Questions tagged [credit-card]

Payment cards. For questions about storing credit card numbers, see also pci-dss. For questions involving the physical object, see also smartcard (if the card has a chip).

229
votes
7answers
36k views

All 0s (zeros) in a bank card's CVC code

My bank card recently expired. I got a new one and this one turned out to be "lucky": its CVC code was 000. For a few months I used it extensively, both online and offline, without any difficulties - ...
181
votes
5answers
57k views

Why are chips safer than magnetic stripes?

After the recent Target hack there has been talk about moving from credit cards with magnetic stripes to cards with a chip. In what ways are chips safer than stripes?
137
votes
5answers
260k views

How does Amazon bill me without the CVC / CVV / CVV2?

The card in question is a VISA, if that's of any importance. I've noticed this only on Amazon. All other sites I've purchased something from, ever, have needed the CVC code for the card. However, I ...
84
votes
3answers
8k views

What information about me do stores get via my credit card?

Lets say I buy something at some (physical) store and pay using a credit card on one of these electronic terminals. What information do the owners of this store get about me (or my credit card) from ...
79
votes
7answers
21k views

How many digits of a Visa card number can vendors disclose on receipts?

I visited a local McDonald's, and I noticed part of my Visa number repeated on the receipt like this: NNNN NN__ ____ NNNN. (So out of a total of 16 digits it breaks down like this: First six digits ...
70
votes
10answers
37k views

Can I scratch off the magnetic strip off a debit card to only allow chip and PIN?

I have been robbed in the past by thieves using my HSBC Debit Card (issued by UAE branch) to purchase mobile phones and accessories by signing for the purchases. While the card has chip & PIN ...
62
votes
2answers
7k views

Why is credit card information not stolen more often?

Nowadays there are a lot of hacked websites with stolen login information. In many cases the website states that no credit card data and/or payment information was stolen. Why is that? What I assume ...
61
votes
3answers
7k views

Merchant sent email to me with all my Credit Card info

Is there some place for a consumer to file a complaint concerning improper use of credit card information? I gave my credit card to a towing company and they sent me a receipt via email with all of ...
60
votes
2answers
39k views

Minimum requirements for storing last 4 digits of credit card number?

We have a merchant website that uses Autorize.net's CIM and AIM. Our users may have multiple credit cards so we'd want to give them opportunity to distinguish between credit cards that they use on ...
59
votes
5answers
66k views

What's the impact of disclosing the front-face of a credit or debit card?

There are quite a few cases where people are called out for disclosing the front-face of a credit or debit card (e.g. this tweet from Brian Krebs or this twitter account). So I was wondering what the ...
56
votes
6answers
7k views

Has a benefit been demonstrated for credit card machines asking for ZIP code?

In the U.S., many credit card machines at places like gas stations have started asking for your ZIP (postal) code to use a credit card ostensibly to help verify that you really are the cardholder, ...
52
votes
4answers
15k views

Detecting skimmers and other ATM traps

This question has been bothering me ever since I first heard of ATM skimmers: Instances of skimming have been reported where the perpetrator has put a device over the card slot* of an ATM (...
51
votes
2answers
12k views

Is this Paypal Github SDK reference really a dangerous site?

I'm working on integrating a payment system with paypal in C#, and I installed the official paypal nuget package. Then I went to the paypal github site. And linked to this below site (SDK Reference). ...
51
votes
10answers
40k views

Can a steel woven wallet prevent RFID scanning of credit card information?

According to the Popular Mechanics article RFID Credit Cards and Theft: Tech Clinic, the fact that many new credit/debit cards have a RFID chip embedded on it, there is a risk (albeit, small according ...
47
votes
8answers
9k views

What prevents web shop owners from misusing credit card data?

