distributed.net is a world-wide distributed computing effort that is attempting to solve large scale problems using otherwise idle CPU time.

It started out as an effort to break RC5-56, a 56-bit encryption algorithm that had a $10,000 USD prize available to anyone who could find the key. That challenge was solved on October 19 1997 after 250 days. The next project was the RC5-64 challenge which took nearly five years to complete before the correct key was found on July 14 2002.

Currently, distributed.net is working on RC5-72 (breaking RC5 with a 72-bit key), and the OGR-25 project, which is searching for 25 point optimal Golomb rulers.

Official Projects

• Optimal Golomb Rulers (OGR-24) — Completed October 13 2004 [1]
• Optimal Golomb Rulers (OGR-25) — In progress
• RSA Lab's 56-bit RC5 Encryption Challenge — Completed October 19 1997 (after 250 days and 47% of the key space tested).
• RSA Lab's 64-bit RC5 Encryption Challenge — Completed July 14 2002 (after 1757 days and 83% of the key space tested).
• RSA Lab's 72-bit RC5 Encryption Challenge — In progress
• CS-Cipher Challenge — Completed January 16 2000 (after 60 days and 98% of the key space tested).
• RSA Lab's 56-bit DES-III Encryption Challenge — Completed January 19 1999 (after 22.5 hours with the help of EFF's Deep Crack custom DES cracker)
• RSA Lab's 56-bit DES II-2 Encryption Challenge — Ended July 17 1998 (found independently by EFF's Deep Crack custom DES cracker after 2.5 days)
• RSA Lab's 56-bit DES II-1 Encryption Challenge — Completed February 24 1998 (after 39 days)

See also

• Brute force attack
• Cryptanalysis
• Key size

External links

• Official website
• The RSA Laboratories Secret-Key Challenge