Criminals can guess Visa number and security code in six seconds, experts find

Re:Criminals can guess Visa number and security code in six ... by ctrl-j on Sunday December 04, 2016 @02:56PM (#13101470)

> I'd bet that almost all don't have three numbers all the same and that there are probably more rules/conventions that would reduce the search space.

You're correct that almost all don't have three identical digits, but that's just because there's only 10 of them -

000, 111, 222, 333, 444, 555, 666, 777, 888, 999

10/1000 = 1%

I doubt they would make up rules for determining the cvv, as it would only improve security until bad actors could determine the rules - then it would hinder security as there would be less entropy in the selection space.

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Re:Criminals can guess Visa number and security code in six ... by aquadrop on Sunday December 04, 2016 @06:45PM (#13102415)

I think they can be same, but they always > 99 (at least I never saw a card with CVV starting with 0)

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Re:Criminals can guess Visa number and security code in six ... by ctrl-j on Monday December 05, 2016 @12:07AM (#13103495)

A coworker of mine thought the same. Parsed the string into an int - we saw a bunch of cards get declined by our gateway processing company. They definitely can have leading zeroes.

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Re:Criminals can guess Visa number and security code in six ... by girvo on Sunday December 04, 2016 @07:08PM (#13102510)

I have, it was a Visa.

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