Blackbird the challenges lie with detecting a forgery and in creating mechanisms to thwart forgery.
This was basically my last job before retirement. Of course, we were not concerned about receipts but mostly currency and security documents.
As mentioned there are many security features embedded in documents. The fact that an AI can make something that looks genuine is not a problem. I could do that 20 years ago. Counterfeiters have been doing it forever. It’s the things you can’t see that will give it away. You just need the right equipment to verify the document.