One last question...

[Pyro]

One last question and I'll get off of your forum (as I get the feeling that's what most of you would want me to do)

anywhoo, the question:

Why crack 64 bit, instead of 128bit encryption?

 

[mechBgon]

Pyro, I think it's because that is the challenge that RSA issued and offered prize money for.

 

[Assimilator1]

Pyro

If you were to join the OGR team (thats the 1 your interested in right?🙂) , & avoid many further RC5 arguments then I'm sure you'd be welcome🙂.

 

[RaySun2Be]

Pyro,
Now THAT's a good question. 😉

I believe it has to do with the way that RSA set up their contests. 🙂

Taken from the Distributed.Net RC5 page:

<The &quot;Bovine&quot; RC5 effort was formed to take the responsibilities of coordinating and maintaining the RC5 servers that are needed to distribute key blocks to work on to all of the participating client programs. We depend heavily - entirely - on the participation of people like yourself, as we intend to solve this project via the use of brute force, trying every possible key there is.

We know this method works. On 19 October 1997 at 1325 UTC, we found the correct solution for <the previous project - RSA Labs' 56-bit secret-key challenge. (That's RC5-32/12/7 56-bit for you stats junkies.) The key was 0x532B744CC20999, and it took us 250 days to locate.>

Also here are some other links:

RSA Laboratories Challenges

RSA labs Cryptography FAQs

And feel free to ask more questions, I would just avoid asking that .... one question again. 😉

 

[Poof]

Pyro - this is not &quot;our&quot; forum - it is a Distributed Computing forum for AnandTech. Why not grab any distributed client, start it up, and see how it does on your machine...? You'll be surprised how hooked you'll get on your particular project or projects once you spend some time doing it!

🙂

 

[Sukhoi]

Well for one thing, wouldn't 128-bit encryption take exponentially longer? That's not good when 64-bit encryption is already taking over 3 years. 🙂

 

[Tetsuo316]

wow. i didn't know that the 56bit encryption only took 250 days to crack! that's not good at all! now i'm really glad that i upgraded to a 128bit encrypted browser.

 

[JHutch]

Yeah, 56-bit RC5 took 250 days... Over 3 years ago. Today, it would probably take a month, two at the most...

You see, for every bit you add, you double the complexity of the encryption. For instance RC5-57 bit (if it existed) would have taken us 500 days to finish... RC5-58 bit would have taken 1000 days to finish... etc.

That means that RC5-128 is not twice as hard to complete, as some people tend to think. It is 2^64 times harder to complete!!! That means if RC5-64 would take us 3 years to complete at today's cracking rate, RC5-128 would take...

18,446,744,073,709,551,616 (2^64) times 3 years = 55,340,232,221,128,654,848 years to finish RC5-128!!!

Anybody want to spend the next 55 quintillion years (give or take a couple years) to work on RC5-128?

😉

JHutch

 

[GeoffS]

I guess we just need to assimilate more 🙂

 

[Pyro]

<< Anybody want to spend the next 55 quintillion years (give or take a couple years) to work on RC5-128? >>



according to my estimations, it will take ~4135 years to complete RC5-64 and it will take around 76 exa years for 128(that's 76 000 000 000 000 000 000 000 years) at the current pace. Now, since both will take longer than everyones lifetime, why not just do 128?




PS, with today's rate (140 gigakeys/sec) it will take only 1 week to crack 56 bit encryption...

 

[mechBgon]

Have a look here to see the estimated time remaining to check all the RC5-64 keys. As I mentioned, it's RC5-64 that RSA is offering a prize for.

 

[narzy]

your always welcome here, if no one ever challenged why we did somthing, there would not be much to talk about around here 😛 ya sure I love hearing about the latest crackrack but it gets boring after a wile LOL :Q

we would love for you to join us, it seems that you don't like the idea of RC5 however we have many other projects, such as gamma flux (GF), GF has practical uses, trying to figue out the best way to store radio active materials, check it out www.dcypher.net

 

[JHutch]

Your estimates are a bit off, Pryo. It should take less than 3 years to exhaust the rest of the keyspace at our current rate and we'll probably find the key long before then...

Now quit TALKING about RC5 and JOIN one of the projects already! 🙂

JHutch