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  1. #1
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    Default Credit Card Problem Thats NEVER happened.

    Hello. In ten years, and thousands of orders using OSC and ZEN, this has never happened.

    A customer placed an order using his Visa number. The customer only entered 15 digits and NOT the required 16. He was still allowed to checkout, and of course, I only received the middle 7 digits instead of 8.

    I logged into the site as a customer and attempted to place an order using the Visa test number. I only entered 15 digits and got the error code that I didn't use enough numbers. I then attempted the (15) numbers the customer gave me and sure enough, the cart let me checkout.

    Any suggestions/advice on how to prevent this from happening in the future would be appreciated.

    Thanks,
    Tom

    1.38 and only minor mods. Site has been running flawlessly for 6 months and hundreds of orders. Of the 7 orders yesterday, this one was the only one that had the above problem.
    NicotineRush dot com Nasal Snuff & Accessories

  2. #2
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    Default Re: Credit Card Problem Thats NEVER happened.

    You are using what payment module?
    Please do not PM for support issues: a private solution doesn't benefit the community.

    Be careful with unsolicited advice via email or PM - Make sure the person you are talking to is a reliable source.

  3. #3
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    Default Re: Credit Card Problem Thats NEVER happened.

    Just the basic cc module that comes with zen.
    NicotineRush dot com Nasal Snuff & Accessories

  4. #4
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    Default Re: Credit Card Problem Thats NEVER happened.

    1. What are the first 8 digits?
    2. What happened when you submitted the 15-digit number on your POS/terminal for processing?
    .

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  5. #5
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    Default Re: Credit Card Problem Thats NEVER happened.

    Quote Originally Posted by DrByte View Post
    1. What are the first 8 digits?
    2. What happened when you submitted the 15-digit number on your POS/terminal for processing?
    4661 8003 (not an amex card)


    Terminal came back with an error code saying I did not have enough digits.
    NicotineRush dot com Nasal Snuff & Accessories

  6. #6
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    Default Re: Credit Card Problem Thats NEVER happened.

    Apply the LUHN algorithm to the 15 digits that you have - see if it verifies...

    (see google for LUHN - or Mod-10 - algorithm... It's quite an easy forumla to test.)

  7. #7
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    Default Re: Credit Card Problem Thats NEVER happened.

    Quote Originally Posted by fairestcape View Post
    Apply the LUHN algorithm to the 15 digits that you have - see if it verifies...

    (see google for LUHN - or Mod-10 - algorithm... It's quite an easy forumla to test.)
    Yes, it verifies.

    update. Customer just got back to me with the missing digit. Was this just a coincidence?
    Tom
    Last edited by bakdoor; 18 Jan 2009 at 05:00 PM.
    NicotineRush dot com Nasal Snuff & Accessories

  8. #8
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    Default Re: Credit Card Problem Thats NEVER happened.

    That is most unusual for a 16-digit card!

    ZC Version 2.0 (and thereafter) will, I believe, NOT include the CC module as standard.

    I know that Conor Kerr (ceon) (dev.ceon.net) developed a C-card module that he says is more secure and robust that the standard ZC offering.

    You may care to take a look, and send a PM to ceon asking him if this unusual event is possible with his module.

  9. #9
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    Default Re: Credit Card Problem Thats NEVER happened.

    Thank you. I will. Am I correct in assuming that the chances of this happening again are very slim?
    Tom
    NicotineRush dot com Nasal Snuff & Accessories

  10. #10
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    Default Re: Credit Card Problem Thats NEVER happened.

    Hi Tom,

    I too have never heard of a card number passing the LUHN check when a digit has been dropped off. Obviously the fact that it has happened means that, while being statistically unlikely, it is indeed possible for a LUHN check to pass an invalid card number as valid.

    There's not much that can be done about that.

    However, I highly recommend that you use a payment gateway which charges cards live, no store should really be using a terminal to charge the cards. If you've had thousands of transactions then you really shouldn't be using this method for charging cards, I'm pretty sure you'd be in serious breach of your merchant account's terms and conditions.

    The Ceon Manual Card module does work better than the standard Zen Cart module but it uses the same LUHN checking algorithm so the same situation would occur with it.

    As is mentioned in the module's documentation, although we wrote and released this module we actually don't recommend that anyone uses it and that stores only use a payment gateway to take customer's money! :)

    If you are going to continue using a terminal though I do recommend installing Ceon Manual Card, it has a nice sidebox to display cards accepted and other such small niceities. ;)

    All the best...

    Conor
    Ceon

 

 

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