DARPA Shredder Challenge Rules


The Defense Advanced Research Projects Agency (DARPA) is conducting the DARPA Shredder Challenge (henceforth referenced as the "Challenge"), a prize-based competition that seeks to identify and assess potential capabilities that could be used by our warfighters operating in war zones, but might also create vulnerabilities to sensitive information that is protected through our own shredding practices throughout the U.S. national security community.


The Challenge begins at 12:00PM EDT on October 27, 2011 and ends at 11:59PM EST on December 4, 2011.

The Challenge consists of five individual puzzles, each composed of one or more single-sided, hand-written documents. The pages for each puzzle have been shredded separately; however, the shredded pages for each individual puzzle have been mixed together. All documents were shredded on newly purchased, commercial grade shredders. Some shredded puzzle pieces may have some slightly blurred writing due to the transfer of oil from the shredding blades. Additionally, each puzzle may contain a small number of additional pieces or a few missing pieces, precluding a 100% reconstructed document. After shredding, puzzle pieces have been collected, arrayed top-side-up, and scanned at 400 dots-per-inch using one or more TIF 6.0 images (lossless compression). To score points, participants must download the images of the shredded documents from the Challenge website, reconstruct the documents, solve the puzzles, and submit the correct answers to the Challenge website before the December 4, 2011 (11:59PM EST) deadline.

Challenge results will be posted on the Challenge website during the week of December 5, 2011. In the event a participant correctly solves all the puzzles prior to the deadline, the Challenge will be terminated and DARPA will announce the winner immediately.

Participation and Eligibility

Participation in the Challenge is open to individuals and teams of all ages except as noted below. Entries may only be submitted by a registered participant, who must be a permanent resident or citizen of the United States and 18 years of age or older at the time of registration. Proof of residency and age will be required from the winner before the prize will be awarded.

Employees of the U.S. Government, including spouses and dependents for tax year 2011, are not eligible to participate. DARPA employees and DARPA support contractors and their immediate families are not eligible to participate.

All Challenge participants who desire to submit solutions or access the discussion forum must register through the Challenge website (archive.darpa.mil/shredderchallenge) before 5:00 PM EST on November 28, 2011. Each participant is permitted only one registration. Registrations may be withdrawn at any time by emailing the Challenge mailbox (shredderchallenge@darpa.mil). Registration will be acknowledged by DARPA via email within one business day.

Questions regarding eligibility and participation should be directed to the Challenge mailbox at shredderchallenge@darpa.mil.


All participants registered or otherwise, may download the puzzles from the "Download Puzzles" tab on the Challenge website at the start of the competition. The puzzles will be available in a ZIP format that includes the associated TIF image(s) and a TXT file. The TXT file contains amplifying instructions as well as the associated puzzle-specific question(s) that must be answered in order to score points. The TXT file also includes a set of additional questions that DARPA requests participants answer in order to conduct analysis of the various reconstruction methods used by the participants.

Registered participants may submit their solution for each puzzle via the "Submit Solutions" tab on the Challenge website. Registered participants are allowed to submit solutions for each puzzle as many times as they desire, but only the answers contained in their latest submission will receive a score. For puzzles in which multiple answers are required, all answers must be submitted in the same upload. Puzzle solutions may be submitted individually, in any order, and at any time prior to the deadline. There is no requirement to submit solutions for all five puzzles. There is no requirement to reconstruct documents completely, only reconstructed sufficiently to answer the required question(s).

Submitted solutions must be in ZIP file format, no larger than 20MB, and contain the following: (1) Image(s) of the reconstructed document(s) in a common image format (TIF, JPG, etc); and (2) TXT file containing answers to the mandatory and additional questions.

All submitted files must be named using to the following convention: "puzzleX.ext" (e.g., puzzle1.zip, puzzle1.jpg, puzzle1.txt). The website will automatically tag uploaded files with the registered participant's identification and time of submission. The website will display confirmation of a successful file upload.

Problems with downloading or uploading files should be directed to the Challenge mailbox at shredderchallenge@darpa.mil.


