----- Original Message -----
From: "Morlock Elloi" <[EMAIL PROTECTED]>
> > considering that people notice a matter of < 10%, people are going to
>
> Where can we observe those, pray tell ?
A great many place, but probably the place it's most easily noticed is on
the freeway (where it's also a matter of speed). When was the last time you
saw a number of people (there will of course be 1 occassionally) that
voluntarily does 10% under the speed limit? Very often (at least everywhere
I've driven, excluding rush hour) everyone does the maximum speed they can
get away with. Most often the difference between what vehicles can get away
with, and the speed people are driving is a matter of < 5% (freeway speed
limit on 101 in San Jose 65, maximum expectable speed without a ticket 70,
speed I did on the way to the restaurant for breakfast about 69, difference
1.4%). On the freeway people notice a speed difference of almost 1 %, and
it's just the first place that came to mind.
> >> Probability of the same plaintext encrypting to the same cyphertext is
1 in
> >> 65536.
> >
> > Which is no where near useful. 1 in 65536 is trivial in cryptographic
terms,
>
> Can you provide example in real file system terms where 1 in 65536 leaks
> anything ?
Sure, current disks are 80 GB or larger for a decent sized setup. Since
we've got 512 KB blocks that leaves 152587 blocks on the disk. If each block
has a 1 in 65536 chance of collision, there will be somewhere in the
neighborhood of 100000 collisions on the disk. Since on the average
businessman's computer there will be an enormous quantity of Word DOC files,
all of which have the same header (standard Word header followed by standard
letterhead), there will likely be a collision just based on those alone, at
least within a company. Each of those collisions highlights with almost
complete certainty a pair of Word Docs, which almost certainly contain
business information, which makes them the first targets. So there will be
leakage from the proposed technique.
Joe
