Robot reconstructs millions of shredded Stasi documents

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Researchers in Germany have unveiled a massive computer-aided project to reconstruct millions of confidential files which were shredded by the East German secret police at the end of the Cold War. After the fall of the Berlin Wall in 1989, Stasi officers were ordered to destroy incriminating documents relating to the Stasi's operations. Many of these documents were burnt, but others were hurriedly shredded or torn into pieces. The West German police later recovered 16,000 sacks of paper, containing 600 million fragments from 45 million documents. Since 1995, a team has been piecing these fragments together by hand, but it is slow, painstaking work: in 12 years, only 320 sacks have been reconstructed and it is estimated that it would take hundreds of years to finish the task.

Help has recently appeared, however, in the form of Berlin's Fraunhofer Institute of Production Facilities and Construction Technology. The Institute has made its E-Puzzler software available to the German government at a cost of £4 million. The same software has also been used to help reconstruct smashed figures from China's Terracotta Army, and to recover evidence from shredded documents in fraud and tax evasion cases.

In the case of the Stasi documents, fragments are scanned and analysed for paper thickness and colour, typeface and fragment outline. This information is used to match similar pieces together until a complete digital reconstruction of a page can be achieved. The E-Puzzler machine can process 10,000 double-sided sheets of paper every hour, and it is expected to finish its task by 2013.

The machine that is putting together the Stasi's 600m-piece spy jigsaw -- Guardian Unlimited

Computer saves shredded Stasi files -- The Register

Berlin recovers Stasi secrets -- United Press International