🚀 go-pugleaf

>	Doesn't this only work with a route and/or block transpositions?
	(Stuff Deleted...)
>	Incidentally, there
>	are only about 40 systematic routes through a 5x5 transposition
>	Alec Chambers.


Transposition systems that were in use back during WWII used much larger
non-square type "blocks" for example 15 x 33 characters. The characters
were read off using some route that changed from message to message. The
one I looked at used a key word derived from a common book.  The key word
expands into instructions on how to select characters from the grid.
The grid contained lots of nulls that made things more difficult to solve.

Double transposition seems to have enjoyed a vogue up until sometime in the
'50. Spys seems to have liked it in WWII, the German Secret Service for one.
One account says that with the introduction of the computers most  
transposition systems became insecure. Experts I talk to doubt that any 
transposition system arse useful except perhaps for low grade tactical 
use.

Lance Hoffman, a Prof down here at
Geo Washington Univ and author of security books thinks that 
transpositions are probabily adaquate for business privacy use (*but not all 
cases*) .  It keeps non-experts out and given the pain of decrypting one 
of these, as a hacker I would probabily not bother fooling  with a files or 
messages so rearranged. 
 
A point of triva: back in '73 one of the ciphers submitted to NBS as a 
candidate for a national data encryption standard was a multiple transposition 
cipher. It didn't win.