16-Digit Credit Card Numbers
Open Source and Standards Accomplishment | 1954
IBM researcher: Hans-Peter Luhn
Where the work was done: IBM T.J. Watson Research Center
What we accomplished: The worldwide standard for 16-digit credit card numbers and the basis of ISO/TEC 7812-1 (Hans-Peter Luhn, pictured).
Related links: Hans-Peter Luhn (ASIS&T)
Image credit: ASIS&T