Show HN: Let's Seal – Let's Encrypt for document signing, free and self-hosted

A new project called Let's Seal is pitching itself as the free, open-source answer to paid document proof services — basically, a way to show a file is real, hasn’t been changed, and existed by a certain date. The big promise is simple enough for non-lawyers and non-cryptography nerds: seal a PDF, image, email, or other file, and anyone should be able to check it later for free. The vibe from the launch? Curious excitement with a heavy side of side-eye.

Some commenters were genuinely into it, with one early explorer saying they were “excited to see where this goes” — before instantly finding a broken discussions link. That tiny 404 became the perfect Hacker News mood setter: cool idea, but the internet never misses a loose screw. Then came the sharper reactions. One commenter threw the biggest grenade by calling it an “invented standard,” which is basically catnip for tech people who distrust anything that sounds too new, too neat, or too self-defined. Another zoomed in on the real make-or-break issue: trust. If this service says a document is authentic, why should a company, judge, or anyone else believe the people behind it?

And then there’s the legal reality check, which may be the thread’s most deliciously deflating twist: one commenter noted that courts still often accept paper-signed, scanned PDFs anyway, making all this extra proof feel a bit like bringing a spaceship to a bicycle race. So while Let's Seal wants to be “Let’s Encrypt for document signing,” the crowd is split between “finally, useful public infrastructure” and “nice pitch, but will this matter in the real world?”