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Current Projects


Having successfully completed RC5-56 and RC5-64, we are now working on the 72-bit variant of this encryption algorithm! More information is available on the RC5 Project Page.

Optimal 28-Mark Golomb Rulers:

Essentially, a Golomb Ruler is a mathematical term given to a set of whole numbers where no two pairs of numbers have the same difference. An Optimal Golomb Ruler (OGR) is just like an everyday ruler, except that the marks are placed so that no two pairs of marks measure the same distance. OGR's have many uses in the real world; for more information about them and the status of the project, please visit our pages devoted to our OGR effort.

Possible Future Projects

RSA Prime Factoring:

The inability to quickly factor large composite numbers into its prime factors is one of the underlying assumptions of many cryptographic systems. RSA Labs previously sponsored a series of challenges to factor successively larger numbers, each with an increasing prize amount. However, they have discontinued prize sponsorship.

Fermat Numbers:

Factor Fermat numbers.

Elliptic Curve Cryptosystem (ECC):

Another cryptography challenge.

Your project here!

If you have a problem that requires a large amount of computing power and can be cut into many small pieces.. write to us!

Past Projects

Optimal 27-Mark Golomb Rulers:

The OGR-27 project was officially concluded on 25-Feb-2014 in the public announcement. We proved that 27/3-12-26-25-29-2-9-36-10-68-1-4-17-53-35-8-16-28-6-14-13-71-18-19-23-7 was the most optimal 27-mark ruler possible.

Optimal 26-Mark Golomb Rulers:

The OGR-26 project was officially concluded on 24-Feb-2009 in the public announcement. We proved that 26/1-32-50-21-6-14-39-22-15-3-46-2-7-56-4-25-13-30-44-10-16-8-11-12-5 was the most optimal 26-mark ruler possible.

Optimal 25-Mark Golomb Rulers:

The OGR-25 project was officially concluded on 25-Oct-2008 in the public announcement. We proved that 25/12-17-10-33-19-55-11-3-1-5-25-16-7-44-32-26-38-18-22-2-35-28-8-13 was the most optimal 25-mark ruler possible.

Optimal 24-Mark Golomb Rulers:

The OGR-24 project was officially concluded on 1-Nov-2004 in the public announcement. We proved that 24/9-24-4-1-59-25-7-11-2-10-39-14-3-44-26-8-40-6-21-15-16-19-22 was the most optimal 24 mark ruler possible.


The RC5-64 project ended on July 14, 2002 when the announcement was made that the key 0x63DE7DC154F4D039 that produced the plaintext output "The unknown message is: Some things are better left unread" had been found.

CS-Cipher Challenge:

The [/csc/ CS-Cipher Challenge] was organized by CS Communications & Systems and was planned to last one year, through March 17, 2000. found the key to decypher the unknown plaintext on January 16, 2000, after testing more than 98% of the keyspace in under 2 months! This challenge was meant to demonstrate how weak a 56-bit key is against brute force attacks.


This project began on January 13th, 1999, at 9 AM PST. We successfully finished it after 22.5 hours with the help of EFF's Deep Crack custom DES cracker and achieved the $10K prize. For more information, feel free to peruse our DES-III headquarters.


Just like its predecessor, DES-II-2 was a timed contest. However, this time we were not able to find the key before the Electronic Frontier Foundation discovered the plaintext to be "It's time for those 128-, 192-, and 256-bit keys" through their use of custom hardware.


The DES II-1 challenge was a time-dependant contest from RSA Labs which began on 13-Jan-1998 and was completed on 24-Feb-1998 with the key 76 9E 8C D9 F2 2F 5D EA and produced the plaintext message "The unknown message is: Many hands make light work."


RC5-56 ended October 22, 1997 when the official announcement was made that the the key 0x532B744CC20999 presented us with the plaintext message "The unknown message is: It's time to move to a longer key length" was found.