MobileMe Scam
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From: nospam on 17 Jun 2010 07:14 In article <michelle-FF7ED1.21474116062010(a)62-183-169-81.bb.dnainternet.fi>, Michelle Steiner <michelle(a)michelle.org> wrote: > > it's true, but there is an additional 3 digit cvv code on the back of > > the card so even if you can hack the number on the front, you still have > > some additional work to do. > > 4 digits on the front for AMEX. Plus many machines (including gas pumps > and at the Apple Stores) require your ZIP code for AMEX cards. i've seen amex cards with a 3 digit code on the back in addition to the 4 digit code on the front, and gas pumps ask for zip code for all credit card transactions, not just amex.
From: David Empson on 17 Jun 2010 08:17 nospam <nospam(a)nospam.invalid> wrote: > In article <1jk8mgp.52bbmo1d2hhuzN%dempson(a)actrix.gen.nz>, David Empson > <dempson(a)actrix.gen.nz> wrote: > > > > the first digit is the credit card type (5=mastercard, 4=visa) and the > > > first six digits identify the bank. > > > > This database is checking for many different combinations of the first > > four digits. It identifies anything starting with 4 as Visa, 5 with > > certain values of the second digit as Mastercard, and a whole bunch of > > other card types which I haven't looked into in detail. > > > > It doesn't go as far as identifying the bank. > > yes it does. I was talking about what this database (Card Validator) was doing, not what the number actually means. The database has a list of card types and how they map to the initial digits (possibly incomplete), but it doesn't have a list of card issuers. > <http://en.wikipedia.org/wiki/Bank_card_number> > > The first 6 digits of the credit card number are known as the Issuer > Identification Number (IIN). These identify the institution that > issued the card to the card holder. The rest of the number is > allocated by the issuer. -- David Empson dempson(a)actrix.gen.nz
From: Wes Groleau on 17 Jun 2010 08:55 On 06-17-2010 08:50, Michelle Steiner wrote: > And I've never had a gas pump ask for my ZIP code when I've used a VISA or > Mastercard. My experience is that around ten percent do. -- Wes Groleau A parent's encounter with his daughter taking Latin http://Ideas.Lang-Learn.us/barrett?itemid=1434
From: Johan W. Elzenga on 17 Jun 2010 09:43 Michelle Steiner <michelle(a)michelle.org> wrote: > In article <170620100714487992%nospam(a)nospam.invalid>, > nospam <nospam(a)nospam.invalid> wrote: > >>> 4 digits on the front for AMEX. Plus many machines (including gas > > > pumps >>> and at the Apple Stores) require your ZIP code for AMEX cards. >> >> i've seen amex cards with a 3 digit code on the back in addition to > > the >> 4 digit code on the front, and gas pumps ask for zip code for all >> credit card transactions, not just amex. > > Yes, there are those three digits on the back of AMEX cards, but I've > never > had anyone check those; they all check the four on the front. > > And I've never had a gas pump ask for my ZIP code when I've used a > VISA or Mastercard. I have when I was in the USA and that's a pain because we use a different code system in my country, that is not recognised by the gaspump. It means I have to go inside first to get my card accepted. It differs from state to state, though. -- Johan W. Elzenga, Editor/Photographer, www.johanfoto.com
From: Thomas R. Kettler on 17 Jun 2010 09:52
In article <1jk8mgp.52bbmo1d2hhuzN%dempson(a)actrix.gen.nz>, dempson(a)actrix.gen.nz (David Empson) wrote: > nospam <nospam(a)nospam.invalid> wrote: > > > In article <1jk8aq9.nyxhig1rnt12tN%dempson(a)actrix.gen.nz>, David Empson > > <dempson(a)actrix.gen.nz> wrote: > > > > > I have a FileMaker Pro database which includes the formula for verifying > > > that a credit card number is valid. It isn't particularly long but it is > > > complex enough that I haven't tried to analyse it. > > > > it's actually very simple. > > I expect so. I meant that it is complex due to being a FileMaker > forumula which is doing a lot of text processing, conversion to numbers, > calculations, nested IF statements, etc., which makes it hard to read. Nearly all credit cards use the Luhn algorithm which is the following: <http://en.wikipedia.org/wiki/Luhn_algorithm> I believe the validation codes have to follow it also, but separately from the credit card number. -- Remove blown from email address to reply. |