[RC5] DES 2 (in preparation of)

Daniel Baker dbaker at wrangler.cuckoo.com
Fri Jan 2 14:18:57 EST 1998

> Greetings All,
> I am new to all of this, though I fully support any and all efforts to prove
> that ANY type of 'encryption' can be broken and thus NO such system is safe
> enough to trust totally...

Yup. :)

> I have a few questions though, even having read the web-pages and the postings
> made since I joined this list...
> 1) As I understand it, there is a central server controlling the distribution of
> each of the quadzillion (or more) packets to be tested for the hidden message so
> that each is only processed once.  Anyone participating (ie contributing their
> spare processor time) has a client on their machine that downloads a set of
> packets when they dial-in and connect to the Internet, and uploads any completed
> 'results' from the previous batch once processed by their client - which all
> happens behind the scenes when their computer/LAN is doing nothing else.  Is
> this understanding right?

There is one "Keymaster" that has the main database and logs.  There are ~20
Full Proxies that communicate with the keymaster to get a large of amount
of work, and it hands out that work to clients.

> 2) As far as the competition is concerned, how is the 'winner' discerned?  If
> all the calculations, etc are being handled in the background, how would you
> know if one of 'your' packets held the solution?  I assume the distributing
> server keeps a record of who had what or the individual clients break into a
> 'celebration' algorythm?

Everything is logged. For every block you upload, the proxy logs it along
with other information:

12/16/97 03:54:09,,dbaker at neosoft.com,6479D55590000000,268435456,3,1,6402
    (1)     (2)       (3)            (4)              (5)             (6)   (7)(8) (9)

1: Date that the block was submitted in GMT.
2: Time that the block was submitted in GMT.
3: IP that the block was submitted from.
4: Email address that the user (I) specified in the client configuration
5: The block that was completed		
6: Basically, the results. 		(Key not found. :( )
7: Operating system 			(FreeBSD)
8: CPU Type         			(X86)
9: Client version number		(I need to upgrade. 6403 is the latest)

So, the stats server can use these types of logs to tell you how many blocks a day you're doing, etc.

Also, if a result is found, it will be added to the sucesslog on the master. The keymaster operator
will notice the success and check it for validity.  If it's the correct key, it will be sumitted to
RSA labs, and you will be shortly notified via email or telephone or something...

> 3) When up/downloading packets during a dial-in, how long will it take to
> complete the transaction?  Ie, how long @ 28k8 (for example) will the process
> need the line kept open for?

It won't saturate your connection, as trasnferring blocks to/from the proxy is a low-bandwidth
operation.  Each block requires ~120bytes to be transferred across your modem. There is also
lag at the proxy and inbetween. I usually see about a block a second.

> 4) And finally;
> >No, the current personal proxies will not support DES.
> >(ie, you can't just delete your rc5-64 buffers and have them replaced
> >with DES buffers)
> >You will need to upgrade to the DES/RC5-64 clients, and upgrade your
> >proxy.
> When and where will these programs be available?

Very shortly. An [ADMIN] post will be sent out with more information in the next week or two.

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