DESCHALL, short for DES Challenge, was the first group to publicly break a message which used the

Data Encryption Standard The Data Encryption Standard (DES ) is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cryp ...

(DES), becoming the $10,000 winner of the first of the set of

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 ...

proposed by

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, ...

in 1997. It was established by a group of computer scientists led by Rocke Verser assisted by Justin Dolske and Matt Curtin and involved thousands of volunteers who ran software in the background on their own machines, connected by the

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

. They announced their success on June 18, only 96 days after the challenge was announced on January 28.

Background

To search the 72

quadrillion Depending on context (e.g. language, culture, region), some large numbers have names that allow for describing large quantities in a textual form; not mathematical. For very large values, the text is generally shorter than a decimal numeric repres ...

possible keys of a 56-bit DES key using conventional computers was considered impractical even in the 1990s. Rocke Verser already had an efficient algorithm that ran on a standard PC and had the idea of involving the spare time on hundreds of other such machines that were connected to the internet. So they set up a

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

on a 486-based PS/2 PC with 56MB of memory and announced the project via

Usenet Usenet (), a portmanteau of User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose UUCP, Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Elli ...

towards the end of March. Client software was rapidly written for a large variety of home machines and eventually some more powerful 64 bit systems. There were two other main contenders: SoINET (a Swedish group), and a group at

Silicon Graphics Silicon Graphics, Inc. (stylized as SiliconGraphics before 1999, later rebranded SGI, historically known as Silicon Graphics Computer Systems or SGCS) was an American high-performance computing manufacturer, producing computer hardware and soft ...

, a manufacturer of high-performance computers, which was in the lead until late in the day. Other groups using

supercomputer A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...

s withdrew after

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 on their networks.

The Project

With the software that was used, a single 200 MHz Pentium system was able to test approximately 1 million keys/second if it was doing nothing else. At this rate it would take around 2,285 years to search the entire key-space. The number of computers being used rose rapidly and in the end, a total of 78,000 different

IP address An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...

es had been recorded, with a maximum of 14,000 unique hosts in a 24-hour period. By the time the key was found, they had searched about a quarter of the key-space and were searching about 7 billion keys per second, but the number of participants was still increasing rapidly. The solution was:


Strong cryptography makes the world a safer place.

The owner of the computer that found the solution was awarded $4,000 of the prize, with the rest going to the originator of the project. The conclusion of the paper describing the project was "We have demonstrated that a brute-force search of DES keyspace is not only possible, but is also becoming practical for even modestly funded groups. RSA's prize for the find was US$10,000; it is safe to say that DES is inadequate for protecting data of any greater value."

Footnotes

References

External links

Archive of project material
{{Webarchive, url=https://web.archive.org/web/20100325222525/http://www.interhack.net/projects/deschall/ , date=2010-03-25

Cryptography contests Data Encryption Standard

Background

The Project

See also

Footnotes

References

External links