Ask HN: Why isn't there something like Let's Encrypt for document signing?

electronic document signing as a concept is covered by many software patents

if you started your own product doing it you would get sued by DocuSign and friends, and they have lots of money for lawyers

so quite hard to disrupt their monopoly

Secure communication implies three things: 1. the involved parties verify each other's identity, 2. communication is not compromised 3. the communication isn't spied on. The problem with self-signed certificates is that browsers can't establish (1), so they complain. Let's Encrypt really only solves the problem of browsers complaining, but it doesn't verify the domain owner's identity (eg. no credit card check).

I think document verification should be more stringent: you want to be sure whoever signed a document is who they claim to be and have the authority to do so, not just that they owned some domain and got a free certificate.

we have it in EU, IIRC eIDAS directive. Anyone in EU can digitally sign and verify documents

Document signing is about verification of authenticity of origin of author. LetEncrypt does not do this, not even for websites. I can get LE certs for millions of end-points I do not own due to the way many cloud providers abuse DNS and sub-domains. Some people do this day and night as a way to make a buck on the side from bug bounties. One of them I will never forget as he adds pictures of cute puppies to corporate websites.

The only open source answer I know of is probably not what you want as it would require every party to participate and would require a little setup thus not making it widely adopted. Documents can be signed with GPG but this alone is useless. Every party involved would need a way to publish their public keys and prove that each party actually created said keys. This to me implies inclusion of a public notary in the process. None of this matches your requirement of widely trusted not to mention the added friction. The original method of getting EV certs proves that people will not do this. It used to require a notary Now I can just give a Dun & Bradstreet number and some money to get one.

To my knowledge there is no widely trusted document signing system nor do I expect that to become a thing unless a service that people already use started implementing what I described above. I could see one or more banks offering a service like this. Many already have public notary services.

There are services like Docusign and Docushare as others mentioned and they are used and abused by lawyers and realtors day and night. I honestly do not see any added value by these services beyond being lazy-friendly. If I log in using my email address and click a button that adds a cursive signature that I did not create, that is not really proof of anything. Anyone that could intercept my email could impersonate this. I expect these services to be legally challenged and dissolved in the future for lack of attestation, especially when a future high profile case involves powerful political and corporate persons having to prove they did not embezzle money. Covid made them super popular but I was very surprised to see the legal documents I could get away with clicking in signatures with no other evidence it was me that did this. I am not a lawyer but I am not sure that matters in this case.

In my opinion if you have important documents that you want to prove were signed by you then my suggestion would be to see if your bank offers free public notary services and have them notarized. The page containing the signatures and the notary/bank information can be scanned as part of the document set.

[Edit] I should add that some of the bigger banks will only offer free notary services if the account holder has one of their special accounts. They usually have the name Premier or Priority or some other glorified name.

Don’t forget the lobbyists. They have lots of money for them, as well.