What are TLS and mTLS? What is the difference between them?

TLS (Transport Layer Security) is a protocol that provides encryption and data protection during transmission over a network. It guarantees confidentiality, integrity, and server authentication, preventing data interception and forgery.

mTLS (mutual TLS) is an extension of TLS where authentication occurs not only for the server but also for the client. Both parties exchange certificates and verify each other, which enhances security and is used in scenarios where verifying the authenticity of both sides is important.

Main difference:

• TLS: the client verifies the server, but the server does not verify the client (usually).
• mTLS: both the client and the server verify each other using certificates.

An example of mTLS application is interaction between microservices within a secured infrastructure, where it is necessary to ensure that requests come from trusted services.