[kranthi kumar]

Dear all, Today I would like to share about luhn algorithm also known as Module 10 which is useful in identifying fake sales/transactions reported or mentioned as made by credit card, debit card It is a simple checksum formula used to validate variety of Identification numbers such as credit card, debit card, IMIE numbers I request all of u type your credit card number firstly with valid number and secondly with invalid number in the attached sheet. I am here by attaching the excel sheet with in built formula, anybody who is interested to know the formulas can unhide the sheet. Best Regards, CA Kranthikumar kedari MCOM, FCA, DISA(ICAI) Partner, MANOHAR&VENKATA CHARTERED ACCOUNTANTS Cell:9493264564 Land line: 040-267612101

[sheik nazeer]

Dear Kranthi

                  Thankyou kranthi, can you explain me the logic behind the calculations in the hidden columns in the excell sheet.

Regards 

Nazeer

[kranthi kumar]

Dear nazeer, the logic is as follows  out of 16 digits 15 digits are relating to  the Account number and last one digit is check sum this check sum however is not a criptographic hash function it is a simple check sum used to validate whether the number is entered correctly. all the credit card/Debir card uses the luhn algorithm as check sum like ISBN check sum for ISBN however ISBN check sum is used to identify more than single digit error where as luhn algorithm is used for singll digit error the logic is to double all the 15 digits in alternate i.e  double all odd digits and sum up the odd digits doubled value(in case if get 2 digits sum the two digits i.e 13 will become 1+3=4) with even digits and devide by 10 if there is no remainder thin the number is valid else invalid

Best Regards, CA Kranthikumar kedari MCOM, FCA, DISA(ICAI) Partner, MANOHAR&VENKATA CHARTERED ACCOUNTANTS Cell:9493264564 Land line: 040-267612101

--- On Sun, 1/27/13, sheik nazeer <nazee...@gmail.com> wrote: