Cryptography Reference
In-Depth Information
stage of this process is deficient then it is likely that the desired security services
are not provided, despite the use of cryptography.
Cryptography is not only for mathematicians
. It is certainly true that most
cryptographic mechanisms rely on mathematical ideas. However, we hope
that we have made the case that understanding what cryptography does, and
how it can be used, does not require extensive mathematical knowledge.
Cryptography must be handled with care
. Bruce Schneier later expressed
some regret that some people treated his book
Applied Cryptography
[168]
as a complete source of cryptographic knowledge. His mistake was that by
popularising and explaining cryptographic principles, he gave some readers
too much confidence that they now knew everything. We hope that we have
provided enough caveats to make it clear that this topic should not be treated
in such a way. This topic is a starting point for a cryptographic adventure, not
a comprehensive guide. We have concentrated on principles at the expense of
detail. In cryptography, unlike certain other subjects, detail is often absolutely
crucial. Cryptography is not a subject for 'do-it-yourself' amateurs, even well-
informed ones. The best advice is to always listen to the experts, consult the
standards, and pursue a policy of safely following the knowledgeable crowd.
Those who stray from this advice by attempting to exhibit cryptographic
flare and creativity are rarely rewarded. Cryptographic standards are normally
painstakingly prepared and scrutinised. It is generally wise to follow them.
Our explanation of the cryptographic toolkit and key management has
focussed on fundamental principles and illustrative applications, rather than the
latest trends. In doing so, we hope that the careful reader should now be in a
position not just to understand the everyday use of cryptography, but also to
interpret future developments in cryptographic technology and applications. We
hope the case has been made that cryptography is clever, useful, important and
fun, which is a charmingly rare combination.
