSL?

The major advantages of TLS that make it more secure and efficient protocol than SSL are:

  • HMAC message authentication
  • Psuedorandom function (PRF) to generate the key material
  • AES cipher suites, which are more secure algorithms
  • Simpler way of arriving at the CertificateVerify message

VPN Unlimited® uses the TLS 1.2 protocol for its browser extension.