Talk:Card security code: Difference between revisions

Revision as of 17:47, 5 August 2010

Revision as of 11:23, 12 October 2010

Line 1:

{{WikiProject Business & Economics|class=start|importance=mid}}

{{WikiProject Numismatics}}

{{Exonumianotice}}

==Related to actual number?==

Q. Is the CVV2 number related to the actual credit card number? Is it a random number? Or is there some other way that the card issuer selects the CVV2 number to put on a card?

<small><span class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:207.233.79.134|207.233.79.134]] ([[User talk:207.233.79.134|talk]] • [[Special:Contributions/207.233.79.134|contribs]]) 23:27, 4 August 2005</span></small><!-- Template:Unsigned -->

{{unsigned|207.233.79.134| 23:27, 4 August 2005}}

A. I don't think MC or Visa require a particular algorithm, so it can be a random number stored in a secure lookup table, or it can be a derived number based on card data using a secret issuer key.

<small><span class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:38.112.4.254|38.112.4.254]] ([[User talk:38.112.4.254|talk]] • [[Special:Contributions/38.112.4.254|contribs]]) 21:02, 31 March 2006 </span></small><!-- Template:Unsigned -->

{{unsigned|38.112.4.254| 21:02, 31 March 2006 }}

:: The CVV2 is an encryption of the card number and expiry date, under a key known only to the issuing bank. The CVV on the magstripe is similar but the encryption also covers the service code, a value on the magnetic stripe. [[User:Zaian|Zaian]] 10:46, 18 June 2006 (UTC)

Line 38:

This is a guess, but it seems reasonable.

<small><span class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:82.93.59.73|82.93.59.73]] ([[User talk:82.93.59.73|talk]] • [[Special:Contributions/82.93.59.73|contribs]]) 18:18, 21 August 2005</span></small><!-- Template:Unsigned -->

{{unsigned|82.93.59.73| 18:18, 21 August 2005}}

:Well, it is not so dificcult for an employer of a shop (or for the owner of the shop too) to look at the secutity code without being seen as suspicious. On some cards the security code is on the front and in other cases is next to the signaure box on the back of the card (which the merchant has contract right and duty to check at). The code is enought small to be memorized, so there no need to write it down immidiately rising suspicious. Morover in many case I see the teller write down on the credit card recipes many informations (the number of the day selling, and so on). The security code could be written among the same datas without rising souspicious, or it can even be written in a encripten form. if the fraud is made some time later (even months since the card is usually valid for 2 years and all the information needed, including the security code, do not change in the meantime) it would very difficult to track down all the place it was used in the time. And unless the teller is so silly to buy things online and have them sent to his/her postal address, it is very difficult to link among the use of the credit card and a specific sale, when the card was use.