13-04-2017, 12:18 PM
A graphical password is an authentication system that works by selecting the user of the images, in a specific order, presented in a graphical user interface (GUI). For this reason, the graphical password approach is sometimes referred to as GUA. A graphical password is easier than a text-based password for most people to remember. Suppose an 8-character password is required to enter a particular computer network. Instead of w8KiJ72c, for example, a user can select images of the earth (between a screen full of real and fictitious planets), the country of France (from a world map), the city of Nice (from a map of France ), A white stucco house with arched doors and red tiles on the roof, a green plastic refrigerator with a white lid, a packet of Gouda cheese, a bottle of grape juice and a cup of pink paper with little green stars around From its upper edge and three red bands around the center.
Graphical passwords can offer better security than text-based passwords, since many people, in an attempt to memorize text-based passwords, use clear words (rather than the recommended mixture of characters). A dictionary search can often hit a password and allow a hacker to enter a system in a matter of seconds. But if a series of selectable images is used on successive screen pages, and if there are many images on each page, a hacker should test all possible combinations at random. If there are 100 images in each of the 8 pages in an 8-image password, there are 1008, or 10 quadrillion (10,000,000,000,000,000) possible combinations that could form the graphic password! If the system has a built-in delay of only 0.1 seconds after selecting each image until the next page is displayed, it would take (on average) millions of years to enter the system by hitting it with random image sequences.