[suixo]

This looks like an amazing idea, why didn't you proceed further? I would love to see something like it, that could help certify messages :)

[Faaak]

Amazing idea but very ugly per se. The thought of mixing "human semantics" with signature in an whole text sends shivers down my spine.

[jandrese]

It's pretty similar conceptually to how we sign email, except that the signature would be invisible to humans.

Of course nobody ever said how we sign emails is beautiful.