From ACT Wiki
Two-factor authentication is a principle of security systems requiring additional features on top of standard usernames and passwords.
The additional features may be something you:
- Know: for example, a personal identification number (PIN), an additional password, answers to “secret questions” or specific keystroke patterns
- Have: for example a credit or debit card, a smartphone, or a small hardware token
- Are: for example, a fingerprint, iris scan, or voice print
- Keep control
- "... the importance of not relinquishing your own control requirements, as a number of companies that turned off two-factor authentication when they went live with a cloud solution were subsequently breached."
- Ludwig Keyser, Director of Joint Operations Centre, Barclays - EACT Conference Tackling cyber risks in treasury, January 2019.