Google’s official documentation and Certificate Authorities, define an SSL Certificate as a security measure that protects your website from man-in-the-middle attacks. It ensures that your customers’ connection, their data, your website and your company are all secure. Let’s find out how an SSL Certificate protects you from the cyber attacks known as “man-in-the middle attacks”.
What is a Man-in-the-Middle attack?
A Man-in-the-Middle attack occurs when an attacker places himself between the website server and the client’s browser, impersonating one of them. In other words, when the server is connecting to the visitor’s browser, he is actually dealing with the hacker and vice versa. Thus, although the browser “thinks” that it established an encrypted connection with the server, both of them are actually “talking” to the attacker who can view and modify the data. For this reason, everyone calls it a “Man-in-the-Middle” attack.
How will an SSL Certificate help you defend your website from these attacks?
The contribution of the HTTPS protocol in stopping the Man-in-the-Middle attacks derives from the concept of the SSL Certificate and the Certificate Authority’s infrastructure. The concept is based on the usage of the private key, which establishes a valid connection when it is associated with the corresponding certificate.
The question is: if there is a Client connecting to a Server, can an Attacker, who gets between them, receive the SSL certificate and successfully decrypt the data?
Well, the Attacker can definitely receive the same certificate because the last one contains the public key and the domain name which the Server sends to anyone who wants to connect to it. However, the Attacker won’t be able to decrypt the information because only the Server owns the matching private key who can decrypt the data.
So, because the Server keeps this private key secret, the Attacker cannot use the real certificate of the website. He has to use one of his own. This means that he must convince the Certificate Authority to either sign the certificate or use it as it is. Thus, if the Attacker is using a certificate that is not validated by a reputable Certificate Authority, the Client’s web browser will identify him immediately.
The Attacker may also try to forge the SSL Certificate and provide his own public key to the Client. This action will destroy the signature of Certificate Authority and the Client’s browser will display warnings about the invalid SSL Certificate.
Therefore, the specific structure of the SSL Certificate prevents Man-in-the-Middle attacks, protects your customers from dealing with hackers, and ensures the trustworthiness of your company.