Paper and State - Burdens of Proof - page 134

working group, I submitted in April 2001 a memo outlining significant
concerns with the long-term preservation of signed electronic authentic
acts. The memo noted that the cryptographic signature model failed to
distinguish between two distinct contexts for verification: the first one,
when Bob initially receives the document, and the second one, during liti-
gation, when the document is presented to the judge as evidence. This
later verification may occur years after signature creation—in fact, poten-
tially as many years as specified by retention requirements for the docu-
ment in question. Given this possibility, litigation also requires solutions
to the long-term legibility of electronic documents in the face of constant
hardware and software obsolescence.
This issue of digital preservation has emerged in recent years as one of
the most significant and troubling challenges posed by computerization.
Although there is at this stage little experience or theoretical discussion of
its implications, a widespread strategy relies on periodic migrations of
documents' encoding formats. In order to fight off technological obsoles-
cence, one might choose to convert a document encoded in a proprietary
word processing format (say, Word 5.1) to either a more manageable open
standard (say, PDF) or a more recent version of the format (say, Word 6). 27
This is problematic: given cryptographic signature verification fails if a
single bit of the signed message is modified, the verification cannot distin-
guish between those modifications motivated by malicious intervention
and those motivated by archival preservation procedures. For signature
verification to perform its forensic truth in the course of litigation, the
signed document must thus be frozen in its original state. In other words,
one can preserve the ability to verify the original signature or one can
ensure the document remains legible over time, but one cannot do both at
the same time . 28 Given the requirements for unlimited archiving of authentic
acts, this presented a serious hurdle. Even if such issues could be resolved,
it seemed likely that the long-term preservation of electronic authentic acts
would require means beyond the ability of individual professionals, and
that more centralized forms of archiving would need to emerge.
Toward the First Electronic Authentic Act
The working group's final report was submitted to the Ministry of Justice
in the fall of 2001. By then, the blaze that had been the New Economy
was already smoldering, and the impetus for rapid and radical adaptation