How do digital certificates work in HTTPS?

Digital certificates in HTTPS provide a secure way to authenticate the identity of a website and encrypt its data.

Digital certificates, also known as SSL/TLS certificates, play a crucial role in the HTTPS (Hypertext Transfer Protocol Secure) protocol, which is used to secure communication over a computer network. They are essentially small data files that digitally bind a cryptographic key to an organisation's details. When installed on a web server, they activate the padlock and the HTTPS protocol, allowing secure connections from a web server to a browser.

The process begins when a browser or server attempts to connect to a website secured with SSL. The browser requests that the web server identifies itself. The web server sends the browser a copy of its SSL certificate. The browser checks whether it trusts the SSL certificate. If so, it sends a message to the web server. The web server then sends back a digitally signed acknowledgement to start an SSL encrypted session. This encrypted data is then shared between the browser and the web server, ensuring that the data remains private and integral.

Digital certificates are issued by Certificate Authorities (CAs). These are trusted entities that verify the identity of websites and issue SSL certificates to them. When a browser receives a certificate, it checks that it's signed by a trusted CA and that the certificate is still valid. If either of these checks fails, the browser will display a warning to the user, indicating that the website may not be secure.

In essence, digital certificates serve two main purposes. Firstly, they verify the identity of a website, ensuring that you're not connecting to a malicious impostor site. Secondly, they facilitate the encryption of data sent between the browser and the web server, which prevents eavesdroppers from reading or modifying that data. This is particularly important when sensitive information, such as credit card numbers or personal details, is being transmitted.

In conclusion, digital certificates are a fundamental part of web security. They provide a way to authenticate websites and encrypt data, ensuring that internet users can browse and shop with confidence.