PIN Length
The concept of a PIN originates with the inventor of the ATM, John Shepherd-Barron. One day in 1967, while thinking about more efficient ways banks could dispense cash to their customers, it occurred to him that the vending machine model was a proven fit. For authentication Shepherd-Barron at first envisioned a six-digit numeric code, given what he could reliably remember. His wife however preferred four digits, which became the most commonly used length. ISO 9564-1, the international standard for PIN management and security, allows for PINs from four up to twelve digits, but also notes that "For usability reasons, an assigned numeric PIN should not exceed six digits in length."
Apart from financial uses, GSM mobile phones specify a PIN of between four and eight digits. The PIN is recorded in the SIM card.
Read more about this topic: Personal Identification Number
Famous quotes containing the words pin and/or length:
“What pursuit is more elegant than that of collecting the ignominies of our nature and transfixing them for show, each on the bright pin of a polished phrase?”
—Logan Pearsall Smith (1865–1946)
“Punishment followed on a grand scale. For ten days, an unconscionable length of time, my father blessed the palms of his child’s outstretched, four-year-old hands with a sharp switch. Seven strokes a day on each hand; that makes one hundred forty strokes and then some. This put an end to the child’s innocence.”
—Christoph Meckel (20th century)