In a blatant attempt to get some PR:
In a new paper, Bernd Roellgen of Munich-based encryption outfit PMC Ciphers, explains how it is possible to compare an encrypted backup image file made with almost any commercial encryption program or algorithm to an original that has subsequently changed so that small but telling quantities of data 'leaks'.
Here's the paper. Turns out that if you use a block cipher in Electronic Codebook Mode, identical plaintexts encrypt to identical ciphertexts.
Yeah, we already knew that.
And -1 point for a security company requiring the use of Javascript, and not failing gracefully for a browser that doesn't have it enabled.
And -- ahem -- what is it with that photograph in the paper? Couldn't the researchers have found something a little less adolescent?
For the record, I doghoused PMC Ciphers back in 2003:
PMC Ciphers. The theory description is so filled with pseudo-cryptography that it's funny to read. Hypotheses are presented as conclusions. Current research is misstated or ignored. The first link is a technical paper with four references, three of them written before 1975. Who needs thirty years of cryptographic research when you have polymorphic cipher theory?
EDITED TO ADD (10/9): I didn't realize it, but last year PMC Ciphers responded to my doghousing them. Funny stuff.
