Distributed.net

distributed.net

Web address	distributed.net
Type of site	volunteer computing
Owner	Distributed Computing Technologies, Inc.
Launched	1997
Alexa rank	620,512 (February 2014)[2]

distributed.net (or Distributed Computing Technologies, Inc. or DCTI) is a worldwide distributed computing effort that is attempting to solve large scale problems using otherwise idle CPU or GPU time. It is officially recognized as a non-profit organization under U.S. tax code 501(c)(3).

Currently, distributed.net is working on RC5-72 (breaking RC5 with a 72-bit key),^[3] OGR-27^[4] and also has recently completed the OGR-25 and OGR-26 projects,^[5] which searched for 25- and 26-mark optimal Golomb rulers. The RC5-72 project is currently on pace to exhaust the keyspace in just over 200 years, although the project will end whenever the required key is found. Both problems are part of a series - OGR is part of an infinite series; RC5 currently has eight unsolved challenges from RSA Security, although in May 2007, RSA Security announced^[6] that they would no longer be providing prize money for a correct key to any of their secret key challenges. distributed.net has decided to sponsor the original prize offer for finding the key as a result.^[7]

In 2001, distributed.net was estimated to have a throughput of over 30 TFLOPS.^[8] Current throughput is likely to be much higher.^[9]

History

A coordinated effort was started in February 1997 by Earle Ady and Christopher G. Stach II of Hotjobs.com and New Media Labs fame, as an effort to break the RC5-56 portion of the RSA Secret-Key Challenge, a 56-bit encryption algorithm that had a $10,000 USD prize available to anyone who could find the key. Unfortunately, this initial effort had to be suspended as the result of SYN flood attacks by participants upon the server.^[10]

A new independent effort, named distributed.net, was coordinated by Jeffrey A. Lawson, Adam L. Beberg, and David C. McNett along with several others who would serve on the board and operate infrastructure. By late March 1997 new proxies were released to resume RC5-56 and work began on enhanced clients. A cow head was selected as the icon of the application and the project's mascot.^[11] The RC5-56 challenge was solved on October 19, 1997 after 250 days.^[12]

The next project was the RC5-64 challenge which took nearly five years to complete before the correct key (0x63DE7DC154F4D039) was found on July 14, 2002 decrypting the message to the plaintext "some things are better left unread".^[13]

The distributed.net client

"dnetc" is the file name of the software application which users run to participate in any active distributed.net project. It is a command line program with an interface to configure it, available for a wide variety of platforms. distributed.net refers to the software application simply as the "client". As of May 2009, 32-bit Windows on Intel x86 is the most used configuration, with Linux on Intel x86 in second place, and Mac OS X on PowerPC in third place.^[14]

Portions of the source code for the client are publicly available, although users are not permitted to distribute modified versions themselves.^[15]

Development of GPU-enabled clients

Average daily RC5-72 production by platform for 27 November 2013 – 1 January 2014^[1]

In recent years, most of the work on the RC5-72 project has been submitted by clients that run on the GPU of modern graphics cards. Although the project had already been underway for almost 6 years when the first GPUs began submitting results, as of January 2014, GPUs represent over 69% of all completed work units,^[16] and currently complete almost 90% of all work units each day.^[1]

• NVIDIA

In late 2007, work began on the implementation of new RC5-72 cores designed to run on NVIDIA CUDA-enabled hardware, with the first completed work units reported in November 2008. On high-end NVIDIA video cards, upwards of 600 million keys/second has been reported.^[17] Considering a very high end single CPU working on RC5-72 may achieve 50 million keys/second, the CUDA advancement represents a performance increase of roughly 1000%. As of January 2014, more than 4% of all work on the RC5-72 project has been completed by Nvidia GPUs,^[16] and Nvidia GPUs complete 5 to 15% of all work units each day (see OpenCL section).^[1]

• ATI

Similarly, near the end of 2008, work began on the implementation of new RC5-72 cores designed to run on ATI Stream-enabled hardware. Some of the products in the Radeon HD 5000 and 6000 series provide key rates in excess of 1.8 billion keys/second.^[18] As of January 2014, almost 65% of all work on the RC5-72 project has been completed by AMD GPUs,^[16] and AMD GPUs complete 75 to 85% of all work units each day (see OpenCL section).^[1]

• OpenCL

An OpenCL client entered beta testing in late 2012 and was released in 2013. As of January 2014, OpenCL clients produce roughly 10% of all work units each day.^[1] No breakdown of OpenCL production by GPU manufacturer exists (AMD and Nvidia GPUs support OpenCL), making it impossible to determine exact RC5-72 production numbers for AMD and Nvidia GPUs.

Timeline of distributed.net projects

Timeline of projects hosted by distributed.net, as of January 2014

Current

• RSA Lab's 72-bit RC5 Encryption Challenge — In progress, 3.066% complete as of 1 January 2014^[19] (although RSA Labs has discontinued sponsorship)
• Optimal Golomb Rulers (OGR-27) — In progress, ~97.78% complete as of 1 January 2014^[20]

Cryptography

• RSA Lab's 56-bit RC5 Encryption Challenge — Completed 19 October 1997 (after 250 days and 47% of the key space tested).
• RSA Lab's 56-bit DES-II-1 Encryption Challenge — Completed 24 February 1998 (after 39 days)^[21]
• RSA Lab's 56-bit DES-II-2 Encryption Challenge — Ended 17 July 1998 (found independently by the EFF DES cracker after 2.5 days)
• RSA Lab's 56-bit DES-III Encryption Challenge — Completed 19 January 1999 (after 22.5 hours with the help of the EFF DES cracker)
• CS-Cipher Challenge — Completed 16 January 2000 (after 60 days and 98% of the key space tested).^[22]
• RSA Lab's 64-bit RC5 Encryption Challenge — Completed 14 July 2002 (after 1757 days and 83% of the key space tested).^[12]

Golomb rulers

• Optimal Golomb Rulers (OGR-24) — Completed 13 October 2004^[23] (after 1552 days)
• Optimal Golomb Rulers (OGR-25) — Completed 24 October 2008^[24] (after 3006 days)
• Optimal Golomb Rulers (OGR-26) — Completed 24 February 2009^[25] (after 121 days)

See also

• RSA Secret-Key Challenge
• Golomb Ruler
• DES Challenges
• Brute force attack
• Cryptanalysis
• Key size
• List of distributed computing projects

References

External links

• Official website
• The RSA Laboratories Secret-Key Challenge (no longer active)