teller. During a transaction, the customer's account number was read by the card reader. This process replaced manual entry and avoided possible key stroke errors. It allowed users to replace traditional customer verification methods such as signature verification and test questions with a secure PIN system. In recognition of his work on the PIN system of information security management, Atalla has been referred to as the "Father of the PIN". The success of the "Atalla Box" led to the wide adoption of PIN-based hardware security modules. Its PIN verification process was similar to the later IBM 3624. By 1998 an estimated 70% of all ATM transactions in the United States were routed through specialized Atalla hardware modules, and by 2003 the Atalla Box secured 80% of all ATM machines in the world, increasing to 85% as of 2006. Atalla's HSM products protect 250million card transactions every day as of 2013, and still secure the majority of the world's ATM transactions as of 2014. Financial services PIN usage In the context of a financial transaction, usually both a private "PIN code" and public user identifier are required to authenticate a user to the system. In these situations, typically the user is required to provide a non-confidential user identifier or token (the user ID) and a confidential PIN to gain access to the system. Upon receiving the user ID and PIN, the system looks up the PIN based upon the user ID and compares the looked-up PIN with the received PIN. The user is granted access only when the number entered matches the number stored in the system. Hence, despite the name, a PIN does not personally identify the user. The PIN is not printed or embedded on the card but is manually entered by the cardholder during automated teller machine (ATM) and point of sale (POS) transactions (such as those that comply with EMV), and in card not present transactions, such as over the Internet or for phone banking. PIN length The international standard for financial services PIN management, ISO 9564-1, allows for PINs from four up to twelve digits, but recommends that for usability reasons the card issuer not assign a PIN longer than six digits. The inventor of the ATM, John Shepherd-Barron, had at first envisioned a six-digit numeric code, but his wife could only remember four digits, and that has become the most commonly used length in many