Code Signing Certificate FAQ

Frequently asked questions about code signing certificates

How to fix the error message "One of the countersignatures is not valid. The file may have been altered."
The algorithm SHA1 has long since been deemed too weak to use and has been considered deprecated for quite a few years now. If you are seeing the message...
What happens when my Code Signing Certificate expires?
Code signing certificates are valid from 1 to 4 years. When your certificate expires only your ability to create new signatures is affected, past signatures...
The truth about SHA1, SHA-256, dual-signing and Code Signing Certificates
**PLEASE NOTE: As of May 30th 2020, SHA1 timestamping is effectively deprecated as the SHA1 roots have expired. Use only the SHA256 timestamp server from ...
What is a timestamp?
Put simply, a timestamp records when a signature was created. Because all code signing certificates expire it is important for any software verifying a digi...
What is this "FILE is not commonly downloaded and could harm your computer" message? (SmartScreen)
SmartScreen is part of Windows Defender. It is a reputation based filter from Microsoft that Windows and many modern browsers use. You can get the details h...
What are the requirements to obtain an OV or EV code signing certificate?
Documentation Requirements   A code signing certificate is an identity certificate. Because of that there is a validation process through which you will h...
Why is Internet Explorer Required to Complete a Code Signing Certificate Order?
Trust us, it isn't because we like IE! The truth is, it is the only browser that reliably supports private key generation on the customer's...
What is the order procedure for a Code Signing Certificate?
The order process consists of two steps, placing the order (filling out a short form at https://www.ksoftware.net/code-signing-certificates/) and validating...
What browsers are supported?
The only time a browser comes into the equation is at order and collection time. Users do not need to install the certificate for it to change the Unknown P...
Can Comodo/Sectigo Code Signing Certificates be used for kernel mode driver signing?
Yes! See our first FAQ question for the details.