Pixel Value Graphical Password Scheme: Fake <i>Passpix</i> Attempt on Hexadecimal Password Style

Abstract

Early design of graphical password scheme solved the strong alphanumeric password deficiencies in term of hard to memorized, but they was exposed to password shoulder surfing and complicated to produced even by the legitimate users. Motivated to solve the problems, pixel value graphical password scheme was developed in 2012 where it require user to load any their desired digital image as their password. The term <i>Passpix</i> is referring to the pixel value that extracted from the loaded image file derived from the words password pixel. Pixel value in the form of RGB color strength could be representing as 3-octets 8-bits color code (0 to 255) or Hexadecimal code (000000 to FFFFFF) produced 16,777,216 combinations. Pixel value graphical password increases the password strength by implementing two-dimensional 8 by 8 grid extraction that increases the password strength to 1,073,741,824 combinations. It would result the password could be long or super long. Currently, pixel value graphical password scheme using the 8-bits color code as the pixel value and password that stored into database which could produce up to 576 characters. This would be require more storage capacity to store the password that brings into a suggestion to extracting the pixel value using hexadecimal code which produced 384 characters only. Further study on that idea it is found that the number of password characters did not brings a significant impact on-disk data size and it is easy information to construct a fake <i>Passpix</i> which is discussed further in this paper. This paper is organized into 5 sections where the background and concept of pixel value graphical password scheme is introduced in section 1. Section 2 of this paper is describing the password style of pixel value graphical password. The fake <i>Passpix</i> reconstruction is briefly explained in section 3 and section 4 is discussed further about the fake <i>Passpix</i> findings. The conclusion of this study can be found in section 5 and at the end of this paper, there are list of several references used in this study. Hopefully this paper will brings major contribution for safer pixel value graphical password scheme.