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Are Signature Pads Dangerous to Privacy?
WildHunter asks: "While making a foray into a local retailer today I paid using a credit card and was asked to sign a paper receipt on top of a digital pad. Being cautious I asked what it was for and I was assured that it was 'fully secure and safe to use'. Being a typical paranoid Slashdotter I offered to sign off of the pad but refused to sign on the pad. Was I over reacting or can someone back up my paranoia with some facts?" Think about it, some deceitful vendor has one of these, sells you something, gets your signature, and can then ring up loads of charges on your card using a digital copy of said signature over, and over, and over... you get the idea. Do the current crop of signature pads prevent against this and other similar kind of deceit?
Think about it. All the retailer gets is a digital copy of your signature. Now, they could conceivably sign your name to contracts with them and such. But in order to actually sign your name, the person with the copy of your signature would have to actually write it out with a pen. Now, even the most braindead clerk would get suspicious if you had to use a stencil to sign the credit card receipt.
Yes, they could learn your signature from digitial printout, and if they're adept enough at forging, could do it that way. But they could do exactly the smae thing with old fashioned receipts (making copies of the receipt if necessary).
In addition the credit card companies do maintain large anti-fraud departments to investigate this sort of thing (as under US law, you'd only be liable for up to $50 of the purchases the retailer would make without your actual signature; it he buys a brand new rig from AlienWare with your signature, several grand will be eaten by AlienWare (which doesn't help their relationship with the CC) or it gets eaten by the CC. Either way, they see a pattern of people who have transactions disallowed, all of whom made purchases at the same store, and the retailer gets in big trouble.
There are more important risks with CC's.
I don't trust them because I don't know if they're recording a bitmap or vector/spline data. The former is okay, but the latter, if intercepted, can be used to make an infinite number of unique-looking but valid signatures. So, I usually make swirls with a fingernail while I sign, making a valid paper signature and a cloud of noise on the screen, since the pad can't tell which of four moving coordinates is the real active one when two different points are pressed at once.
I've only ever had one merchant actually look at the screen and ask me to sign again. (He thought it was the unit's fault.) The rest seem to believe that the pad is checking my signature, not just recording it.
Says the RIAA: When you EQ, you're stealing bass!
Digital signatures can be used by less-than-ethical sods just like your credit card number by the same people. Make sure your credit card company has fraud protection and be done with it....
This is similar to the people who will willing give their credit card to a person behind the counter but refuse to shop online because 'it isn't secure enough'..... Get over the paranoia and get on with your life... it is too damn short to take up your time with menial crap like this.......we are from the government - we are here to help...
There is nothing wrong about being paranoid about such things - but they are SO easy to fool! When I encounter one of these things I merely alter my signature! Not just a little bit - alot!
So - they may have a copy of my signature, but not one that would standup under examination, which beg's the question of what good is the signature system if the vendor doesn't LOOK at the signature on the card in the first place!!!
Have you compiled your kernel today??
I'm really not sure where your concern is... If you are a credit card fraud victim, it doesn't matter if its a perfect digital signature or if its a handwritten one. You report both instances to your credit card company. I'm pretty sure they would clue-in if they noticed that all of a sudden you went on a $10,000 shopping spree and digitally signed your receipts exactly the same way every single time. (Again this is if you report it.) BFD, with these devices you can get a perfect digital signature. Well last time I checked, we are not digital machines. We are incapable of doing anything perfectly the same twice--including signing our name.
I would be more concerned with the fact that these stores store our credit card NUMBERS, or when you order something over the phone (who knows if they aren't writing it down while typing it in?), or the clueless SSL "secure" websites that email you a confirmation with your CC number. Oops. I probably just gave you some more reasons to add a 3rd lock to your windowless house.
I was one of those paranoid customers whenever I bought something from the store, and I disliked having to allow customers to use the pads, for several reasons:
You can guess a lot by how someone signs their card, and having the card in hand allows you to verify the pattern of hand movements for the signature, as well as check expiration date, holograms, etc. With the self-swiper, the customer retains the card at all times. Sure, you can watch the hand movements and compare to the signature if you get a glance at it, but regardless, most people put their card away quickly and furtively, triggering mental red flags, and then get pissy if you ask "Sir, may I see the card and a photo ID please?". So you lose either way.
Secondly, the company would have a perfect digital record of the signature. Note that I said "company", not "store". While it's true that signatures could easily be forged from paper receipts, having a single giant database of signatures presents a much more tempting target, and a much greater reward should it be compromised. Keep in mind that Office Depot is the same company that has all their "locked-down" in-store kiosks brag about the need to enable unsigned ActiveX controls, so I'm not the most confident in their data security.
