Not the law, but a good idea.
Port knocking: a stealthy system for network authentication across closed ports
Port Knocking has not been seen on TV


Perl prototype: v0.30

  • pcaplib support added; daemon no longer requires firewall log file

2004-Nov-14 18:59 | ...more

new Net::Pcap support added to sniff packets directly ...more

Links to related and background articles, guides, standards, documents, sites and books.


Handbook of Applied Cryptography
Alfred J Menezes, Paul C van Oorschot, Scott A. Vanstone

excerpt | This book is intended as a reference for professional cryptographers, presenting the techniques and algorithms of greatest interest to the current practitioner, along with the supporting motivation and background material. It also provides a comprehensive source from which to learn cryptography, serving both students and instructors. In addition, the rigorous treatment, breadth, and extensive bibliographic material should make it an important reference for research professionals.

Applied Cryptography
Bruce Schneier

excerpt | This new edition of the cryptography classic provides you with a comprehensive survey of modern cryptography. The book details how programmers and electronic communications professionals can use cryptography -- the technique of enciphering and deciphering messages -- to maintain the privacy of computer data. It describes dozens of cryptography algorithms, gives practical advice on how to implement them in cryptographic software, and shows how they can be used to solve security problems. Covering the latest developments in practical cryptographic techniques, this new edition shows programmers who design computer applications, networks, and storage systems how they can build security into their software and systems.

Modern Cryptography: Theory and Practise
Wenbo Mao

excerpt | Wenbo Mao explains why "textbook" crypto schemes, protocols, and systems are profoundly vulnerable by revealing real-world-scenario attacks. Next, he shows how to realize cryptographic systems and protocols that are truly "fit for application"--and formally demonstrates their fitness. Mao presents practical examples throughout and provides all the mathematical background you'll need.

Mao introduces formal and reductionist methodologies to prove the "fit-for-application" security of practical encryption, signature, signcryption, and authentication schemes. He gives detailed explanations for zero-knowledge protocols: definition, zero-knowledge properties, equatability vs. simulatability, argument vs. proof, round-efficiency, and non-interactive versions.

Coverage includes:

  • Crypto foundations: probability, information theory, computational complexity, number theory, algebraic techniques, and more
  • Authentication: basic techniques and principles vs. misconceptions and consequential attacks
  • Evaluating real-world protocol standards including IPSec, IKE, SSH, TLS (SSL), and Kerberos
  • Designing stronger counterparts to vulnerable "textbook" crypto schemes

Linux Security

Securing and Optimizing Linux: The Ultimate Solution
Gerhard Mourani

excerpt | There are no royalty or licensing fees for using Linux, and the source code can be modified to fit your needs. The results can be sold for profit, but original authors retain copyright and you must provide the source to your modifications.

Because it comes with source code to the kernel, it is quite portable. Linux runs on more CPUs and platforms than any other computer operating system. The recent direction of the software and hardware industry is to push consumers to purchase faster computers with more system memory and hard drive storage. Linux systems are not affected by those industries orientation because of it capacity to run on any kind of computers, even aging x486-based computers with limited amounts of RAM.

Linux is a true multi-tasking operating system similar to its brother UNIX. It uses sophisticated, state-of-the-art memory management to control all system processes. That means that if a program crashes you can kill it and continue working with confidence.

Another benefit is that Linux is practically immunized against all kinds of viruses that we find in other operating systems. To date we have found only two viruses that were effective on Linux systems.


Codes and Ciphers - Julius Caesar, the ENIGMA, and the Internet
Robert Churchhouse

sample chapter | excerpt | The design of code and cipher systems has undergone major changes in modern times. Powerful personal computers have resulted in an explosion of e-banking, e-commerce and e-mail, and as a consequence the encryption of communications to ensure security has become a matter of public interest and importance. This book describes and analyses many cipher systems ranging from the earliest and elementary to the most recent and sophisticated, such as RSA and DES, as well as wartime machines such as the ENIGMA and Hagelin, and ciphers used by spies. Security issues and possible methods of attack are discussed and illustrated by examples. The design of many systems involves advanced mathematical concepts and this is explained in detail in a major appendix. This book will appeal to anyone interested in codes and ciphers as used by private individuals, spies, governments and industry throughout history and right up to the present day.

Neil Stephenson

excerpt | The orders arrive encrypted into groups of five random-looking letters, printed out on the blue tissue paper that is used for top-secret cablegrams. The message has been encrypted in Washington using a one-time pad, which is a slow and awkward but, in theory, perfectly unbreakable cipher used for the most important messages. Waterhouse knows this because he is one of the only two persons in Pearl Harbor who has clearance to decrypt it. The other one is Commander Schoen, and he is under sedation today. The duty officer opens up the appropriate safe and gives him the one-time pad for the day, which is basically a piece of graph paper covered with numbers printed in groups of five. The numbers have been chosen by secretaries in a basement in Washington by shuffling cards or drawing chits out of a hat. They are pure noise. One copy of the pure noise is in Waterhouse's hands, and the other copy is used by the person who encrypted this message in Washington.

last updated 2005-Jan-01 16:51
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