Two factor authentication

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The use of two-factor authentication to prove one's identity is based on the approach that both the required factors must be used and must be correct. If one of the components is missing or is used incorrectly, a person's identity cannot be established beyond doubt. Access to the building, access to data or access to whatever is being protected by two-factor authentication remains blocked if this is the case. The factors may include:

  • something that the user possesses, such as a USB stick token, a bank card, a key etc.,
  • something that the user knows, such as a username, password, PIN, TAN etc., and
  • something that the user is and is inseparable from, a physical characteristic of the user, such as a fingerprint, eye iris, voice, etc.

Tokenless two-factor authentication[edit]

The major drawback of authentication performed using something that the user possesses and one other factor is that the plastic token used (the USB stick, the bank card, the key or similar) must be carried around by the user at all times. And if this is stolen or lost, or if the user simply does not have it with him or her, access is impossible. In addition, there are costs involved in procuring and subsequently replacing tokens of this kind.


Advantages of tokenless two-factor authentication:

  • The option to specify a maximum permitted number of false entries reduces the risk of attacks by unauthorised persons

See also[edit]

External links[edit]