A New Crypto Challenge!
Earlier today I was introduced to the crypto challenge
that is talked about below. It originates from a CU professor (whose name I
know not), and we have VERY LITTLE TIME to solve it! There's not exactly any
prize for solving it (ahem), but I'm hoping when you see the code, you'll be as
intrigued as I am.
||3.12.2001 10:55 pm --
You can find the document that contains the original
code here. Neat, huh? (And Matt, don't go asking
me to HTMLize this mutha.. if you want another format, here it is in
So this code is an extra-credit problem for a graduate
level information-systems class at CU. Here's some of my initial thoughts:
It's an IS class, so I don't think it'll be *too* tough. If you check
the class web site
from which this sucker came, you'll see that during the course of the
course, one of the topics is 'bits and bytes'. So it may not be TOO advanced.
Here's the description from the
INFS 5030. Computer Network Design and Management.
Focuses on the backbone of an organization's information infrastructure that
ties various kinds of computers together into a coherent whole. Introduces
the component building blocks of network design such as servers, routers,
bridges, gateways, transmission media, communication protocols, network
operating systems, and middleware. Covers local area networks in some depth
and introduces metropolitan and wide-area networks. Also covers data
compression, encryption, network security, and performance tuning.
Alright, so it's not an easy course, but there can't be too much
focus on encryption.
It looks like it has been modulated with a technique called 'phase
modulation'. It is also called 'phase shift keying' or 'PSK'. This
method uses changes in phase to indicate digital bits.
We've found the following references on this sort of thing:
is short intro-type thing with fair diagrams - has info on PSK
and async transmissions.
is a good paper generally on modem communication. Talks about
async/sync methods, and PSK.
is an excellent encyclopedia of radio communications. Search
down for 'phase' - it shows how waves translate to bits. (big)
is a section from a network book on modulation.
is the WinPSK reference manual. It has information on PSK,
synchronous communication and 'varicode' characters' binary
is a primer on async modem communication from Microsoft. It talks
about the differences between sync and async communication.
So, with all that we should be able to demod the picture to binary.
Unfortunately, there could be a couple of ways to do this. Here's a
couple of pages on the different methods of PSK that we're concerned with
||3.10.2001 1:44 am --
Since there was at least some desire for it, I went ahead and set up
what is for now a read-only CVS repository
(I only have so much time to do stupid shit like this!) for the
challenge and any tools we might wanna write and distribute. If
there's some stuff you've written and would like to hand out,
feel free to email it to me and I'll put it up there. (Write access
will come later when I have a chance to setup some security or
||3.8.2001 1:55 am --
If you've actually made it down to the bottom of this page, it shows you at
least have some interest in this strange thing I've gotten myself into. The
next step is to join the mod-chal list I have setup. (That's
right, you can't crack it just yet. Dave, Ben - I'm talking to you!) Head
over to the mailing list page for further