Governments, businesses, and individuals rely on paper shredders to provide security when they want to keep their important information hidden. For example, security of company records is among the top five critical issues according to executives from 300 companies. However, paper shredders, particularly less secure strip shredders, have been defeated by various techniques. Here are four reasons to consider high security paper shredders:
Security levels for paper shredders range from level 1 shredders (the least secure) to level 6 shredders (the most secure). The level of the shredder is largely defined by the size of the shreds. Level 1, 2, and 3 shredding consist primarily of strip shredders, although a cross-cut shredder may fall within level 2 or 3, depending on the size of the final shred. Level 4 and 5 shredding use cross-cut shredders that leave shreds anywhere from about 1" x 1/4" to 3/8" x 1/10". Level 6 shredding leaves shreds less than 1/5" x 1/10" and is the only level of shredding acceptable under the U.S. National Security Agency's specifications for documents classified as top secret.
For any thieves or fraudsters, hand reconstruction of these shreds relies on human eyes and brains to recognize patterns in the shreds, such as the paper stock and folds, to reassemble shredded documents like jigsaw puzzles. There are famous examples of hand reconstruction. Documents shredded before the American embassy in Iran was taken over by Iranian students were reconstructed by hand and published by the Iranian government to embarrass the U.S. government. And in 1977, reporters from the Washington Post used hand reconstruction to reassemble documents recording bribes from a South Korean businessman to members of Congress. Smaller shreds, such as those produced by level 6 shredders, tend to defeat hand reconstruction by obliterating the patterns used to gather related shreds.
Computer algorithms have been created to aid in the reassembly of shredded documents. These computer algorithms examine shred characteristics, such as the paper color, shape, and printing or writing, that are stored in a database and attempt to match those shreds with other shreds in the database. This is essentially an automated version of hand reconstruction that relies on a computer's ability to "remember" more shreds and search more quickly for matching shreds.
Computer algorithms have likewise been used in some famous examples of reassembly. In Germany, a computer program has aided in the reconstruction of documents shredded before the fall of Communism by the East German secret police, the Stasi. In 2011, the Defense Advance Research Projects Agency (or DARPA) held a contest to reassemble five shredded documents from mixed up shreds. The winning team developed a computer program that used clues, such as markings, folds, and rips, to piece together the documents from the shreds.
In a more recent example, documents recovered from Michael Cohen's cross-cut shredder were reassembled by the FBI for use in a criminal case against him. While the FBI did not disclose how it reconstructed the documents, one may assume that the FBI used a combination of computer algorithms and hand reconstruction. Because current computer algorithms use the same technique as hand reconstruction, albeit in automated form, level 6 shredders can be used to defeat computer algorithms.
Crowdsourcing and distributed computing have been used for many purposes, such as sifting through large data sets for the Search for Extra-Terrestrial Intelligence (or SETI). Crowdsourcing and distributed computing rely on the same principle as inviting friends to help with a jigsaw puzzle. More brains or computers means more processing and quicker solutions.
While no examples of crowdsourced or distributed computing solutions for reassembling shredded documents exist, one of the proposed solutions for the DARPA challenge used a crowdsourced approach. In the approach, 3,500 people participated in hand reconstruction via the Internet, with the team relying on the sheer number of participants to create a viable solution. A distributed computing approach works the same way, but relies on multiple computers rather than multiple humans to reassemble the document. Again, because crowdsourcing and distributed computing use the same piece by piece examination of hand reconstruction, crowdsourcing and distributed computing can be defeated by level 6 shredders that obliterate the patterns in the shreds.
If you're in need of a level 6 shredder, rely on Capital Shredder Corp to meet your security concerns.