What are SSL and TLS? Why are certificates needed?

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols that provide a secure connection between a client and a server on the internet. TLS is a more modern and secure version of SSL.

Main tasks of SSL/TLS:

• Encrypting data to protect against interception and eavesdropping.
• Authenticating the server (and sometimes the client) to confirm authenticity.
• Ensuring data integrity to prevent modification during transmission.

Certificates are used to verify the authenticity of the server (or client). A certificate contains the public key and information about the owner, signed by a trusted certification authority (CA). When a client connects to a server, it checks the certificate to ensure that the connection is established with the genuine server and not an attacker (man-in-the-middle attack).

Example: HTTPS uses TLS for secure data exchange between the browser and the website, and the certificate confirms that the website truly belongs to the declared owner.