Cryptography Reference
In-Depth Information
Chapter 17
Steganalysis
17.1 Code Words
Authors of recommendation letters often add a secret layer of mean-
ing hidden beneath the surface of a letter that is ostensibly positive.
•
All of his colleagues are astounded by his scrupulous attention
to detail
and
the zeal with which he shares this information.
•
Letusjustsaythathisstrengthishisweakness.
•
Bold words and sweeping statements are his friend.
•
We continue to be amazed by his ability to whip off articles,
journal papers, and conference talks with such a minimal time
in the lab.
•
This candidate is a master of the art of not saying what he
means. He slips quickly between two-faced disinformation and
carefully worded calumny.
17.2 Finding Hidden Messages
Many of the techniques in this topic are far from perfect. A wise at-
tacker can identify files with hidden information by looking carefully
for some slight artifacts created by the process of hiding information.
In some cases, the tests are easy enough to be automated with a high
degree of reliability. This field is often called
steganalysis
, a term that
mimics the word
cryptanalysis
,thestudyofbreakingcodes.
