Well, it's not like my card is hooked up to the internet for everybody to try and log in.
PIN isn't particularly vulnerable to brute force anyway, as number of failed authorisation attempts is strictly limited to something like 3, and a fraudster has to risk capture by being physically present at each attempt or 'trying out' a stolen card, and having their face recorded on cameras.
I haven't seen any advantages for using 6-digit or larger "passwords" for that particular scenario. The largest practical security benefit seems to come from enforcing random PINs and not allowing to choose - since the banks that allow to choose are vulnerable to "dictionary attacks" of trying the user's birthday (obvious from other stuff in a stolen wallet) and stuff like 1234.
Now, checking "signature" instead of chip&pin, now that's an example of blind trust.
> Now, checking "signature" instead of chip&pin, now that's an example of blind trust.
If even. I cannot find the original report, but there was a guy who tried all kinds of weird signatures including "I STOLE THIS CARD" and it only took purchasing 3 most expensive TVs and signing "NOT AUTHORIZED" for someone to question him.
Interestingly, the signature could be argued to be better in some cases:
Under British law, a forged signature is never your fault, and the bank/merchant/card processor are liable (I can't remember exactly which, I think it depends). One of the reason that card issuers were so keen to switch to Chip&PIN/EMV is that the liability was turned over to the user. As they thought EMV was "unhackable", always a dangerous thought, it was always assumed that the user had told someone their PIN. It wasn't until relatively recently that the Cambridge University security research group showed that it was crackable, and the banks/etc started taking liability in some cases again.
>> One of the reason that card issuers were so keen to switch to Chip&PIN/EMV is that the liability was turned over to the user.
Not really true.
The main reason was the switch in liability to the merchant, if the merchant accepted a transaction without using EMV and PIN.
AFAICT the Cambridge research isn't really that relevant, it doesn't really give you practical attacks, and it's not so much a crack on the chip security itself as it is a piece of Man-In-The-Middle hardware (IIRC, haven't read it for a couple of years).
Under UK law, with a credit card (debit is different), the liability is never with the user. The bank may claim that it was obviously you that did it, or that you gave away your PIN, but where credit is concerned they legally have to refund you the money pending an investigation.
Debit is less strongly protected and comes under banking rules and guidelines, and if you report unauthorised activity as fraud they will usually still take your side.
--edit-- I'm not trying to say EMV is bulletproof, nothing is bulletproof, but the primary method anyone's going to use to get your PIN is still social engineering, or possibly some sort of compromised terminal hardware, which they'd have to make from scratch because accredited devices disable themselves if they detect they've been tampered with.
I have no doubt you're right, and the banks absolutely should not reject fraud reports based on PIN.
I've had a read of the first paper there, the nopin one, and it reads like a really preventable flaw in the IAD, which (as it's issuer specific) could be very easily fixed without the involvement of terminal vendors. I agree with the conclusion that the TVR is a flawed concept though, I had always assumed (never having worked directly for an issuer) that there would be enough data in the IAD to marry up the terminal and card perspectives on what had happened.
And on the second one I'd be the first to agree that SDA and offline-plaintext PIN are a bad idea, I could have told you that when I did my first implementation in 2001!
--edit-- I had actually assumed that by now the cost differential between SDA/plaintext and DDA(or CDA)/encrypted cards would be so small that nobody would use the SDA cards any more. Guess I was wrong!
Actually that's subjective. If the overall fraud is lower then (potentially, I'm sure this doesn't actually happen) fees, charges, interest rates etc could be lower for all users, therefore they would benefit from security that lowered the overall cost of fraud and the overall number of incidences of fraud, even if individuals that directly experience fraud are worse off.
Yes, but "security" isn't "overall cost", its about risk. I am more secure, even if my expected cost is higher, if I don't directly bear any risk of unconsented loss even if the overall incidence of fraud is higher and I am paying a distributed share of those costs.
I was once refused a consumer credit application for a kitchen appliance because I'd forgotten to sign the back of my credit card. I had a passport and a photo driving license on me at the time but because there wasn't a signature they "couldn't be sure" it was me so they refused to process the application.
I signed it in front of them (which matched my passport signature BTW) but was politely declined as they'd seen the card unsigned.
Another example of security policy getting in the way of actual security.
I had a slightly similar experience: I forgot to sign the back of my card, but the person just asked me to sign it and then made sure it matched my signature on the receipt.
You could have stolen the card of an homonym, so it kind of make sense. Printing a photo of the owner on credit cards would go a very long way and isn't too expensive, but this is a very high inertia industry.
PIN isn't particularly vulnerable to brute force anyway, as number of failed authorisation attempts is strictly limited to something like 3, and a fraudster has to risk capture by being physically present at each attempt or 'trying out' a stolen card, and having their face recorded on cameras.
I haven't seen any advantages for using 6-digit or larger "passwords" for that particular scenario. The largest practical security benefit seems to come from enforcing random PINs and not allowing to choose - since the banks that allow to choose are vulnerable to "dictionary attacks" of trying the user's birthday (obvious from other stuff in a stolen wallet) and stuff like 1234.
Now, checking "signature" instead of chip&pin, now that's an example of blind trust.