What Is a Root CA Certificate, and Where Can I Use It?

Among the various digital issues today, online security and privacy are the prime ones. When you search for something online, you subconsciously give away a lot of information to the web.

Now, lucky for you that Google marks the website as secure or insecure based on its SSL certificate, or all of our crucial data would easily fall into the wrong hands. An SSL certificate is the sole parameter that defines the website’s security. However, its foundation is something else: the Root CA certificate.

If a website is insecure, you might have encountered the error “this site may be insecure.” It is a common error that Google shows you when a website is insecure. This thing questions the SSL certificate, which goes back to the intermediate certificate and points back to the CA root certificate.

Online security is crucial, but what is the root CA certificate, and where can you get it? We will briefly discuss everything in the article. Just keep reading!

What is a Root Certificate?

The root certificate is the major or, should we say, the primary node of the entire public key infrastructure. It serves as the fortress from where all the legitimate commands of the infrastructure originate.

To understand the root certificate, we have to understand the certificate chain first. Whenever a user searches for something and clicks on a website link, the browser checks the SSL certificate of that website.

By default, every machine has a root store containing all the necessary root certificates. When the browser checks the obtained SSL certificate with the root store, the root store returns a signed version of the SSL certificate if indeed it is a legitimate one.

The CA root signs the SSL certificate and returns it. When the browser sees that the certificate is signed with the private key, it opens the website in front of the user.

Behind the scenes, the browser is following the certificate chain to check if the SSL certificate is legit. The structure of the chain is as follows!

CA Root Certificate Vs. Intermediate Certificate Difference Explained

CA Root Certificate

The root certificates are the pivotal elements of the public key infrastructure. They are self-signed by their CAs. As a CA is a certified authority, all the SSL certificates are under a specific CA. As the root certificate is one of the pivotal elements of the PKI, it needs to be protected at all costs.

Intermediate Certificates

The second key entity in the PKI is the intermediate certificate. The cool thing about the intermediate certificate is that it directly falls between the root certificate and the leaf certificate (SSL certificate), and there is a reason for this.

You see, the root certificates are too crucial to get compromised. As they are the perfect embodiment of trust, they must be protected at all costs. Hence, to insulate them, the certificate authorities issue an intermediate root.

So, whenever an SSL certificate is required, the intermediate root signs it, and it becomes legit. The intermediate root is signed with the private key, which makes it trustworthy.

Now, there doesn’t need to be only one intermediate root between the root and SSL certificates. There can be more than one intermediate certificate in the chain, too.

What Constitutes a Trusted CA Root Certificate Authority?

On the web, trust is classified as Social and Technical Trust.

Technical trust is always dependent on Social trust. However, various things need to be fulfilled to be a trusted or legitimate Root certificate authority. For example, audits, public scrutiny, and other strict requirements.

It is obvious that if you are a new Certificate Authority (CA), you will start issuing certificates before getting verified. The verification process is simple! You will get verified when your SSL certificates are used for enough time without any issues.

Once this happens, you will get the roots added to the root stores of various operating systems like iOS and Android. Thus, you become a trusted root certificate provider.

By definition, a trusted root certificate is a particular type of X.509 digital certificate. It can be used to issue other certificates.

What Is the Lifespan of Root Certificates?

If you get the message, “this site may be insecure,” it can be because the certificate’s lifespan has depleted. Usually, this happens only in the case of SSL certificates that are mis-issued or have security issues.

In the case of the root certificate, it is doubtful as the age of these certificates is more than the SSL certificate. An SSL certificate has a lifespan of 2 years, whereas the lifespan of a root certificate is 25 years or more.

How Does the Browser Know if the SSL Certificate Is Legit?

Well, if the root certificate has signed the SSL certificate, it is enough to prove that the SSL certificate is legit. But, the browsers check some of the basic points to assure its legitimacy. Here are some of those points!

1. The browser checks the validity date.
2. It is checked if the certificate has ever been revoked.
3. Digital signatures by the root CA are verified.

How to Get a Root Certificate From CA?

Well, you do no need to download the root certificate on your machine. Why? They are already pre-installed on it; secondly, they come stored in the root store of the operating system.

So, the system will warn you whenever you get an untrusted SSL certificate. Moreover, the root stores are also auto-updated with the new CA certificate file. So, no need for a manual update.

However, if you want to undertake the root certificate download for any reason, you can do so from the service provider’s support page.

Final Words

So, this is all about the root certificate! It is the critical element of the public key infrastructure that ensures the security of the user data. However, as the root certificate is a crucial element, it must be protected in all cases. Thus, an intermediate certificate is connected to it.

It is done to ensure safety, as the intermediate certificate can sign the SSL certificate on its behalf. The root certificate has a longer lifespan than the SSL certificate, which is pretty evident as it is a governing entity.