Distributed.net is a volunteer computing effort that is attempting to solve large scale problems using otherwise idle CPU or GPU time. It is governed by Distributed Computing Technologies, Incorporated (DCTI), a non-profit organization under U.S. tax code 501(c)(3). Distributed.net is working on RC5-72 (breaking RC5 with a 72-bit key), The RC5-72 project is on pace to exhaust the keyspace in just under 47 years, although the project will end whenever the required key is found. RC5 has eight unsolved challenges from RSA Security, 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 of over 30 TFLOPS. , the throughput was estimated to be the same as a Cray XC40, as used in the Lonestar 5 supercomputer, or around 1.25 petaFLOPs. History A coordinated effort was started in February 1997 by Earle Ady 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 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. 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. 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 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