[hashcash] Re: hashcash v1 questions
- From: Adam Back <adam@xxxxxxxxxxxxxxx>
- To: hashcash@xxxxxxxxxxxxx
- Date: Tue, 1 Jun 2004 15:42:47 -0400
On Tue, Jun 01, 2004 at 06:01:14PM +0000, Justin wrote:
> On 2004-06-01T05:28:37-0400, Adam Back wrote:
> > I think we are already close to having a line-length issue, especially
> > if we include sub-puzzles. Practically you want sub-80-chars.
>
> Isn't an 80 character limit unnecessary? [...] I have a handful of
> messages with 90+ character Exchange-generated MID headers that
> aren't line-wrapped.
I just took a random sample. They mostly looked like below 80, plus a
few a-little-but-not-too-much longer.
> Is the length of the random field fixed in v1? In v0 it was fixed at 96
> bits, right?
The current v1 code does not fix it. We have discussed on the list if
it would be simpler / beneficial perhaps to fix it to 96 bits.
v0 never did fix the random field. The early implementations used a
64-bit field (which is a bit small once you get to larger collisions
because v0 combines counter and randomness field); later v0
implementations changed to 96-bit. But all v0 implementations would
accept essentially any length (subject to some sanity check of overall
stamp size).
> > Well if the postage generation is done in the background probably
> > doesn't matter so much. (Though there is some user expectation
> > potential problem -- eg dialup, I want to know when its gone so I can
> > hangup).
>
> Well that's a problem, but minting could also take much longer than
> expected with sub-puzzles.
Much less likely though. 8 or 16 sub-puzzles greatly reduces the
variance.
Adam
Other related posts:
