The RSA Secret-Key Challenge was a series of

cryptographic Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More gen ...

contests organised by

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

with the intent of helping to demonstrate the relative security of different

encryption algorithm In cryptography, encryption (more specifically, 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 information, known as plain ...

s. The challenge ran from 28 January 1997 until May 2007.

Contest details

For each contest, RSA had posted on its website a block of ciphertext and the random

initialization vector In cryptography, an initialization vector (IV) or starting variable is an input to a cryptographic primitive being used to provide the initial state. The IV is typically required to be random or pseudorandom, but sometimes an IV only needs to be un ...

used for encryption. To win, a contestant would have had to break the code by finding the original plaintext and the

cryptographic key A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm In mathematics and computer science, an algorithm () is a finite sequenc ...

that will generate the posted ciphertext from the plaintext. The challenge consisted of one DES contest and twelve contests based around the block cipher

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) ...

. Each of the RC5 contests is named after the variant of the

cipher used. The name ''RC5-w/r/b'' indicates that the cipher used ''w''-bit words, ''r'' rounds, and a key made up of ''b'' bytes. The contests are often referred to by the names of the corresponding distributed.net projects, for example RC5-32/12/9 is often known as RC5-72 due to the 72-bit key size. The first contest was DES Challenge III (and was also part of the

DES Challenges The DES Challenges were a series of brute force attack contests created by RSA Security to highlight the lack of security provided by the Data Encryption Standard. The Contests The first challenge began in 1997 and was solved in 96 days by the ...

) and was completed in 22 hours 15 minutes by distributed.net and the EFF's

Deep Crack 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 decr ...

machine. In May 2007 RSA Laboratories announced the termination of the challenge, stating that they would not disclose the solutions to the remaining contents, and nor would they confirm or reward prize money for future solutions. On 8 September 2008

distributed.net 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. ...

announced that they would fund a prize of $4000 for the RC5-32/12/9 contest.

Distributed.net

The contests are associated with the

group, which had actively participated in the challenge by making use of

distributed computing Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different networked computers. The components of a distributed system commu ...

to perform a

brute force attack In cryptography, a brute-force attack or exhaustive key search is a cryptanalytic attack that consists of an attacker submitting many possible Key (cryptography), keys or passwords with the hope of eventually guessing correctly. This strategy can ...

. RC5-32/12/7 was completed on 19 October 1997, with distributed.net finding the winning key in 250 days and winning the US$10,000 prize. The recovered plaintext was: ''The unknown message is: It's time to move to a longer key length''. RC5-32/12/8 also carried a US$10,000 prize and was completed by distributed.net on 14 July 2002. It took the group 1,757 days to locate the key, revealing the plaintext: ''The unknown message is: Some things are better left unread''. There were eight contests that had not yet been solved, RC5/32/12/9 through RC5/32/12/16, each of which was a US$10,000 prize. Distributed.net is working on RC5-32/12/9 and were at 12.298% as of July 13 2024 (7.559% as of March 22 2021, 6.700% as of 20 June 2020, 5.329% as of 18 September 2018, 4.356% as of 7 January 2017).{{Cite web, title=stats.distributed.net - RC5-72 Overall Project Stats, url=http://stats.distributed.net/projects.php?project_id=8, access-date=2020-06-21, website=stats.distributed.net

References

External links

Official contest page on the RSA websiteEncrypted messages from contestUnofficial status page on Distributed.netDistributed.net's RC5-72 Project Statistics
Cryptography contests Recurring events established in 1997 Recurring events disestablished in 2007

Contest details

Distributed.net

See also

References

External links