failure to deliver message in readable form (Re: Encrypting to self)

[Adam Back]

Ian Batten writes:
> Would it be reasonable to hold that the sender of a letter
> which was subsequently destroyed should be able to produce a
> copy?  A copy, moreover, which they can show is authentic?
> Of course not.

Right.

> Since most people avoid dealing with fraudsters and criminals, the
> only way you could protect yourself in this case would be to keep
> notarised copies of everything you send.

Clearly impractical.

> But wait!  What about phone calls?  Suppose it's shown that
> innocent you phoned a suspect, and the law enforcement
> agencies didn't record the call (perhaps they hadn't got a
> warrent at that point, which would of course remove any
> possibility of the line being tapped).  You can't off-hand
> recall the content of the call.  Should you have taped it?

Of course not.

> And so on.  It's all total nonsense.

Agreed, and I hope that DTI will consider practicalities such as this.

Any wording to require decryption needs to be tempered with
considerations such as:

- a right not to incriminate oneself
- did the person have the key to start with -- is there any proof
  indicating this
- did the software automatically delete the key as part of the
  protocol (temporary and short lived keys are common in existing
  protocols)
- does a third party have an obligation to help the police with
  investigative work
- can an ISP be deputised to place wire taps, or to perform active
  attacks against it's subscribers

My thoughts are that if police break and enter a property, and take
equipment, printed material and electronic material, that it is
_their_ problem to understand that material.  To require the person
being investigated to explain documents meanings, etc. is yet more
erosion of the right to remain silent.  In my view it was a big step
backwards to water down the right to remain silent as it has been so
far.

(The right to remain silent was weakened apparenty motivated by lack of
evidence allowing some terrorists to escape prosecution.  To me this
suggests that the terrorists ought to be allowed to go free -- after
all if there is no evidence what else are they suggesting.)

Adam