'Person' as in Section 13

[Nicholas Bohm]

At 02:36 AM 8/7/1999 +0100, Tom Thomson wrote:
>
>> This brings up an interesting half-way house in the requirement that keys
>be
>> released when demanded by the police.  Suppose, for example, I have enough
>> information to generate a key if, and only if, I act in collusion with any
>> two other people picked from a group of five.  Do I possess the key within
>> the meaning of the Act?   If not, who does?   Any three people of the six
>> acting together surely possess the key, but no individual or pair can
>> possibly create the key.
>
>It brings up an even more interesting question: suppose any five from seven
>can deliver the key, and each of the five claims to deliver his component,
>but the resulting key will not decrypt the message.  Then it's clear that at
>least three are lying about ther component, but four could be telling the
>truth.  There's clearly no way to make a criminal charge stick against any
>individual, and even in a civil case it can be argued that 4 have complied
>and 3 have3n't so on balance of probabilities any individual is one of the
>three. (This is different from 3 out of 5 because in the 3/5 case it's clear
>that the majority are lying and that means the balance of probablities about
>any individualk is different - in theory that's irrelevant in criminal law,
>but even there it isn't irrelevant in practice in England and Wales [but
>probably is in Scotland], and it's definitely relevant in civil law unless I
>misunderstand Enlish law badly).

There have certainly been cases where the prosecution could prove no more
than that one out of two defendants committed the offence, without being
able to prove which, and without being able to prove any conspiracy.  The
result is that both are acquitted.  The same certainly seems to apply in
your example.

A combination of key splitting, steganography and communications using
transient keys will clearly defeat this proposed legislation.  If
deployment of those techniques is in fact good for security generally, and
will be promoted by the threat of the legislation, perhaps we should
welcome it after all.

Regards,

Nicholas Bohm

Salkyns, Great Canfield,
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