Cryptographically-Secured Murder Confession
From the Associated Press:
Joseph Duncan III is a computer expert who bragged online, days before authorities believe he killed three people in Idaho, about a tell-all journal that would not be accessed for decades, authorities say.
Duncan, 42, a convicted sex offender, figured technology would catch up in 30 years, “and then the world will know who I really was, and what I really did, and what I really thought,” he wrote May 13.
Police seized Duncan’s computer equipment from his Fargo apartment last August, when they were looking for evidence in a Detroit Lakes, Minn., child molestation case.
At least one compact disc and a part of his hard drive were encrypted well enough that one of the region’s top computer forensic specialists could not access it, The Forum reported Monday.
This is the kind of story that the government likes to use to illustrate the dangers of encryption. How can we allow people to use strong encryption, they ask, if it means not being able to convict monsters like Duncan?
But how is this different than Duncan speaking the confession when no one was able to hear? Or writing it down and hiding it where no one could ever find it? Or not saying anything at all? If the police can’t convict him without this confession—which we only have his word for as existing—then maybe he’s innocent?
Technologies have good and bad uses. Encryption, telephones, cars: they’re all used by both honest citizens and by criminals. For almost all technologies, the good far outweighs the bad. Banning a technology because the bad guys use it, denying everyone else the beneficial uses of that technology, is almost always a bad security trade-off.
EDITED TO ADD: Looking at the details of the encryption, it’s certainly possible that the authorities will break the diary. It probably depends on how random a key Duncan chose, although possibly on whether or not there’s an implementation error in the cryptographic software. If I had more details, I could speculate further.