Real Ink Verifyable Signatures

So I saw someone sign a credit card slip today with a smile face and a star, they mentioned that this was a light security feature to make it real easy to tell if someone was trying to forge their signature (without seeing theirs first at least).

I thought that was a pretty neat idea, and to be honest, any excuse to legally draw smiley faces is cool in my book, but it got me thinking…

We live in a day and age where we have some REALLY good hashing functions and cryptology avilable to everyone… and signatures would be a nice place to make use of them.

Suppose you had a small application on your phone, it could generate a number between 1-100 based on a key, and what day it is, such that it would be completely impossible for anyone else to be able to know what it was or do the same, without having your key.

You could essentially have a signature that no one else could reproduce, just by writing down the correct number after your signature.

(and then my mind started thinking about how that should be a genetic implant in your hand to have a key generator , or maybe in your pen, phone, etc etc)

There is a serious limitation to it though, you could never prove that you DIDN’T sign anything, as people would just say you left it out that one time on purpose.  You could only prove that you DID sign something.

Anyhow.. i still think it would be pretty cool, and sense I’m a bit of a geek i think it would be totally worth the effort of always having the gadget on you..

And if you think.. instead of a number 1-100, if it had a database of 1000 awesome symbols.. you could just draw one of them instead.  Maybe Egyptian glyphs… hmmm

yes.. in my head i do foresee myself being extremely important, and there being a life and death situation pivoting on the argument “Greg didn’t sign this! he never would have!  You forged it just to try and save your puny rebelion!”  “Stop the execution!  I have undeniable proof!”


  1. I’ve always drawn a Duckie on the ‘lectronic pads when I had to give my signature when using a credit card, if *anyone* signs my name, it’s fraud!

  2. look at my last name….grins
    I sign backwards and yes I lost a card and someone chrged 375 dollars on it which I didn’t have to pay. The actually store all those electronic images and this one stuck out. I had absolutely no problem convincing them that wasn’t me who used the card at Radio shack

  3. I’ve worked for the banking industry for quite some time, and in any case where signature verification is needed, the burden of proof is on the RECIPIENT of the payment. If they said “oh you left it out on purpose”, you get to say, “So one of your employees failed to check to see if the verification number was written?”

    …because it’s on THEM :3

    I love putting a mountain-like jagged scribble where they want my name to go. All of my debit cards read “CHECK IDENTIFICATION” on the sigstrips though.

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