In 1970, the IBM Corporation developed a concept known as the ‘three pillars of identification’. The concept was based on three variables: what you have, what you know and what you are. According to IBM, people could identify themselves to computers or other people by using (i) physical objects, such as documents, keys or cards (ii) shared secrets, such as passwords or personal identification numbers (PINs) or (iii) some distinguishing biological characteristic, such as a fingerprint or the shape of a hand. Some 15 years later, Ben Miller suggested that these three approaches could be used together, in any combination of two or even three pillars. Doing so would improve the trustworthiness of the identification system, allowing people to carry PIN-activated cards, use password-enabled biometrics, store biometric data alongside other card-based ID information, or carry a document with embedded biometrics and passwords. As James Wayman explains, biometrics has come a long way over the past three decades.