Docs

What this is

A signed record of how a piece of writing was written.

You are a human, and you want to write something: an email, a reply to a chat, or maybe an essay. As of June 2026, the chances of your audience assuming that you did not write it (you asked an LLM to write it for you instead) are quite high — particularly if you dare to use an em-dash. And you will find that quite annoying.

And, disturbingly, there is probably nothing you can do to actually prove that it was you who wrote it. I cannot think of anything that will not be possible to spoof by a sufficiently determined LLM.

We can, however, help you plant a stake in the ground and claim authorship, and we can do it in a way that would be slow and cumbersome for a spoofer to fake. We do not prove that you wrote it, but we do prove that you really wanted people to think that you wrote it.

What we do

This is what possiblymadebyahuman does, by recording your writing signature: the delay between keypresses, the backtracking, the long pause where you got up for coffee.

We then sign the pattern of your writing with a hash chain into a short URL anyone can open. Only the shape leaves your machine; the words stay with you. You can also bind the finished text to the record, by keeping a content-blind fingerprint computed on your own machine and then thrown away, so a reader can confirm that the copy in front of them is the one you signed.

What a reader sees

The statistics of the writing process and a unique signature. The reader can then check if the text they received actually matches the signature of your text. Crucially, this is all done without actually storing your text.

How you would fake it

Write a program that types the way a person does, with the hesitations, typos, second thoughts, and pauses, and let it drive the record. The record is the timing, so the forgery has to run in real time: faking a twenty-minute essay costs your program twenty patient minutes, and faking a week of work takes a week. Cheating stays possible, and stays as slow as writing the thing.

So it is not that hard. It’s just annoying and sad enough that we hope that actual humans generally won’t cheat.

This was only partially written by a human: https://possiblymadebyahuman.com/8MxUYwiQ3q