CODES and codebreaking

MONO-ALPHABETIC substitution detection
Makes a histographic display of the text letters. so, if a mono-alphabetic substitution has taken place, the predominant characters will appear to the left of the histogram. (NOTE: Makes and Uses HTML5 canvas).
Usage: save awk program as freq_bars.awk,

LINK to: LETTER FREQUENCY generator AWK program sorce code
Create text file of monoalphabetic text: input.txt
Then run in MAC terminal, UNIX/LINIX shell:

awk -f freq_bars.awk < input.txt > output.html

then click on output.html.
Monoalphabetic texts will show a proponderance of higher counts to the left .
Polyalpahbetic or non ENGLISH/GREMAN/FRENCH texts will have a different pattern.

One-Time-Pad Encrytpion system
Program sequence:
  • Deletes all word spaces.
  • Adds a pre and postamble.
  • Adds ASCII character of a text to the ASCII charcter number of another text, then deducts 100 from the number.
  • Final task: Letter position transposition on all characters.

The addative cypher is generaly assumed by cryptography experts to be essentialy unbreakable, becasue

  • The key is not generated or re-cycled.
  • The key is as long as the message.
  • Possible candidate substitute character are ambigious. Any substitution produces infinite possibilites of the plaintext.
  • Word spaces are removed, so any kind of word analysis is impossible.
  • Security of the cypher depends on the management of the private text keys and their distribution and storage
The user supplies and distribute their own addative-text keys. Addative text need to be at least as long as the message, not randomly generated, as all known random-number generators are based on not-really-random algorithims.
As an alternative to distributiong key tests, daily news texts published by third parties can be used, as long as they are NOT RE-USED. Security in this case is dependant on maintaining secrecy of which documents are being used as keys.

Recmmended user actions to maintian security.

  • System manager to supply key texts.
  • Cypher machine passworded.
  • Key text(s) placed on air-gapped decrytping machine (never been, not capable of being networked).
  • 57+ cycle deletion programs recommened to erase kesy and messages from all user machinery
  • Hard drives returned to company for physical destruction after use.
  • Extent of key selection would depend on the length of time the message is important. Lower security on key selection (Commerical web-texts), could be permitted when the messages is valueless after s specific time, as message breaking might be possible if some guess as to the key text could be made.

Computer-Aided Design Projects

META FORMAT of CAD Part Data. A method of defining CAD component data in a CAD-system neutral format.
CAD DATA distribution. A method of defining instances or versions of CAD data, versioning, locking, modifying and archiving component DATA
Data Version and Recursion Concepts of Part/Component management , a pre-requisite for part-data distribution

Hardware repair notes

ERICSSON / HP320LX Palmtop repair guide Back to techniques and services