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Path: utzoo!utcs!lsuc!radha!sanand
From: sanand@radha.UUCP (Sanand Patel)
Newsgroups: net.crypt
Subject: Code Breaking
Message-ID: <113@radha.UUCP>
Date: Fri, 25-Apr-86 09:20:15 EST
Article-I.D.: radha.113
Posted: Fri Apr 25 09:20:15 1986
Date-Received: Sat, 26-Apr-86 06:39:18 EST
Organization: Canstar Communications
Lines: 24

Forgive my naivette, but someone mentioned that the U.S. Somebody or Other,
has essentially no problems in breaking codes (grossly paraphrased) ...
he mentioned the 'KAL' vs. Russia case.

[naive mode]

Does this apply to the simple scheme of "exclusive or" against a large
key (I know almost nothing about cryptology ...) 
e.g.

plaintext--> Some very important text that must be kept secret
My Key ----> ThisIsMySecretKeyThisIsMySecretKeyThisIsMySecretK

Coded-------> Exclusive-Or of S+T, o+h, m+i etc.

plaintext-->  Exclusive-Or of c1+T, c2+h , c3+i etc.
on other side

Now, not withstanding how the key is passed, is the above scheme breakable,
especially with very large keys (say 100 or 200 letters) ?

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