I don't own a credit card but read much about fraud with stolen credit cards. Since I don't own one, I don't know how you exactly buy online using your credit card, so please correct me, if I am wrong ...
43
votes
7answers
20k views

Amazon let me place an order without me ever being asked for 3-D secure password

I have set a "3-d secure password" for my debit card, on my bank's website. But when I purchased something in amazon.co.uk, I went through the whole process without ever being asked for that 3D ...
43
votes
7answers
25k views

Hashing a credit card number for use as a fingerprint

What's the best way to hash a credit card number so that it can be used for fingerprinting (i.e. so that comparing two hashes will let you know if the card numbers match or not)? Ideally, I'm looking ...
42
votes
5answers
20k views

How does a website know if a certain creditcard number is wrong instantly

I was renewing my Internet subscription through the online portal of my ISP. What struck me was when I was entering my credit card details, I entered the type of my credit card (MasterCard, Visa, AA, ...
38
votes
6answers
9k views

Which parts of a credit card can I obfuscate and still have it be valid

I was recently the victim of credit card fraud and I suspect it is from a merchant somewhere keeping track of my credit card details. I cancelled the card and received a new one, but I would like to ...
38
votes
4answers
9k views

Convince the company not to store credit card numbers in our webapp

The company I work for needs a system to perform monthly credit card charges to customer accounts. Customers will be able to update their credit card information from an online interface written in ...
33
votes
3answers
10k views

Why don't popular web services mask the CVV?

Most popular web services like PayPal, Google Wallet, and others do not mask CVV numbers, eg: (<input type="password">). As I read, the CVV is a security feature and it seems logical to mask it ...
32
votes
1answer
28k views

Is CVV calculated or merely assigned?

Is the 3-digit (4-digit for those acolytes of standardization, American Express!) CVV/CSV/CVC calculated from card number and expiration date, or is it merely assigned? I know that once when I got a ...
30
votes
4answers
25k views

Hotel reservation. How is this secure with only credit card number and expiry date?

Until today I managed to avoid paying online with my credit card (I'm weird, I know...) but somehow I managed to do it. Today though I had to book a hotel room (on booking.com) that required a ...
30
votes
4answers
7k views

How can a website verify that my phone number belongs to me?

I was signing into a Capital One credit card website that I hadn't used in a long time, and once I entered my user name and password, it requested my mobile phone number for additional verification. ...
28
votes
1answer
7k views

Are credit-card security codes theoretically insecure (if not entirely broken) already?

I was reading the Wikipedia article on Card security codes (CSC, CVD, CVV, CVC, V-code, SPC, CID, CV2, CVN2, CAcronym2, etc) and a certain assertion caught my eye (emphasis mine): The CSC for each ...
26
votes
7answers
13k views

Recourse if debit card was used on a suspicious website

My husband got a pop-up ad on his phone for a fashion website and purchased two pairs of sunglasses using our debit card. The confirmation was emailed to me (marked as spam by gmail), and the site ...
24
votes
4answers
53k views

What is the use of stolen credit card details?

What can a person with stolen credit card details do? Buy porn? Buy tons of server resources to perform an attack? What else? I'm sure that if he buys books, shoes and bicycles or transfer funds to ...
24
votes
2answers
39k views

Specific risks of embedding an HTTPS iframe in an HTTP page

I need help listing the specific risks of embedding an HTTPS iframe that enables credit card checkout inside of an HTTP page. Are there security issues with embedding an HTTPS iframe on an HTTP page? ...
22
votes
5answers
70k views

Is it standard practice to ask a customer to send a photo of their credit card to confirm their identity?

My friend ordered clothes from a clothing site and was asked to send a picture of her credit card. Is it standard practice to ask a customer to send a photo of their credit card to confirm their ...
22
votes
3answers
6k views

Is accepting an invalid credit card number a security issue?

I am testing a website which accepts invalid credit card numbers for reservations. The interesting thing is they do CC validation if the currency is USD, but not for any other currencies. Should I ...
21
votes
5answers
9k views

Apart from losing €40, is there any further risk if someone has my prepaid credit card number and home address? [closed]

My girl was scammed and entered my home address and my credit card number on a fake website (through a Facebook ad). What risks am I additionally incurring, apart from having lost €40 (the money that ...
20
votes
4answers
3k views

Credit card forms on HTTP pages a MITM risk?

The other day, there was a web developer mailing list thread about a fundraiser page. One person noted that the page with the credit card form was HTTP, not HTTPS. In response, one person said that ...
19
votes
2answers
2k views

Store Credit Card Information in Password Manager?

