Unicode is the next 3|_33+ 5P34|<
Bored with being eleet on IRC? Why not take a look at
the forthcoming 32-bit eleetness brought to you by
At the Shoestring Foundation Labs, where we invented
time machines long before H.G. Wells could think of one,
we are in the process of converting boring old ASCII
to totally eleet Unicode. See our example page!.
Extended Euclidian Algorihtm in dc(1)
If you think you're really bored than guess how bored I was when I
wrote The Extended Euclidian Algorithm in a
one-line shell script.
Ok, it's a long line (160 chars in the
dc part), but it runs on every POSIX compliant system and works
on arbitrarily large numbers.
In contexts like remailers it is impossible to have the
originator of a message solve puzzles interactively. But
with quasi-synchronous clocks (exact up to a few hours perhaps)
and a small database, it is possible to implement offline
Hashcash. Such a Hashcash Check looks like:
It is bound to a recipient (email@example.com) and a date,
so presenting the same check to other parties or to the same party after
a certain period of validity will fail. For the period of validity
the recipient has to store the Rand value and compare incoming
Hashcash Checks against the list of received checks. If the Rand
is on the list or the date outside the validity, the Hashcash is ignored.
And it's all implemented in Perl.
Adam Back has a similiar
scheme with shorter messages intended to be embedded in headers of
Also called Client Puzzles. HashCash is used to prove
expenditure of computing power. This is interesting for
flooding control, e.g.
SMTP Server: You want to send this email to 10.000 recipients? Well, pay 12 bits of HashCash for each one.
Adam Back proposed and
implemented HashCash based on partial hash collisions. I wrote a
perl module that implements charge,
pay and check functions for Hashcash in interactive
Spammer's MUA: Alright, forget about it.