Distributed.net is a

volunteer computing Volunteer computing is a type of distributed computing in which people donate their computers' unused resources to a research-oriented project, and sometimes in exchange for credit points. The fundamental idea behind it is that a modern desktop ...

effort that is attempting to solve large scale problems using otherwise idle CPU or

GPU A graphics processing unit (GPU) is a specialized electronic circuit designed for digital image processing and to accelerate computer graphics, being present either as a discrete video card or embedded on motherboards, mobile phones, personal ...

time. It is governed by Distributed Computing Technologies, Incorporated (DCTI), a

non-profit organization A nonprofit organization (NPO), also known as a nonbusiness entity, nonprofit institution, not-for-profit organization, or simply a nonprofit, is a non-governmental (private) legal entity organized and operated for a collective, public, or so ...

under U.S. tax code

501(c)(3) A 501(c)(3) organization is a United States corporation, Trust (business), trust, unincorporated association or other type of organization exempt from federal income tax under section 501(c)(3) of Title 26 of the United States Code. It is one of ...

. Distributed.net is working on

RC5 In cryptography, RC5 is a symmetric-key block cipher notable for its simplicity. Designed by Ronald Rivest in 1994, ''RC'' stands for "Rivest Cipher", or alternatively, "Ron's Code" (compare RC2 and RC4). The Advanced Encryption Standard (AES) ...

-72 (breaking RC5 with a 72-bit key). The RC5-72 project is on pace to exhaust the keyspace in just under 37 years as of January 2025, although the project will end whenever the required key is found. RC5 has eight unsolved challenges from

RSA Security RSA Security LLC, formerly RSA Security, Inc. and trade name RSA, is an American computer security, computer and network security company with a focus on encryption and decryption standards. RSA was named after the initials of its co-founders, ...

, although in May 2007, RSA Security announced 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. In 2001, distributed.net was estimated to have a

throughput Network throughput (or just throughput, when in context) refers to the rate of message delivery over a communication channel in a communication network, such as Ethernet or packet radio. The data that these messages contain may be delivered ov ...

of over 30

TFLOPS Floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance in computing, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate measur ...

. , the throughput was estimated to be the same as a

Cray XC40 The Cray XC40 is a massively parallel multiprocessor supercomputer manufactured by Cray. It consists of Intel Haswell Xeon processors, with optional Nvidia Tesla or Intel Xeon Phi accelerators, connected together by Cray's proprietary "Ar ...

, as used in the Lonestar 5 supercomputer, or around 1.25 petaFLOPs.

History

A coordinated effort was started in February 1997 by

Earle Ady Earle may refer to: * Earle (given name) * Earle (surname) Places * Earle, Arkansas, a city in Crittenden County, Arkansas, US * Earle, Indiana, an unincorporated town in Vanderburgh County, Indiana, US * Earle, Northumberland, a settlement in Ber ...

and Christopher G. Stach II of Hotjobs.com and New Media Labs, as an effort to break the RC5-56 portion of the RSA Secret-Key Challenge, a 56-

bit The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...

encryption In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...

algorithm that had a $10,000

USD The United States dollar (symbol: $; currency code: USD) is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it int ...

prize available to anyone who could find the key. Unfortunately, this initial effort had to be suspended as the result of

SYN flood A SYN flood is a form of denial-of-service attack on data communications in which an attacker rapidly initiates a connection to a server without finalizing the connection. The server has to spend resources waiting for half-opened connections, wh ...

attacks by participants upon the server. 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 Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are called co ...

head was selected as the icon of the application and the project's mascot. The RC5-56 challenge was solved on October 19, 1997, after 250 days. The correct key was "0x532B744CC20999" and the plaintext message read "The unknown message is: It's time to move to a longer key length". The RC5-64 challenge was solved on July 14, 2002, after 1,757 days. The correct key was "0x63DE7DC154F4D039" and the plaintext message read "The unknown message is: Some things are better left unread". The search for Optimal Golomb Rulers (OGRs) of order 24, 25, 26, 27 and 28 were completed by distributed.net on 13 October 2004, 25 October 2008, 24 February 2009, 19 February 2014, and 23 November 2022 respectively.

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". , volunteers running 32-bit Windows with AMD FireStream enabled GPUs have contributed the most processing power to the RC5-72 project and volunteers running 64-bit Linux have contributed the most processing power to the OGR-28 project. Portions of the source code for the client are publicly available, although users are not permitted to distribute modified versions themselves. Distributed.net's RC5-72 project is available on the

BOINC The Berkeley Open Infrastructure for Network Computing (BOINC, pronounced rhymes with "oink") is an open-source middleware system for volunteer computing (a type of distributed computing). Developed originally to support SETI@home, it became the ...

client through the Moo! Wrapper.