Solutions to the Challenge will be accepted from 12:00 PM EDT, October 27, 2011 until the Challenge deadline at 11:59 PM EST on December 4, 2011. The DARPA Shredder Challenge project team will score all submissions. Late or incomplete submissions will not receive any points.

Points are awarded for providing the correct answers to the mandatory questions contained in the TXT file associated with each puzzle. For puzzles with multiple questions, it is possible to earn partial credit for each correct answer provided. Points will not be deducted for incorrect answers.

Points available per puzzle are based upon the following rubric:
Puzzle 1:   2 points
Puzzle 2:   4 points
Puzzle 3:   8 points (partial credit available)
Puzzle 4:   12 points (partial credit available)
Puzzle 5:   24 points (partial credit available)
Total:    50 points


The Challenge will award one cash prize of up to $50,000. The overall winner will be the eligible, registered participant that achieved the highest point total by the Challenge deadline. In the event of a tie, the registered participant with the earliest time stamp of his/her last submission will be the winner.

The cash prize amount awarded will be based upon the total number of points achieved by the overall winning participant. $1,000 will be awarded for each point scored up to $50,000 for a perfect score. There is no minimum point total required to receive the award.

The prize money will be transmitted by electronic funds transfer to the bank account of the individual determined by DARPA to be the overall winner. If the overall winner is the leader or member of a team of participants, it is the responsibility of the overall winner, not DARPA, to determine the subsequent division of any prize money.

Tax treatment of prizes will be handled in accordance with U.S. Internal Revenue Service guidelines. The recipient must provide an appropriate U.S. taxpayer identification number (e.g., social security number, employer identification number, etc). The recipient should consult a tax advisor to ensure that winnings are handled properly and reported accurately for tax purposes.

If DARPA is unable to contact the winning participant within 72 hours after the announcement of the winner, DARPA may award the prize to the runner-up.

Additional Information

The Challenge is authorized under 10 U.S.C. § 2374a, which authorizes the Secretary of Defense to award prizes in recognition of outstanding achievements in basic, advanced, and applied research, technology development, and prototype development that have the potential for application to the performance of military missions of the Department of Defense.

The rules apply to all participants in the DARPA Shredder Challenge and may be changed without prior notice. Participants should monitor the Challenge website (archive.darpa.mil/shredderchallenge) for the latest information.

Registration information collected by DARPA will be used solely for the purpose of administering the event. Registration information will not be distributed to any parties outside of DARPA nor released for any other purpose except as noted in this document.

Individual participants' display name may be listed on the Challenge website to enable the event to be tracked by interested members of the public. The name and photographs of the winner may be posted on the DARPA website and released to the media.

DARPA may contact registered participants to discuss the means and methods used in solving the Challenge. DARPA will retain no record of individual entries after the event is complete, but may compute and release to the public aggregate data and statistics from the submitted solutions.

Nothing in these rules, to include information on the Challenge website and communications by DARPA officials, may be interpreted as authorizing the incurrence of any costs or modifying the statement of work or authorizing work outside the terms and conditions of any existing agreements or contracts with DARPA.

DARPA claims no rights to intellectual property developed as a result of participation in the Challenge.

DARPA reserves the right to disqualify a participant whose actions are deemed to violate the spirit of the competition for any reason, including but not limited to, the violation of laws or regulations in the course of participation in the Challenge. DARPA does not authorize or consent to participants infringing on any U.S. patent or copyright while participating in the Challenge.

DARPA may cancel or modify the Challenge without notice.

The Director, DARPA is the final decision authority for all matters concerning the Challenge.

By registering and/or participating in the Challenge, participants agree to follow these Shredder Challenge Rules and to hold harmless and release the U.S. Government from any and all liability and costs arising from the participant's participation in the Challenge.

The appearance and reference to any person, name, place, film, artwork or any other images that are used in connection with the Challenge does not constitute or imply endorsement by the Department of Defense, U.S. Government or DARPA.

Questions regarding the rules, privacy policy, or other aspects of the Challenge may be directed to shredderchallenge@darpa.mil.