Re: Prosecutor cannot compel disclosure of encryption keys?


William L. Bahn wrote:
"Pubkeybreaker" <Robert_silverman@xxxxxxxxxxxx> wrote in message
news:1150417795.215766.188250@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx



And how many "home grown" encryption algorithms have ever proven
to be secure? Just because you come up with an algorithm that
*you* can't break doesn't mean that a team of other people can't
break it quickly. You sure as heck wouldn't be the first.


Sometimes I wonder if people in this newsgroup know how to read.

Nowhere in any of the prior discussion did I mention using a home grown
algorithm. I did mention using AES. Writing home-grown software
that *uses* AES is different from developing a home-grown algorithm.

But this distinction seems to elude you.


Even people - and not amateurs - who have relied on OTPs have
come to grief. Hint - Venona.

Once again, it seems you can't read. Nowhere did I say that I would
use a OTP for encryption. I mentioned the OTP because I said it could
be used (with some care) to decrypt a legitimate AES encryption into
ANYTHING desired.

And I am quite remote from being an amateur.

This is the major problem with a prosecutor demanding keys. The
suspect
can hand over a OTP key that will decrypt an AES encrypted file into
something
harmless. The suspect never hands over the legitimate key(s).

Let's assume the suspect has a file indicating names of hit-men,
names of their victims, and the amount they were paid by some mob boss.
[or some other incriminating piece of evidence]

I can see the scenario before the judge:

Judge: Mr. Prosecutor, did the murder suspect hand over the keys?
Prosecutor: He claims to have done so, but when we decrypted the
file,
it just turned out to be evidence of bookmaking, your honor. We think
he
is hiding the real keys. We are charging him with bookmaking.
Judge: How can there be two different keys?
Prosecutor: I have been told that it is possible to construct keys so
the encrypted
data will decrypt into anything at all your honor.
Judge: So you never have a way of knowing if the keys given you are
legitimate?
Prosecutor: We believe that the suspect is hiding the real keys.
Judge: What evidence do you have? Do you have any way of knowing the
real contents of the encrypted files?
Prosecutor: Just the ancillary evidence we have already presented
which
leads us to believe that we have the right suspect. We think the
suspect is lying,
your honor.
Judge: You'll have to come up with more than that. Hiding illegal
bookmaking
seems to be a prima faciae reason to encrypt data.


People can be forced to give hair samples, blood samples, DNA samples
etc. despite the 5th amendment. I am pointing out that (with care)
it would be
possible to thwart a court order to turn over crypto keys.

.

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