This annoys me as a customer of other stores, too. "See ID" means nothing if the retailer never gets a chance to see it written on my card.
The world of credit cards is rife with fraud and incompetence anyway. Gas stations and convenience stores are the worst. (I was recently in a gas station where the clerk told me, "Well, your signature matches, so I won't ask for your ID." Gee, thanks, lady.) And they're as obsolete as cheques -- we won't be remotely secure until we have smart chips in every card and deprecate all legacy swipers -- but I'm not sure if being secure in my identity can make me feel more secure overall. There are good reasons to keep the anonymity of cash around.
Note that I wanted to use em dashes (— HTML character entity) in my penultimate sentence, but I guess Taco has decided to disallow the ampersand escape and further muddy the waters of HTML. Way to go, guy. Is it too complicated to equate with the space character in your joke of a "lameness filter", instead of restricting those of us with US keyboards to ASCII-7? I notice you've already made an exception for &.
TO BUY A NEW CAR WOULD MAKE YOU SEXUALLY ATTRACTIVE.
Being a typical paranoid Slashdotter I offered to sign off of the pad but refused to sign on the pad.
What's the point? Now all they need is a half-decent scanner and they get the same result - a digital copy of your signature.
Was I over reacting or can someone back up my paranoia with some facts?"
You were overreacting.
Think about it, some deceitful vendor has one of these, sells you something, gets your signature, and can then ring up loads of charges on your card using a digital copy of said signature over, and over, and over...
How is this something which can't be done with a photocopying machine and some scissors? And why would the person "ringing up loads of charges" care if the signature matches or not? It's not like vendors have a central database of signatures that they check against. At best they check against the signature on the back of your card, which they can only do if you're in person, in which case you can't use a digital signature anyway.
Do the current crop of signature pads prevent against this and other similar kind of deceit?
Maybe your misconception is what the signature pad does? Signature pads merely record your signature. They don't check it against a central database or anything. Even if they did, this wouldn't be subject to defeat as long as you witnessed the person making the signature.
Or maybe your misconception is over who is responsible for fraudulent charges? A credit card purchase is simply a contractual agreement to pay. If the purchase is fraudulent, the merchant loses. Not the credit card company, and not the owner of the credit card (except for up to about $50 in some cases where the credit card was stolen). If your credit card wasn't stolen and the charge wasn't made with your permission, you're not responsible for the charges. Period.
So what does a signature do to protect the merchant? It does two things. One, it allows the merchant to check the signature against the back of the card. Two, it gives the merchant a record of the contractual agreement.
Will a judge render a judgement for the merchant in the case of the merchant forging a signature? It's possible, but there are a number of things against it. One major reason is that when a merchant gets too many chargebacks, they are generally dropped by the merchant bank. So the amount of money you can steal before you get caught is relatively low. Then, on top of that, a judge would generally take a digitally scanned signature as lesser weight than a regular one. Finally, if you can subpeona the original signature from which the copy is made and show that they are identical, then you have a slam dunk case, and the merchant will probably wind up in jail. Besides, a signature can be forged just as easily with a handy dandy photocopying machine.
So, if anyone loses from digital signature pads, it's the merchant.
If the unauthorized charges are due to my own negligence (I lose the card, or the card is stolen and I do not report it in a timely manner), then maybe I'm liable for $50. But as long as I make a reasonable effort to maintain the security of my card and account information, I'm liable for $0.
lost/stolen cards are usually reported by the owner as soon as it is noticed. even so, the credit card companies will remove bogus charges, usually in one phone call. i should know, i worked in a retail furniture store for nearly 4 years. customers, who were legit, but had a case of "buyer's remorse" could call their cc company and get the charges canceled, even though we had 2 sig's; one for the furniture (with a can't cancel clause after 3 days - CT law) and the other on the cc receipt. it doesn't matter, the cc companies all take the old view of AMEX, screw the business, we want to keep our customer.
My guess is that they are just trying to avoid paper records. They probably want/need a signature on file to cover their ass, but they don't actually want thousands of small slips of paper. If I had to deal with auditing reciepts I'd probably kill to have it all digitized.
This is completely wrong. Those pads don't record an image of your signature, they recorde the movements you make with the pen when signing.
I'll assume you're correct, but still, how does this facilitate fraud?
This way, algorithms checking the validity of a signature will detect counterfeits, because even someone who learned to produce a signature which looks exatly the same visually can't reproduce the original.
I don't buy that these devices check any such algorithms. I'd like you to back that one up.
An exact (digital) copy of a previously stored signature would also fail the test.