Development of GPU-enabled clients

In recent years, most of the work on the RC5-72 project has been submitted by clients that run on the

of modern

graphics cards A graphics card (also called a video card, display card, graphics accelerator, graphics adapter, VGA card/VGA, video adapter, display adapter, or colloquially GPU) is a computer expansion card that generates a feed of graphics output to a displa ...

. Although the project had already been underway for almost 6 years when the first GPUs began submitting results, as of January 2025, GPUs represent 88% of all completed work units, and complete more than 95% of all work units each day. *NVIDIA :In late 2007, work began on the implementation of new RC5-72 cores designed to run on

NVIDIA Nvidia Corporation ( ) is an American multinational corporation and technology company headquartered in Santa Clara, California, and incorporated in Delaware. Founded in 1993 by Jensen Huang (president and CEO), Chris Malachowsky, and Curti ...

CUDA In computing, CUDA (Compute Unified Device Architecture) is a proprietary parallel computing platform and application programming interface (API) that allows software to use certain types of graphics processing units (GPUs) for accelerated gene ...

-enabled hardware, with the first completed work units reported in November 2008. On high-end NVIDIA video cards at the time, upwards of 600 million keys/second was observed For comparison, a 2008-era high-end single

CPU A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...

working on RC5-72 achieved about 50 million keys/second, representing a very significant advancement for RC5-72. As of January 2025, CUDA clients have completed almost 11% of all work on the RC5-72 project, and perform about 9% of the work each day. *AMD / ATI :Similarly, near the end of 2008, work began on the implementation of new RC5-72 cores designed to run on

AMD FireStream AMD FireStream was AMD's brand name for their Radeon-based product line targeting stream processing and/or GPGPU in supercomputers. Originally developed by ATI Technologies around the Radeon X1900 XTX in 2006, the product line was previously br ...

-enabled hardware. Some of the products in the Radeon HD 5000 and 6000 series provided key rates in excess of 1.8 billion keys/second. As of January 2025, FireStream clients have completed over 21% of all work on the RC5-72 project. Daily production from FireStream clients has dropped below 0.5% as the majority of AMD GPU contributors now use the OpenCL client. *OpenCL :An

OpenCL OpenCL (Open Computing Language) is a software framework, framework for writing programs that execute across heterogeneous computing, heterogeneous platforms consisting of central processing units (CPUs), graphics processing units (GPUs), di ...

client entered beta testing in late 2012 and was released in 2013. As of January 2025, OpenCL clients have completed more than 56% of all work on the RC5-72 project, and now perform almost 86% of the work each day. No breakdown of OpenCL production by GPU manufacturer exists, as AMD, NVIDIA, and Intel GPUs all support OpenCL.

Timeline of distributed.net projects

; Current * RSA Lab's 72-bit RC5 Encryption Challenge started 3 December 2002 — ''In progress'', 13.228% complete as of 4 January 2025 (although RSA Labs has discontinued sponsorship) ; 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 23 February 1998'' (after 39 days) * RSA Lab's 56-bit DES-II-2 Encryption Challenge — ''Ended 15 July 1998'' (found independently by the

EFF DES cracker In cryptography, the EFF DES cracker (nicknamed "Deep Crack") is a machine built by the Electronic Frontier Foundation (EFF) in 1998, to perform a brute force search of the Data Encryption Standard (DES) cipher's key space – that is, to dec ...

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). * RSA Lab's 64-bit RC5 Encryption Challenge — ''Completed 14 July 2002'' (after days and 83% of the key space tested). ; Golomb rulers * Optimal Golomb Rulers (OGR-24) — ''Completed 13 October 2004'' (after days, confirmed predicted best ruler) * Optimal Golomb Rulers (OGR-25) — ''Completed 24 October 2008'' (after days, confirmed predicted best ruler) * Optimal Golomb Rulers (OGR-26) — ''Completed 24 February 2009'' (after days, confirmed predicted best ruler) * Optimal Golomb Rulers (OGR-27) — ''Completed 19 February 2014'' (after days, confirmed predicted best ruler) * Optimal Golomb Rulers (OGR-28) — ''Completed 23 November 2022'' (after days, confirmed predicted best ruler)

References

External links