For convenience purposes I manage my passwords with the password manager Bitwarden on my personal computer and smartphone with autofill function (but with asking for the master password or fingerprint ...
19
votes
4answers
4k views

In a “card not present” transaction, is the credit card number, expiry date & CVV considered as a “What you have” or a “What you know”?

Is the credit card number, CVV & expiry date considered to be a secret? If so, then the physical credit card is incidental & the info about the card is something "you know". OTOH, if you don't ...
19
votes
5answers
3k views

NFC contactless payment security

This is really bugging me. Up until recently debit cards with an electronic chip were the most popular electronic form of payment available in Poland (I'd wager that in other European countries as ...
18
votes
4answers
19k views

Is Visa PayWave secure?

Recently (well, a few months or even a year ago), my bank, here in Australia, introduced this PayWave technology to their Visa debit cards. They claim it's secure, but all they talk about is their ...
17
votes
3answers
1k views

What prevents people getting charged over NFC in crowded places?

I don't have an NFC-enabled device and I couldn't find any information about this in Google. What is it that protects me against an attacker with a portable NFC terminal charging payments by just ...
16
votes
2answers
377 views

Is adding a supplementary credit transaction something that could improve online payment security?

An online company from which I regularly buy goods apparently recently upgraded their security policy. Let's say I bought something for 73,31€. As usual this company uses 3D-Secure for the checkout ...
15
votes
4answers
32k views

Is a 3 or 4 digit CVV enough for online transactions?

Background: The CVV/CVV2 number ("Card Verification Value") on a credit card or debit card is a 3 or 4 digit number printed on the card. It is 3 digits on VISA, MasterCard and Discover branded credit ...
15
votes
3answers
21k views

Is storing CVV compliant with PCI standards?

From personal, job-related experience I know that many "Booking Engines" store the CVV info for customers' credit cards from the time a reservation is made until the time the guest leaves the hotel. ...
15
votes
5answers
517 views

I need ideas for blocking a single malevolent user

Let me throw out this problem I'm having to some of my technical peeps and see if you guys have any new suggestions: We have a website that sends text messages and voice mails for our clients. ...
14
votes
4answers
3k views

Collecting credit card info in HTTPS iframe within an HTTP site

slate.com's paid membership program collects credit card info inside an HTTPS iframe over plain HTTP . The HTTPS url is https://my.slate.com/subscriptions/manage/. In an article, they claim this is ...
14
votes
3answers
2k views

Should I worry if my credit card payment processor's server allows only weak SSL cipher suites?

I tested their server using https://www.ssllabs.com/ssltest/ and, apart from the disappointing "B" rating (it handles financial transactions, after all), the server only allows the following two RC4 ...
14
votes
3answers
29k views

Is it safe to auto-fill credit card numbers using Chrome?

Is it safe to auto fill credit card numbers using Chrome? Does it safely store the credit card information? As far as my understanding goes, it just shows asterisk values but on click it reveals the ...
14
votes
1answer
2k views

How safe is my contactless bank card?

In the past few years Contactless Payment cards have been introduced and I have been reading some articles surrounding security of these cards. The following article "Stealing data from contactless ...
13
votes
3answers
18k views

What is the DUKPT Key Derivation Function?

I'm tasked with decrypting ciphertext acquired from an encrypted card reader. The card reader utilizes DUKPT(derived unique key per transaction) scheme and 3DES encryption. I don't have a problem with ...
13
votes
3answers
37k views

Is it possible to clone an RFID/NFC card using a simple RFID reader, for future reuse and impersonation?

RFID/NFC technology is used in credit cards and many other personal identification applications. Is it possible/how easy is it to clone a card using a simple RFID reader? In other words, can the ...
11
votes
2answers
28k views

Safety of publishing last 4 credit card digits in age of fast computing?

How safe is it to make public the last four digits of a credit card? Credit card numbers have a specific format. Digits tell you what type of institution issued the card, what bank issued the card, ...
11
votes
1answer
3k views

Properly masking credit cards

I'm wondering if the following masking of credit card would be considered PCI compliant. ######??????#### # Is plaintext ? is redacted Expiration date is available in plaintext Is it reasonably ...
11
votes
3answers
2k views

Storing Credit Cards

Okay, so storing digitized credit card information/records is a well documented process when it comes to best practices. I recently got asked how a company can store, retrieve and process physical ...