[XeTeX] \(pdf)mdfivesum

mskala at ansuz.sooke.bc.ca mskala at ansuz.sooke.bc.ca
Thu Jul 2 06:54:05 CEST 2015

On Thu, 2 Jul 2015, Ross Moore wrote:
> MD5 sums are also required pieces of data with some of the modern PDF
> standards, such as PDF/A, PDF/UA, and especially whenever attachments
> are included. They are part of the bookkeeping data that can be used to
> ensure that embedded files are indeed what was intended, and have not
> been intercepted and changed by Malware.

If MD5 is necessary for compatibility with some existing standard, so be
it; but it's not secure anymore and it shouldn't be used in any new design
where there's a concern about possible deliberate tampering, as opposed to
accidental errors.  SHA1 is deprecated, too.  I think SHA256 is the
current "best practice."

Matthew Skala
mskala at ansuz.sooke.bc.ca                 People before principles.

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