X.509 Certificates: All there is to know ( And beyond! )

x-509-all-there-is-to-know-techxchina-coverWhen we talk about certificates, they are these printed papers which shows that you are certified to do a certain task. Certificates basically show that the certification is legit and verified and have significance in one way or the other.

Similarly, digital certificates are the certificates that the computers and other electronic devices use to show that the information is legit and can be verified. Just as it is with printed certificates, the digital certificates too are issued by a trusted company which has the name of the certificate holder as well as the date on which the certificate was issued.

There are thousands of certificates that the computer system uses to make computing more secure and reliable. The digital certificates also help sets standard in the computing industry.

There are millions of digital certificates out there. And, one of them happens to be X.509 certificate. So, what is X.509 certificate? Let’s find out!

Basically, the X.509 is a certificate that contains info about the person or organization to which the certificate is issued to as well as the body that has issued it. Usually, it is the Certification Authority which issues the certificate.

The X.509 certificate contains a lot of information (and much more than what is listed here) but here are the basics:

  • Version: Which version of the X.509 was applied to the certificate
  • Serial Number: Which is unique and distinguishes it from other certificates
  • CA Name: has the certificate authority name in it
  • Expiry Date of the certificate: Digital Certificate do expire and need to be renewed every now and then
  • Public Key: the key of the certificate receiver

And here’s a fun fact: many of the SSL certificates that we apply to our websites to make it https from HTTP are in fact X.509 certificates.


Are certificates really effective and worth your time and investment?

The HCI Researchers evaluated the use of certificates with browsers and through multiple studies found out the effect of these certificates were indistinguishable from placebo.

But they are not without its benefits. In fact, many of the online systems use X.509 trusted certificate as the base of the security.

There are many instances in which the entire server have broken down when there is no X.509 trusted certificate or when the certificate has expired.

Back in 2008, one of the largest Japanese Airline, the Nippon Airways faced a huge computer outage just because there was a minor problem related to certificate authentication. It led to the terminates not being able to communicate with other computers connected in the network.

It’s not the large systems that fail when the X.509 trusted certificate fails. Smaller systems and websites fail to load too when the certificate fails or is invalid. I faced a similar issue just a few days ago with my own website.x-509-all-there-is-to-know-techxchina-certificate

The solution to it was quite easy as only the certificate had to be renewed. However, the loss due to the failing of certificate can be in either tens of dollars or as large as millions of dollars.

The computer systems use X.509 trusted certificate which is issued by a CA to enable transfer of file and data from one server to the other.

Also Read: Disappointing! GATEHUB starts charging huge Deposit Fees

In case of X.509 certificates, various cryptographic functions are employed. Here’s a simple diagram showing how the functions are employed in the X.509 certificate.

X.509 Certificate Diagram


So, we have the figure above which we have a certificate which isn’t signed and contains the User’s public Key as well as the user’s ID. First, we apply the hashing function which hashes the certificate. From which we get the hashed certificate.

Note: Hashing functions are used to condense any message be it a single 1-page document, or a novel or a movie or the entire Internet into a fixed size. It is usually for subsequent signature by a digital signature algorithm.

And when the certificate is hashed, it is looked up be the Certification Authority (CA) who encrypts the certificate. The encryption is done by the CA using his/her private key. And then, we have the encrypted certificate.

Finally, we have the signed certificate which has its own ID which is unique to the specific certificate. The certificate also has a date of expiry as all the digital certificates do expire. The certificate also contains the public key of the CA.

Using the X.509 certificate, we can gain trust from our customers while having our system more reliable and secure. The X.509 certificate is one of the basic digital certificates that is used to encrypt and used for information security throughout the globe.


Please enter your comment!
Please enter your name here