🚀 go-pugleaf

bbs-hrick@jwt.UUCP (Rick Harrison) writes:

>I've noticed that all the discussion of computerized cryptography
>seems to assume that one should use a byte-by-byte approach, i.e.
>take one byte of plaintext, encrypt it, output it, and repeat.
>Wouldn't it also be possible and perhaps desirable to automate
>other approaches, such as a word-by-word approach?  e.g. have a
>dictionary file containing all likely words, and replace each
>word with a 4-byte integer; plus some kind of substitution cipher
>to handle proper nouns, numerals and other things that aren't
>in the dictionary.  If the codebreakers intercepting a message
>encrypted in this manner assumed it was byte-by-byte encoded,
>they'd never be able to decrypt it.  How secure would such a
>scheme be?

Use "word or phrase" instead of "word" and you have the classic
definition of a *code* as opposed to a *cipher*. 

Statistical tests will likely be able to tell the difference.

What is more likely to occure these days is bit-by-bit rather than
character-by-character encryption.


-- 
Leonard Erickson		      leonard@qiclab.scn.rain.com
CIS: [70465,203]			 70465.203@compuserve.com
FIDO:   1:105/51	 Leonard.Erickson@f51.n105.z1.fidonet.org
(The CIS & Fido addresses are preferred)