Hill’s code is one of text encoding technique. In this research, Hill’s code is
extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used
as a key. The results show that Hill’s code is suitable for image whose RGB values vary highly. On
the contrary, it is not suitable for less varied RGB images since its original pattern is still
persisted in encrypted image.
Hill’s code for image encoding has also disadvantage in the case that the key matrix is not
unique. However, for daily application, with good key matrix, Hill’s code can be applied to encode
image since it’s process only deals with simple matrix operation so it become fast.