We help prove
human authorship

We named our company after the oldest proof of authorship we know of. Forty thousand years ago people pressed their hands against cave walls and blew pigments around them. It wasn't art. It was a statement: we were here; we made this.

HandStencil is built on this idea. Our product, ByHand, verifies human authorship through writing behavior. Not by reading what you wrote, but by following how you wrote it and the patterns that make every writer unique.

We built ByHand because the current approach to this problem is broken. Other tools read texts and guess whether a machine wrote it. That's already failing. We look at the writer instead. That way it's a simpler question with a more honest answer.