From daw@espresso.CS.Berkeley.EDU Sun Mar 17 00:43:37 PST 1996
Article: 612 of sci.crypt.research
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From: daw@espresso.CS.Berkeley.EDU (David A Wagner)
Newsgroups: sci.crypt.research
Subject: ECB o CFB = CBC
Date: 12 Mar 1996 04:54:25 GMT
Organization: University of California, Berkeley
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Has anyone ever noticed that ECB o CFB = CBC?
 
In other words, encrypting a message with CFB mode followed by ECB mode gives
you a perfectly valid CBC encryption of the original message.  Cute, eh?
 
This seems like a surprising interaction between different modes of operation.
Can anyone see any applications (or attacks) based on this idea?
 
Is this already well-known in the folklore?