Piecing together a secret past

This story fascinates me. Helen Dunmore drew my attention to it when I interviewed her recently. The E-Puzzler is a piece of machinery being used to "reconstitute" the shredded Stasi files: 45 million documents evidencing the East German secret police's activities prior to 1989, a time when it's estimated there was one police informer for every seven citizens.

"In some ways the E-puzzler works like a human doing a jigsaw, only much faster and without the benefit of a box-lid to show what the puzzle should look like. First, the fragments from each bag are smoothed out and fed into a large scanner: not just ordinary paper but carbon paper, photographs, microfilm, newsprint and folders. The unique characteristics of each piece — shape, colour, font, texture, handwriting, paper-type, edges and thickness — are stored digitally. Using an algorithm, the computer groups together similar fragments to reduce the “search space”, and then locates pieces that join up by matching the different characteristics. The task was made slightly easier by the fact that the Stasi rippers tended to bundle the scraps from sets of files into a single bag."

Link to the full article from The Times, 22 March 2010