How so? If you store the motions, rather than the signature, it seems that a replay attack would work perfectly well.
In other words, while a single line of what I said may have been technically incorrect, what are you getting at? My main thesis (that using these devices does not facilitate fraud any more than a regular pen and paper signature) seems to still hold up.
All it takes is a merchant account, your name, number, and expiration date to make charges to your card. (Some cards get you slightly better rates if you provide an actual address and zip code.) The signature doesn't do anything except give them some leverage in case you reject the charges; a dozen transactions with the same signature "proof" is not going to be any leverage worth speaking of!
Being a typical paranoid Slashdotter
sheesh... you make it sound like slashdot readers are as bad as the elderly who sit reading weekly world news and national enquierer and believing all of it...
The leel of detail stored is such that you will never, ever sign a digital pad exactly the same way twice. It isn't possible to do by hand.
Your signature is never even identical. On the other hand, a signature which looks identical but was entered substantially different could be challenege in the future and you would probably not get stuck with the charge. Even if it looked identical to your signature.
My problem with this, is the credit card companies should be given a copy of the digital signature, the vendor should not retain it. Why? Because only the credit card company can verify it isn't a duplicate...
There are other problems with digital signatures, but thats for another day..
Definitly not illegal hear, it is actually encouraged to prevent fraud.
A photocopied license cannot be used for identification purposes, so they can't use it to apply for any services, etc.
I buy gas with my credit card all the time. Never have to sign anything. Never have to enter a pin either.
And these guys are paranoid about signing digitally?
Actually, they record your signature for their protection, and put it in a database that record what you bought when you used your credit card. They do this because if you dispute the charges, the Credit Card company always falls on the side of their customer, unless they have a great reason why they should not believe them. So the first thing the credit card company is going to ask for is proof that the customer made the purchase they claim they did not make. If the merchant can provide the signature, credit card number, and an invoice of what they bought, they are half way towards winning their side of the dispute.
All that the signature pad does is give them a digital carbon copy that they can more easily manage. No more paper receits, and it is easier to keep them all in one centralized repository that they can access if a dispute arrises.
However, this does not mean that you or the merchant can be lax in their duties. You must still watch out for the fraudulent merchant who may charge you for more than the purchase is worth. The waiter who will slip extra items on your bill. We may not have to worry if merchants shred their carbons anymore, but worry about how those who have access to the new storage medium use that access. Always review your credit card statement, and compare it with receits you saved from your purchases. Double check everyone's work, because it is your money they are playing around with.
I haven't lost my mind!
It is backed up on disk...somewhere...
- Slide the paper receipt in, sign, take it out.
- Sign directly on a touchscreen LCD that requires no paper receipt.
The grocery store I mainly visit uses the latter of the two. While I sign the pad it replicates my signature as if it were a pen-touch screen drawing program. Greater then 75% of the time, the machine is b0rk3d and my signature looks like a 50's vector graphics version of the real thing. Seeing this happen so frequently I only assume that what they're capturing cannot be an exact signature (or perhaps the display is just screwing up). I'd say there is a chance that what they're capturing is actually a signature pattern.shrug
I'm against picketing, but I don't know how to show it.
At first I thought you were just paranoid. As a credit card user you are protected against fraud in many ways. Plus the card company goes pays a lot of money for systems that statistically search for fraud. I know because a friend works for the company that provides the software to most of the banks that issue cards use. Plus, after all it's not any harder to steal your signature the old fashioned way - with a scanner.
I actually ran into this issue at work once. My boss wanted his signature scanned so that he could have it on his letterhead and never have to pull out his pen again. That is until I asked him how secure he thought his computer was. Yes, security was my responsibility but they didn't give me much time to spend on it and virtually no budget. Plus I think his password was "porsche" and he wasn't about to change it.
Anyway that was 10 years ago. It does bring up the reason to be paranoid, however. A database of signatures is a worthy target for any cracker and it's likely worth something to the holding company. So what do they do with it anyway? I can't imagine that the benefits of being able to produce the signature from anywhere is all that great. Plus you can't prove that the signature didn't come from a different purchase or a different databse anyway. So why go through all this trouble? I would be interested to hear the stats on the fraud that this kind of system prevents. I'm guessing it's minimal. So what is the worst case here? Likely nothing but then again a cracker could use the data for purchases or identity theft and a malicious company could use the database for something like spam only much worse. "He said we could handle his long distance. See, we even have his signature"
BTW, I like the earlier post about dragging your fingernail across the paper. Yea, some systems might require extra passes of the pen but it's simple and effective.
My problem with this, is the credit card companies should be given a copy of the digital signature, the vendor should not retain it. Why? Because only the credit card company can verify it isn't a duplicate...
