Heather, a computer forensics investigator, is assisting a group of investigators working on a large computer
fraud case involving over 20 people. These 20 people, working in different offices, allegedly siphoned off
money from many different client accounts. Heather responsibility is to find out how the accused people
communicated between each other. She has searched their email and their computers and has not found any
useful evidence. Heather then finds some possibly useful evidence under the desk of one of the accused.
In an envelope she finds a piece of plastic with numerous holes cut out of it. Heather then finds the same exact
piece of plastic with holes at many of the other accused peoples desks. Heather believes that the 20 people
involved in the case were using a cipher to send secret messages in between each other. What type of cipher
was used by the accused in this case?
A.
Grill cipher
B.
Null cipher
C.
Text semagram
D.
Visual semagram