  The Arnold Cat Map (ACM) is a popular chaotic map used in image encryption.
Chaotic maps are known for their sensitivity to initial conditions and their
ability to mix, or rearrange, pixels. However, ACM is periodic, and the period
is relatively short. This periodicity decreases the effective key space for a
cryptosystem. Further, ACM can only be performed on square matrices. For
non-square images, this issue can be solved by performing ACM on multiple
square partitions of the image. If these partitions overlap, the periodicity
will greatly increase. The resulting system will be referred to as overlapping
ACM or OACM. This paper will cover the implementation and periodicity analysis
for these overlapping systems, which previous papers involving similar
overlapping block partitions did not. Viewing OACM as a scan as opposed to a
map allows for faster implementation and period analysis.
