[hashcash] Re: libfastmint update 20040915
- From: Atom 'Smasher' <atom@xxxxxxxxxxxxxx>
- To: hashcash@xxxxxxxxxxxxx
- Date: Thu, 16 Sep 2004 04:27:00 -0400 (EDT)
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On Thu, 16 Sep 2004, Jonathan Morton wrote:
The padding places the "tail" of the count field at byte 32 or 52 (mod
64), which are the two most efficient places to calculate changes in
SHA-1 for. Most practical e-mail addresses will end up as 96-byte tokens
(32+64), though particularly short ones can be 52 bytes. If the
extension field gets substantial use, 116-byte tokens may also become
common.
==============
there seems to be "dead spots" where some stamps are generated without a
counter. these are tested using resources from 0-200 bytes with a 6 byte
date and no extension. the file shows stamps that do not have a counter
and the size of the resources used to create the stamps.
MD5 (stamps.gz) = c2e35a10d4b09c73cab049c631013df0
thoughts (after i should be in bed) about getting rid of the padding...
hhmmm... what if the padding was done internally? instead of padding the
stamp that's output, a minting application would create a stamp _as_if_ it
were padded and a verifying application would internally add appropriate
padding before calculating the hash.
ok, this would break compatibility, and no one wants to rush and create a
v2 stamp format... but an extension could exist for specifying the ~type~
of padding used (pad=x). this would still create a backwards compatibility
issue, but if time passes before that behavior is turned on by default it
shouldn't cause too many problems.
i'm going to bed soon... i promise.
...atom
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