[clug] Passwords [SEC=UNCLASSIFIED]

[Ellis, Peter MR]

UNCLASSIFIED

Okay, let's get semi-technical military.

A. The military sometimes uses a "one-time pad" system for simple operational security (OPSEC), involving a "covered vector" (COVEC). 

This comes in several flavours, but the obvious one for this discussion is number/letter addition/subtraction.

i.e. put in a number/letter and get out a number to add/subtract to get the 'covered' number e.g. actual = 1; using the pad column for the period, get out 3; add 1+3=4.
e.g. actual = "dog"; using the pad column for the period, get out 3 (to add); get "grj" (three letters 'higher' in the alphabet). 

The principle can be used quite effectively to create scrambled and seemingly random gibberish for "short-term" encryption of time-sensitive information that has no long-term sensitivity. 


B. The other one I'll discuss: safe grids. Safes have numbers to open them, but people typically 'invent' a word or phrase then convert this to the numbers. A grid might look like this, or be 'slewed' (started down) by several lines.

1 ABC wx
2 DEF yz
3 GHI abc
4 JKL def
5 MN  ghi
6 OP  jk
7 QRS lmn
8 TU  opq
9 VW  rst
0 XYZ uv

e.g. 
CAPTURE = 1168872
capture = 3389094
CaptUre = 1389894


Use your imagination.

Peter


-----Original Message-----
From: linux-bounces at lists.samba.org [mailto:linux-bounces at lists.samba.org] On Behalf Of Keith Sayers
Sent: Monday, 27 August 2012 09:02
To: linux at lists.samba.org
Subject: Re: [clug] Passwords


	FWIW I remember once being advised that those of us who have been in the forces could use our service number - or a variant thereof.  Something you never forget ........

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Keith Sayers                                                keiths at apex.net.au
6 Clambe Place
CHARNWOOD, ACT 2615,
Australia                                       http://www.apex.net.au/~keiths
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