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Comment by pki | Hacker News Reader

It's a shame that chip and signature is used in the states though..

The problem with chip and pin is:

A) you want me to type my pin into a compromised device, the pinpad at the pump

B) you expect me to remember seven pins, I carry seven credit cards (yes that's excessive) and each should have a separate pin for security, right?

No, an actual chip should be secure enough to make skimmers pointless. However, we somehow desided to built and roll out a completely insecure chip system.

Ex of a simple and secure system. cc shows transaction cost, user clicks ok on the card. Card digitally signs a transaction with time stamp, vender ID, and amount.

Want safe online transactions, add a USB dongle or Bluetooth.

Do you have a reference for why it's "completely insecure"?

I think the idea is that it's reasonably-secure against skimmers taking your data and then re-using that data in another session or location when the card is absent.

But it won't save you from a compromised point-of-sale system that lies to you about how much you're paying or which commits fraudulent transactions while the card is still in the reader.

Which is why the amount should be displayed on a display embedded in the card itself. The control for authorizing the transaction should also be part of the card.

Now, if only we carried around a device that included a display and some sort of input mechanism, plus a near-distance communication chip...

(Ok, if the device is a general computing device, a special secure operation mode might be needed for this sort of use case, one which can't be subverted by normally installed software, but still...)

> special secure operation mode might be needed for this sort of use case, one which can't be subverted by normally installed software

Now people will complain that "the app doesn't run on their rooted, bootloader unlocked, jailbroken phones"

No reason why it shouldn't. This is not DRM, is your own credit, secured on your behalf. It should just be resistant to software based tampering by default. Specially, as I said, "normally installed software". If you can make sure that rooting your device requires a explicit knowledgeable user interaction (say: rebooting, erasing all data, then re-keying your device to your bank account somehow - in person visit?), then I see no reason why you should be prevented from changing the secure operation mode code itself or building your own compatible device.

I mean, you can mod the brakes on your car if you really want to, at your own risk. What is a bit strange is when your media player can affect your brakes without you even noticing. Same principle here, less lives on the line.

I believe he's referring to the current scan card + signature combo, which is very well known for being insecure because you t can be man in the middled, and the card is transmitting enough of it's information to duplicate the card if that data was captured by a skimmer.

the pin is useless without the chip. it's only one half of the something you have + something you know.

What is the point of the sigature? Mine never look even close to the same. Is this a serious security mechanism?

If you're not going to do chip and PIN (and you should), why not just chip and nothing?

When working a retail job I once (and only once) saw a credit card with a photo of the person it was issued to on the back. It was also about the only card I really bothered to check ownership on because signatures were useless.

Thankfully we've now got chip & pin, completely removing the need for minimum wage retail staff to verify ownership of credit cards.

Is this a serious security mechanism?

NPR's Planet Money recently did a story on the signature in CC payments. The answer seems to be "not really".

Here it is, Planet Money Ep. 564: The Signature (16:20)

"Today on the show: the signature. It's supposed to say, "This is me." But where did the idea come from? And why are we still using it? We consult a rabbi, a lawyer and a credit card executive."

http://www.npr.org/sections/money/2014/08/29/344034815/episo...

The signature is just a bit of evidence to check if you dispute a charge. It isn't a 99.99% key like in encryption.

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