staff blogs staff keep (relatively) up-to-date logs of their activities in .plan files. These were traditionally available via finger, but we've put them on the web for easier consumption.

2002-09-25 completes rc5-64 project (list announcement)

Filed under: project status — Tags: @ 00:00 +00:00


On 14-Jul-2002, a relatively characterless PIII-450 in Tokyo returned the winning key to the keyservers. The key 0x63DE7DC154F4D039 produces the plaintext output:

The unknown message is: some things are better left unread

Unfortunately, due to breakage in scripts (dbaker’s fault, naturally) on the keymaster, this successful submission was not automatically detected. It sat undiscovered until 12-Aug-2002. The key was immediately submitted to RSA Labs and was verified as the winning key.

So, after 1,757 days and 58,747,597,657 work units tested the winning key was found! While it’s debatable that the duration of this project does much to devalue the security of a 64-bit RC5 key by much, we can say with confidence that RC5-64 is not an appropriate algorithm to use for data that will still be sensitive in more than several years’ time. On the distributed computing front, however, the RC5-64 project clearly demonstrates the viability of long-term, volunteer-driven, internet-based collaborative efforts. The next time someone bemoans the public’s short attention span or need for instant gratification you should remind them what 331,252 people were able to accomplish by joining together and working for nearly five years.’s RC5-64 project clearly shows that even the most ambitious projects can be completed by volunteers thanks to the combined power of the internet and distributed computing.

Ignoring artificially high numbers resulting from network difficulties, we completed 86,950,894 workunits on our best day. This is 0.12% of the total keyspace meaning that at our peak rate we could expect to exhaust the keyspace in 790 days. Our peak rate of 270,147,024 kkeys/sec is equivalent to 32,504 800MHz Apple PowerBook G4 laptops or 45,998 2GHz AMD Athlon XP machines or (to use some rc5-56 numbers) nearly a half million Pentium Pro 200s.

Over the course of the RC5-64 project, 331,252 individuals participated. We tested 15,769,938,165,961,326,592 keys.

We apologize for the latency in the announcement, but scheduling conflicts with RSA Laboratories and difficulties in reaching the winning participant (who has asked to remain anonymous) introduced the additional delay to the process.

Also, please consider joining us on SlashNET IRC on Saturday 28-Sep-2002 @ 21:00 UTC (5:00PM EDT) for an online Q+A session on the RC5-64 project and the future plans for the network. Not only are we looking forward to moving on to RC5-72 but we’re currently reshaping the framework of the dnetc architecture to better accommodate additional projects. We’re hoping to attract some new and motivated partners with good ideas and a need for cycles.

Thanks to RSA Labs for continuing to offer challenges that reward distributed efforts!

For more information, contact:
* David McNett <> +1-512-350-5038



Official List Announcement: RC5-56 completion

Filed under: project status — Tags: @ 00:00 +00:00

It is a great privilege and we are excited to announce that at 13:25 GMT on 19-Oct-1997, we found the correct solution for RSA Labs’ RC5-32/12/7 56-bit secret-key challenge. Confirmed by RSA Labs, the key 0x532B744CC20999 presented us with the plaintext message for which we have been searching these past 250 days.

The unknown message is: It’s time to move to a longer key length

In undeniably the largest distributed-computing effort ever, the Bovine RC5 Cooperative (, under the leadership of, managed to evaluate 47% of the keyspace, or 34 quadrillion keys, before finding the winning key. At the close of this contest our 4000 active teams were processing over 7 billion keys each second at an aggregate computing power equivalent to more than 26 thousand Pentium 200’s or over 11 thousand PowerPC 604e/200’s. Over the course of the project , we received block submissions from over 500 thousand unique IP addresses.

The winning key was found by Peter Stuer with an Intel Pentium Pro 200 running Windows NT Workstation, working for the STARLab Bovine Team coordinated by Jo Hermans and centered in the Computer Science Departm ent (DINF) of the Vrije Universiteit (VUB) in Brussels, Belgium. ( Jo’s only comments were that “$1000 will buy a lot of beer” and that he wished that the solution had been found by a Macintosh, the platform that repr esented the largest portion of his team’s cracking power. Congratulations Peter and Jo!

Of the US$10000 prize from RSA Labs, they will receive US$1000 and plan to host an unforgettable party in celebration of our collective victory. If you’re anywhere near Brussels, you might want to find out when the party will be held. US$8000, of course, is being donated to Project Gutenberg ( to assist them in their continuing efforts in converting literature into electronic format for the public use. The remaining US$1000 is being retained by to assist in fund ing future projects.

Equally important are the thanks, accolades, and congratulations due to all who participated and contributed to the Bovine RC5-56 Effort! The thousands of teams and tens of thousands of individuals who have diligently tested key after key are the reason we are so successful.

The thrill of finding the key more than compensates for the sleep, food, and free time that we’ve sacrificed!

Special thanks go to all the coders and developers, especially Tim Charron, who has graciously given his time and expertise since the earliest days of the Bovine effort. Thanks to all the coordinators and keyserver operators: Chris Chiapusio, Paul Chvost ek, Peter Denitto, Peter Doubt, Mishari Muqbil, Steve Sether, and Chris Yarnell. Thanks to Andrew Meggs, Roderick Mann, and Kevyn Shortell for showing us the true power of the Macintosh and the strength of its users. We’d also like to thank Dave Avery for attempting to bridge the gap between Bovine and the other RC5 efforts.

Once again, a heartfelt clap on the back goes out to all of us who have run the client. Celebrations are in order. I’d like to invite any and all to join us on the EFNet IRC network channel #rc5 for celebrations as we regroup and set our sights on the next task. Now that we’ve proven the limitations of a 56-bit key length, let’s go one further and demonstrate the power of distributed computing! We are, all of us, the future of computing. Join the excitement as the world is forced to take notice of the power we’ve harnessed.

Moo and a good hearty laugh.

Adam L. Beberg – Client design and overall visionary
Jeff Lawson – keymaster/server network design and morale booster
David McNett – stats development and general busybody