As I understand it, Adobe used ECB mode, which means the blocks are encrypted independently. You can look at the encrypted blocks and see that two different pas

As I understand it, Adobe used ECB mode, which means the blocks are encrypted independently. You can look at the encrypted blocks and see that two different passwords share character sequences. This is I assume what Randall is referring to with the 'crossword' bit - as well as having clues in the hints, solving one password may give you part of another. The suffix may also contain only one or two characters (plus padding) which makes it more plausible to mount a brute force attack. ECB mode is just terrible. As well as these suffix problems, I've seen another example where a company used it to encrypt key-value pair cookies. Of course the keys are always the same...so prefixes were guessable too. And wikipedia has a fantastic example of why its stupid for images: http://en.wikipedia.org/wiki/ECB_mode#Electronic_codebook_.28ECB.29 http://en.wikipedia.org/wiki/ECB_mode#Electronic_codebook_.2...