Image Based Password Composition Using Inverse Document Frequency

Abstract

Password remains one of the main authentication methods in today’s time. The challenge with password as authentication system is due to its dependency on humans. Its strength and weakness is decided by the alphanumeric string set by users. A number of the websites demand users to use strong passwords even though they do not safeguard any critical information assets. This results in an unnecessary cognitive burden on users. It can be reduced by minimizing the number of strong passwords that he/she has to remember. A password composition scheme that considers criticality of information asset is required for this purpose. This article presents one such scheme using inverse document frequency. Users are authenticated based on a valid English sentence. Sentences leave alphanumeric strings behind in recall due to their semantic nature. Users select their authentication sentence by using an image as context. Humans are good at recalling context based information.