Introduction - Cryptology Unlocked - page 1

Chapter 1
Introduction
We live in a world where information and its exchange play central roles, and
yet it's only the beginning of the information age. It will become increasingly
important to protect information which, in turn, requires knowledge in cryptol-
ogy. Cryptology encompasses two fields: cryptography , which is, roughly
speaking, the science of data protection by encryption, and cryptanalysis ,
which is the art of obtaining information on secret data without knowing the
key. Though people have been dealing with cryptology for several thousands
of years, it is still somewhat mystery-mongered. It is also a difficult field. First,
every cryptologist needs to have sound mathematical knowledge. Second, a
cryptologist is often hindered by the fact that he's either bound to confiden-
tiality, or that research findings are kept secret. Cryptology still hasn't rid
itself of its reputation of being a playground for national intelligence agencies,
diplomats, and militaries, though it has meanwhile made its way into every-
day use — think only of your bank card's PIN, or digital cell phones. On the
other hand, for example in the United States up into the 1990s, good (secure)
encryption algorithms had been banned from export. They were classified as
'ammunition'. In France, cryptography was thought of as the second most dan-
gerous type of weapon, and its use had to be approved by the Prime Minister
(explicitly excluding criminals and alcoholics). Meanwhile, the regulations have
loosened up in France, too.
Knowledge of good cryptographic methods and mainly their correct use is
still not widely disseminated. We often use bad or unpublished algorithms, or