CVV numbers

Sat Jun 9 21:42:11 UTC 2012

On Sat, Jun 9, 2012 at 2:25 PM, Jimmy Hess <mysidia at gmail.com> wrote:

> Someone must have something in a database that can easily derive the
> CVV2 number;
>

There is no way to "derive" the CVV2 number.  It is little more than a
random number assigned to the card.

> otherwise there would be no way for it to be verified that the correct
> number has
>

It is verified by comparing it to the known CVV2 number stored by the
credit card company/bank that issued the card.

> I bet there is at least one small retailer out there who takes phone
> orders and gathers CVV2, and at least one  POS software developer out
> there who is unaware of, has ignored, or has
> intentionally/unintentionally disobeyed the rule about never storing
> CVV2 values in a database,

Gathering CVV2 number over the phone is completely valid. It's even valid
to write them down, as long as they are destroyed as soon as the
transaction has been completed. Of course there are people that
disobey/ignore/don't know the rules - no level of security will ever be
perfect in this regards - it's all about making the security better and
reducing the rate of fraud/chargebacks.

> In other words CVV2 is a "weak"  physical "proof" mechanism that only
> works if  all parties involved obey the rules perfectly without error,
>

Correct.  It's a "weak" physical "proof" mechanism that has succeed in
having a very significant reduction in fraudulent transactions/chargebacks
across pretty much the entire industry.  Remind me again what your point
was?

  Scott