Here's an example of what I mean:

enter image description here

(It's basically the same thing as a traditional signature.)

Given I've never seen someone fail this control, it's unclear to me what real security such a system would provide. Am I missing something?

  • The problem I have with these devices is that I have no guarantee what my signature will be used for, or that it won't be copied. This sounds more like security theatre than anything else, but many organisations (including banks) like that sort of things. It's only really a problem if you can't contest it easily in case of problem (which may be the case indeed).
    – Bruno
    Commented Jun 18, 2012 at 17:15

2 Answers 2


A signature is gold standard for authenticating paperwork. Really I see this is an evolutionary artifact of progress technology. For so many years we didn't have anything better, and so it has been "grandfathered in".

I have heard of credit card companies performing automated analysis on the transaction and signature to see if it is a fraudulent purchase, but this is a very difficult problem to automate.

Personally I think signatures are nearly useless. Perhaps they are most useful as evidence to be used in court. If you clone a credit card, the only evidence of the transaction is a grainy security camera, and a signature of the transaction.


Traditional signatures are still the most widely used form of authenticity for the exchange of physical goods (think paper documents, packages, etc.) or for acknowledging an event in person. Other forms are creeping in (think chip-based credit cards, NFC, etc). This digital pad is simply a replacement to physical ink and paper and can be used to sign digital documents. Not everyone has an assigned private key.

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