but I have a question: how did they know it was his diary?
If I remember some earlier discussion about that case from a few years ago, the file was called "diary.pgp".
how did they know it was *his* diary?
Well, nobody *knows*. But if you've got a file called diary.pgp on your hard drive, chances are it's a diary of some sort. It's a reasonable guess.
Whether there's anything incriminating in it for him or anyone else is another matter, of course.
all my respondents seem to be missing some basic points I have been trying to make about law enforcement in the US. the law runs on proof, and evidence. a file with the name "diary.pgp" is not incriminating. it is not evidence. no one could be prosecuted as a criminal for having a diary. there is the presumption of innocence unless there is evidence and proof to the contrary. furthermore, suppose the "pedophile" is actually prosecuted successfully. does that mean the diary was incriminating? no, it does not. in the CA case it happened that the pedophile was prosecuted without decrypting the diary. which in fact argues in favor of the side that says, "cryptography is not the end of law enforcement, and this case proves it." as packwood demonstrates, it is easy to have a diary that one would want to encode to hide embarrassing information that is not necessarily incriminating. now, a person might be successfully prosecuted for obstruction of justice, or contempt of court, in refusing to hand over the decrypted diary (but the other post I made about giving the federal agents a key that decrypts the file to a cookie recipe handles this quite nicely). somebody-or-other objected that the police are not likely to "buy it" if such a situation occurs. well, excuse me, but WHAT IS YOUR POINT? are you suggesting that they are now going to have to resort to torture or something to elicit the real key? last I checked, torture was illegal in our country... please, will people stop sending me responses like the above? do you understand how the American legal system works? a person cannot be prosecuted without evidence. evidence cannot be illegally obtained. a person is not required to testify against oneself. these are all basic long-established cornerstones of our legal system. look, if someone WANTS to be put in jail for having encrypted files, I'm sure you can probably figure out some way to pull it off. but if you don't act like an idiot, such a thing is highly unlikely. it clearly has not happened to date. I am really amazed at all the times when I point out basic limitations on e.g. the NSA or the law enforcement agencies, and somebody says, well yes BUT so-and-so hypothetical situation might arise. it is almost as if some people here have a secret "prosecute me" wish. why is there such deep fear around here about life in the US today? I'd say that people here are high up on the list of creating the paranoia. be careful what you fear, you might get it.