The signature isn't for verification, it's for non-repudiation. Since the person who has to lose from repudiation is the merchant, that's who should keep the signature.
Its unfortunate that companies are deciding they need us to prove ourselves to them, but they don't take basic security into account for us. More and more people who have no right to are demanding my social security number, signature electronically or thumbprint. And I refuse.
First off its illegal to demand a SSN unless they are your employer, bank, stock broker or the army and you're enlisted. Every credit card that demands it is breaking the law.
The solution to that is to give them a bogus one-- unless you're applying for credit. Then if you give them a bogus one its fraud, even though its illegal for them to ask in teh first place-- unless you give them a patently bogus one.
Anyway, I have learned that the idiots that work for these companies don't understand security and think you're being stubborn for protecting your rights, so I stopped arguing with them-- I just blow them off. The UPS guy asks me to sign for packages and I do-- but the signature bears no relation to my name.
Same thing when asked to electronically sign for a credit card- I give them a bunch of squiggles... so far nobodies actually compared.
Thumbprints are the worst-- bank tellers are the most obnoxious about saying its for my protection-- which is the most blatant lie I've ever heard. They don't take to well to being asked "Exactly how does this protect me?" Usually I refuse. So far they haven't escalated the issue-- I think they sense the eagerness with which I approach the opportunity to dress down a bank manager on how lax their security is, and how ironic it is that a BANK has such bad security, in front of all their customers. The thing is - these people KNOW that they are not providing adequate security, but they don't have the power to change it either.
It is your duty, whenever someone demands of you something that is not their right to demand, to give them a bogus biometric. Its the only way to protest and its the only way to protect yourself.
So far, writing to companies and pointing out that using SSN as a "password" is stupid (every bank I know of does this) has gotten nowhere. But office Depot, UPS, et al, have a lot of useless signatures on file.
Yeah, and you guys panned the ipod too: http://apple.slashdot.org/article.pl?sid=01/10/23
I suspect that they're also required to collect SSNs for regular checking accounts. It helps the Fed catch those nasty money-laundering drug-dealing kid-porno-peddling terrorists. :-)
Of course. Which actually is really just yet another reason the IRS is a bad idea. That they use it for passwords however is unacceptable.
This is yet another reason we should get rid of the current system and implement a Fair TAx: www.fairtax.org
Yeah, and you guys panned the ipod too: http://apple.slashdot.org/article.pl?sid=01/10/23
Fry's opperates in several states (at least three), however as their largest presence is in california, I'll assume you're there.
I know california has a _lot_ of privacy laws, and their laws are online. I seem to recall hearing about one that prevents merchants from writing your license number on checks you write to them, if you request they do not, or something.
Need a Catering Connection
You know, Mastercard, Amex, Visa, and Discover all tell you to sign your card as soon as you receive it. As an example, here's Mastercard's Fraud Info page.
I'm not going to do your research for you but I've seen statement mailers, various web pages, and other consumer info from each of them over the years that all said "See ID" or similar is not valid to put on the card. More importantly, unless that card is signed with your signature rather than some bogus phrase, you technically haven't followed your terms of the contract. Arguably they could claim that because you didn't sign the card, they aren't liable, because you didn't take the reasonable (and required under the contract) action of signing the card.
"See ID" is a nice idea, but it's kind of like that wacky MS EULA-bypass stuff we always see here. People get some idea that by finding a way not to take a specific physical action like clicking a button or signing a card, they've changed the contract. I doubt that would hold up. There may even be unintended consequences like claiming the cardholder didn't take the necessary and reasonable steps to protect the card.
(And in the case of the EULA-bypasser, MS might claim use of a "circumvention device" under the DMCA.)
Yep, where I used to work, the delivery guy would turn up with sometimes hundreds of pounds' worth of IT kit, and expect us to sign something saying it had been received in good condition/working order/etc. without even opening the (frequently badly dented) cardboard packaging. And of course, the signature was digital, so how that's supposed to be bound to any meaningful statement about what condition things were in is beyond me.
Standard unofficial office policy involved signing yourself Mickey Mouse, or X|ZYY or some such. No-one ever noticed or complained.
If you disagree, post your argument. (-1, Overrated) isn't your personal censorship tool for views you don't like.
I have worked in the field of Biometrics, and this statement is just not true. In many implementations of signature pads, the pressure is also measured (and even displays thicker lines because of it). Most signature recognition algorithms also use the varying pressure as a factor in the matching algorithm.
A traced signature will _not_ match on any matching software I used.
T
---- It puts the lotion on its skin or else it gets the hose again. It does this whenever it's told.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.