: Can I digitally sign my graphic design works? Apologies in advance if I misplaced this question and if it is a silly question to ask since I'm a newbie. I want to certificate my graphics

@Bryan765

You can install GPG and run gpg -s your_document. You don't need to use a CA but your key can be uploaded to a key server and it will be certain that the key belongs to you if you have it signed in what is called a web of trust.

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@Cugini998

Yes you can cryptographically sign your work or any digital file as a matter of fact. The signing only computes a hash of the file or set of files and provides a mechanism for the user to verify that the hash is same. If the hash changes then the file has been tampered with and no longer satisfies signature. The system essentially ignores file type (a file is a collection of ones and zeroes after all).

The real challenge is that is the recipient ready to check signatures. Most likely they are not. Signing a arbitrary file is somewhat pointless if your end user has no intention/capability to verify authenticity. This is a social problem and technology can not overcome this.

If you make your own CA (Certificate Authority) then the question becomes how do I exactly know you have signed it. What is to stop me from changing your file making my own CA and signing the file? This is fine if i know you and can get a certificate to authenticate you beforehand, but if not then its pointless. This is why such things as keysharing parties exist. Problem with keysharing is that the other people you want to verify the signing for must also attend some keysharing party (not going to happen in most cases), or rely on a organization much like a official CA. (you can get a free key that is widely recognized though even in the current system)

Some formats, most notably PDF have a in-built cyptographic signing facility. So you could archive your data inside the PDF file as a attachment and have a certificate of authenticity on a page describing how to use this. But again would be highly unusual. Besides most users aren't aware of such things so even if you did this i could strip it sign with another signature and most users would be blissfully happy in ignorance.

TL;DR

Simply put, you can not overcome the social problem. Technically its easily done.

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