How does a Code Signing Certificate Work?

Code Signing Certificates are commonly used by software developers and publishers to provide unique identity through digital signature for various files such as applets, macros, plug-ins, codes, and other executable files before publishing on the internet. The main reason to do so is to confirm the integrity of the software, as Operating Systems, Software Applications, Mobile devices, and networks ask for a trusted digital signature for the safety of their users.

However, the method for Code Signing is quite similar to SSL/TLS Certificates where a pair of cryptographic keys (one Public & other Private) is used for the identification and authentication of the code. Again, below are some of the steps, which are essential to follow before getting a Code Signing Certificate.

The Process of Enrolment

Whenever you apply for a Code Signing Certificate, a private and public key pair is generated. The public portion is provided to a Certificate Authority along with all the required documents for proving the organization or individual’s identity. Once the Certificate Authority authenticates and verifies the provided information, your Code Signing Certificate is issued, which includes the full name of the organization and a public key. Once it’s issued, you can use it to sign your software, code or content throughout its validity period, ultimately allowing everyone to download your software without any error or warning message.

Deployment

• Firstly, software developer or publisher uses Code Signing Certificate for signing a script, code, software or any other executable file.
• Once the digital signature is attached to the file, a hash mark is made using a mathematical hash function (irreversible method of cryptography) to create a hash value or digest that can’t be duplicated.
• The content is made public as it publishes on a website or mobile network.
• Finally, the user downloads the software or application, and the user’s system uses a public key for decryption of the signature.

Root Certificates

No doubt, certificates gives an assurance that software or any other executable is safe to download. But you should be aware that a signing key can be created by anyone.

To overcome such situations Root Certificate (a public key certificate which identifies a root certificate authority) is issued, which includes a signature of the globally known Certificate Authority.

In other words, you can say that Code Signing Certificates are like a family tree where Root Certificates play an essential role. It let users determine whether the used Code Signing Certificate is trustworthy and accurate by allowing them to trace the “chain of trust” back to the original signing authority, which could be any globally trusted name such as Microsoft or Apple.

Video: Understand What is Code Signing Certificate & How it works