Outline• Introduction• Graphical Passwords• Advantages of Graphical Passwords• Drawbacks• Solution To Shoulder Surfing Problem• Usability• Conclusion
INTRODUCTION• Mostcommon computer authentication method (Text-based passwords). • Difficulty of remembering passwords • easy to remember -> easy to guess • hard to guess -> hard to remember • Users tend to write passwords down or use the same passwords for different accounts• An alternative: Graphical Passwords • Psychological studies: Human can remember pictures better than text
GRAPHICAL PASSWORDS• An authentication system that works by having the user select from images, in a specific order, presented in a graphical user interface (GUI).• The graphical-password approach is sometimes called graphical user authentication (GUA).
CLASSIFICATION TECHNIQUES• Recognition Based Techniques • a user is presented with a set of images and the user passes the authentication by recognizing and identifying the images he selected during the registration stage• Recall Based Techniques • A user is asked to reproduce something that he created or selected earlier during the registration stage
RECOGNITION BASED TECHNIQUESDhamija and Perrig Scheme Sobrado and Birget Scheme• Pick several pictures out of many • System display a number of pass-objects choices, identify them later in (pre-selected by user) among many other authentication. objects, user click inside the convex hull• Take longer to create graphical bounded by pass-objects. passwords
RECOGNITION BASED TECHNIQUES• Other Schemes Using human faces as password Select a sequence of images as password
Recall Based Techniques• Draw-A-Secret (DAS) SchemeUser draws a simple picture on a 2D grid, the coordinates of the grids occupied by the picture are stored in the order of drawing• redrawing has to touch thesame grids in the samesequence in authentication
ADVATAGES OF GRAPHICAL PASSWORDS• Provide a way of making more human-friendly passwords while increasing the level of security.• On average - millions of years to break into the system.• Dictionary attacks are infeasible.
DRAWBACKS• THE SHOULDER SURFING PROBLEM • As the name implies, shoulder surfing is watching over peoples shoulders as they process information. • Examples include observing the keyboard as a person types his or her password, enters a PIN number, or views personal information. • Because of their graphic nature, nearly all graphical password schemes are quite vulnerable to shoulder surfing. Most of the existing schemes simply circumvent the problem by stating that graphical passwords should only be used with handheld devices or workstations set up in such a way that only one person can see the screen at the time of login.• However, it is possible to create schemes to counter shoulder surfing problem
USABILITY• Pictures are easier to remember than text strings• Password registration and log-in process take too long• Require much more storage space than text based passwords
CONCLUSION• Main Argument for Graphical Passwords: • Satisfies both conflicting requirements i.e. it is easy to remember & it is hard to guess.• More difficult to break graphical passwords from traditional attack methods: • Brute Force Search • Dictionary Attack • Or Spyware.• Not yet widely used, current graphical password techniques are still immature.• By implementing other special geometric configurations like triangle & movable frame, one can achieve more security.