MS Word and (unintended) steganography

[Nicholas Bohm]

At 12:02 19/05/2001 +0000, Graham Murray wrote:
>Nicholas Bohm <nbohm@ernest.net> writes:
>
>> Suppose that the word file described below had been digitally signed, and
>> in legal proceedings the signature had been admitted as evidence of its
>> authenticity (including the signatory's intention that it have legal effect
>> - see ECA 2000 subsection 15(2)(a)(iii)).  How does the court decide what
>> the signature proves the signatory to have intended to have legal effect?
>> The answer depends on the evidence of the signatory, no doubt supported by
>> the surrounding correspondence, and perhaps on expert evidence about what
>> the signatory probably saw himself as signing.
>
>Would it not be better if the court decided that the signature covers
>*all* of the content? After all, unlike an ink signature, the digital
>signature verifies that the presented data is the same as that which
>was signed and has not been subsequently altered. The person
>generating the signature has signed the complete document, not just
>the text which would be printed by the Word application. Maybe a few
>such decisions plus action by Data Protection (for releasing personal
>data in the "hidden" parts of the document) would make
>people/companies take more care in selecting the formats used to
>exchange documents. 

Perhaps; but I doubt that the courts would lend themselves to this.  After
all, if you sign a paper document which unknown to you has hidden writing
in invisible ink, a court wouldn't treat you as having signed what you
hadn't seen.

Regards

Nicholas

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