Draw a Secret

Draw a Secret (DAS) is a graphical password input scheme developed by Ian Jermyn, Alain Mayer, Fabian Monrose, Michael K. Reiter and Aviel D. Rubin and presented in a paper at the 8th USENIX Security Symposium in Augusts 1999.

The scheme replaces alphanumeric password strings, with a picture drawn on a grid. Instead of entering an alphanumeric password, this authentication method allows users to use a set of gestures drawn on a grid to authenticate. The user's drawing is mapped to a grid on which the order of coordinate pairs used to draw the password are recorded in a sequence. New coordinates are inserted to the recorded "password" sequence when the user ends one stroke (the motion of pressing down on the screen or mouse to begin drawing followed by taking the stylus or mouse off to create a line or shape) and begins another on the grid.

Overview

In DAS, a password is a picture drawn free-form on a grid of size N x N. Each grid cell is denoted by two-dimensional discrete coordinates (x, y) ∈ [1, N] × [1, N]. A completed drawing, i.e., a secret, is encoded as the ordered sequence of cells that the user crosses whilst constructing the secret.