Is it possible to hack an SSL certificate?

If you have an SSL certificate installed on your site, you may have wondered if they are quite as infallible as they’re made out to be. For instance, can an SSL be hacked? The short answer is that while it is technically possible to hack an SSL, the probability of it happening is incredibly slim. 

In this article, we’ll be going over why SSL certificates are incredibly difficult to compromise, as well as how when somebody thinks their SSL has been hacked, it’s more than likely due to another issue. After that, we’ll briefly cover ways you can strengthen your SSL certificate’s effectiveness for added peace of mind. 

First, let’s address a common misunderstanding about SSL certificates.

SSL certificates don’t protect your site from getting hacked

SSL certificates enable encrypted connections between a client and a web server via the transport layer security (TLS) protocol. In everyday terms, a client is a web browser and a web server is a place where a website is hosted. An SSL ensures that any communications sent over this connection can only be read by the sender and the recipient. Nobody can intercept a message while it’s being transmitted over an encrypted connection.

That is the extent of an SSL certificate’s capabilities. It protects communications, keeping them private from prying eyes. It does not protect your website from getting hacked. While SSL certificates are an incredibly important part of website security, they’re just one single element. You can’t just install an SSL certificate and call it a day, expecting your website to be completely safe.

Think of it this way, if you had a house with several exterior doors, it would be silly to lock only one of them and think that you’re protected from all manner of intruders and unwanted visitors. By having an SSL, you are simply locking the door of your website that protects communications between your site and a visitor’s web browser. To completely protect your site, there are myriad other doors that need to be locked, such as malware and virus protection, as well as password hygiene.

For more information, check out our blog post on protecting your website beyond SSL.

The hackability of an SSL

Now that we’ve covered what an SSL actually does, let’s talk about the likelihood of an SSL being hacked. We mentioned earlier that it isn’t impossible, but the chances are very, very small. One person couldn’t do it on their own. Even with the strongest supercomputer to assist, it would take an unfathomable number of years.

To explain why we’ll need to get a little bit technical and explain how encryption and decryption work beyond just rendering data unreadable. Specifically, how current SSL certificates using the TLS protocol renders information unreadable through the use of keys and 256-bit encryption. 

First, let’s talk about how encryption works in its most basic terms. A classical encryption key substitutes letters of the alphabet with alternative letters. A good example of this is the very first of these: The Caesar Cipher, aptly named after Julius Caesar who used it himself in private correspondence. 

It works by replacing each letter of the plaintext with a letter a given number of positions down the alphabet. This given number is the key to unlocking the code. For example, if the key is three, each letter of the alphabet would be shifted forward by three. So A would be replaced by D, B with E, and C with F. 

If someone wanted to send a letter to a friend and wanted to ensure that nobody else could read it, they could scramble the normal text of the letter to ciphertext (encrypted text) by using a cipher and key, such as the one we previously mentioned. The recipient of the letter, who also has the same cipher and key, can decrypt the letter once they receive it. The cipher and key must be kept secret from everyone but the sender and the recipient in order for the message to remain truly encrypted.

Modern encryption works largely on the same principle, but on a much larger scale. With TLS 1.3, digital messages sent between a browser and a web server are encrypted and decrypted using a 256-bit private key. 256 bits refer to the length and strength of a key. To crack a private key by brute force, you would need to figure out up to 2×256 different number combinations. That’s about 115 quadrillion possible combinations. That’s a lot of combinations.

So how hard would it be for regular humans to figure it out? Pretty much impossible. You might have a better chance if you happened to be a supercomputer with millions of years to spare. Some people think quantum computers might have a fighting chance one day, but the ones available currently don’t yet have the capacity. 

So, all things considered, someone hacking your SSL certificate isn’t something you need to worry about.

How to strengthen your SSL

While it’s unlikely that your SSL certificate will be hacked, there are other ways an SSL can be compromised. Ensure your SSL has a fighting chance by doing the following:

• Protect your private key: Hackers won’t even need to guess anything by brute force if they somehow get their hands on your private key. If you suspect that your private key has been compromised, make sure to get your SSL reissued as soon as possible. 
• Disable older versions of the TLS protocol: An SSL certificate is as strong as your website server configurations. Make sure your settings support TLS 1.2 and 1.3 and disable older versions that could leave you vulnerable. You can check your settings by using the Qualys SSL Server Test.
• Stay on top of SSL renewals: If your SSL certificate expires before you get the chance to renew and replace it, your website could be left temporarily vulnerable to man-in-the-middle attacks. Keep an eye on your SSL’s expiration date and be sure to begin the renewal process several days in advance.

Wrap up

Hopefully, you come away from this article with a better idea of how SSL certificates work and the scope of their capabilities. Although an SSL is nearly impossible to hack, it’s essential to take the necessary steps to ensure yours won’t be compromised in the future. And remember — never depend on an SSL to take care of any web security needs beyond creating encrypted connections. 

If you’ve been thinking about getting an SSL for your website, check out the range of affordable SSLs Namecheap has to offer.