All right. I was hoping that someone could help me crack a couple of
zip files with probably 50 or more known plain text bytes that are
identical at the beginning of each of these files. But I got no reply
from my original post.

So here is a paper to the point. I am hoping that one or more of you
would like to flex their crypto muscles and help me or to a lesser
extent discuss this topic for our upliftment.

http://www.woodmann.com/fravia/mike_zipattacks.htm

Thanks.

JM

Hello

Don't know if this is the right place to ask, but can anyone tell me
what values would be optimal as a 256 byte state array for the bsd
setstate, random function?

/Dacobi

I need a system to generate a series of "semi-random-non-repeating"
32-bit object IDs. For this, I plan to create a sequence counter
(starting from 0), then feed the sequence number, s, to a permutation
function, F(s). And use F(s) as the generated object ID. F() needs to
have the following properties:

1. F(x) is semi-random so that if the ID is partitioned into any
number of "buckets" (by equal range, or MOD hashing), each bucket
has roughly same number of objects.
2. F() has an inverse F' s.t. F(F'(x)) = x
3. Both F() and F'() are computationally "inexpensive" to compute

I will appreciate any help or link for such algorithm. Thanks in
advance,

Bruza