Graduate School of Informatics /Cyber Security

In partial fulfillment of the requirements for the degree of Master of Science Rauf Kaan Denizer will defend his thesis.

Title: AN INVESTIGATION OF GRAMMATICAL PATTERNS IN USER PASSWORDS: A PROBABILISTIC CONTEXT-FREE GRAMMAR APPROACH

Date: 03th Sptember 2018

Time: 13:00 PM

Place: A-108

Thesis Abstract : Websites and applications mostly implement authentication methods that employ an account name and a password. According to a recent survey, an e-mail address is associated with 130 different user accounts on average in the US. The high number of user accounts and passwords enforces users to create weak or easily guessable passwords with common patterns such as adding numbers at the end of a password. Developing more complex and costly protective techniques for a password motive attackers to develop methods that are able to guess passwords rather than brute forcing them. Recently studies mostly involve the analyses from users with English as their native language. On the other hand, users who speak different languages may exhibit different patterns while creating passwords. This thesis focuses on grammatical patterns in passwords created by users with Turkish as the native language. We present the findings as well as a framework for probabilistic context-free grammar and its evaluation.