tag:blogger.com,1999:blog-5250637565410657060.post5382441517560849847..comments2015-08-19T07:37:55.060-07:00Comments on LumberBlog: Credit card numbers and Benford's LawMike Mettlerhttp://www.blogger.com/profile/07247095278969509051noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5250637565410657060.post-90058517215426814562011-10-26T06:10:21.436-07:002011-10-26T06:10:21.436-07:00Hi there Mike, I understand why this chart has to ...Hi there Mike, I understand why this chart has to be posted. But anyway, should it be possible that due to lack of number uniqueness, I should be asked to file for <a href="http://aaacreditguide.com/credit-repair-letters/" rel="nofollow">credit repair letters</a> ?Markyhttps://www.blogger.com/profile/04985906534175675896noreply@blogger.comtag:blogger.com,1999:blog-5250637565410657060.post-54281439635321062542011-10-17T23:29:41.932-07:002011-10-17T23:29:41.932-07:00Hello! Thank you for sharing those relative inform...Hello! Thank you for sharing those relative information between credit cards and Benford's Law.<br /><br /><br /><a href="http://aaacreditguide.com/credit-repair-letters/" rel="nofollow">credit repair letters</a>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5250637565410657060.post-20309356766462320692011-06-23T09:53:43.754-07:002011-06-23T09:53:43.754-07:00HI Mike,
First off great product! And great Prod...HI Mike,<br /><br />First off great product! And great Product announcement! Congratulations.<br /><br />Great insights can be had using Bedford's Law! The results of your study is fascinating. I believe that you are seeing the results of the way Payment Card Numbers are encoded. They use a process of Luhn Formula or the Modulus 10 algorithm. <br /><br />The formula verifies a number against its included check digit, which is usually appended to a partial account number to generate the full account number. This account number must pass the following test:<br />Counting from the check digit, which is the rightmost, and moving left, double the value of every second digit.<br /><br />Sum the digits of the products (eg, 10 = 1 + 0 = 1, 14 = 1 + 4 = 5) together with the undoubled digits from the original number.<br /><br />If the total modulo 10 is equal to 0 (if the total ends in zero) then the number is valid according to the Luhn formula; else it is not valid.<br /><br />Assume an example of an account number "4992739871" that will have a check digit added, making it of the form 4992739871x:<br /><br />Account number 4 9 9 2 7 3 9 8 7 1 x<br />Double every other 4 18 9 4 7 6 9 16 7 2 x<br />Sum together all numbers 64 + x<br /><br />To make the sum divisible by 10, we set the check digit (x) to 6, making the full account number 49927398716.<br /><br />And thus there is a non uniform distribution of numbers with a bais to 0 and 1.<br /><br />Hope this helps!<br /><br />∞Brian<br /><br />http://www.quora.com/Brian-Roemmele<br /><br />The account number 49927398716 can be validated as follows:<br />Double every second digit, from the rightmost: (1×2) = 2, (8×2) = 16, (3×2) = 6, (2×2) = 4, (9×2) = 18<br /><br /><br />Sum all the individual digits (digits in parentheses are the products from Step 1): 6 + (2) + 7 + (1+6) + 9 + (6) + 7 + (4) + 9 + (1+8) + 4 = 70<br />Take the sum modulo 10: 70 mod 10 = 0; the account number is probably valid.Brian Roemmelehttps://www.blogger.com/profile/17959283075914699823noreply@blogger.com