The world’s biggest jigsaw puzzle may have to be solved by hand, as technology struggles to piece together millions of Stasi files ripped to shreds in the dying days of the East German regime.

The government-funded Stasi records agency confirmed this week that it had had to halt an €8m (£7m) project to digitally reassemble the contents of 23 bags stuffed with torn-up documents detailing the activity of the secret police, because the scanning hardware it was using was not advanced enough.

Over the 40-year existence of communist East Germany, the state security ministry built one of the most tightly knit surveillance states in recent history. The Stasi, short for the Ministry for State Security, created a vast web of full-time agents and part-time snoops, with some historians calculating that there was one informant per 6.5 citizens.

After German reunification in 1990 an archive was set up to allow the system’s victims to access their records, but not before stacks of paperwork were shredded or ripped up by hand to cover up the regime’s activity.

While there are no official figures on the volume of destroyed records, researchers estimate that 10-40% of the archive’s contents may be lost to history.

Since the early 1990s workers employed by the agency have managed to piece together more than 1.5m pages of destroyed files by hand, shedding light on East Germany’s use of doping in sports, links between the Stasi and West Germany’s Red Army Faction terrorist group, and the persecution of writers critical of the regime.

The reassembled files brought to light the story of a young Austrian theology student who shopped several fellow students to the Stasi after they had confided in him their plan to escape across to the west. As a reward, the informant was handed a professorship at the University of Jena.

Until 2015, the Stasi records agency outsourced some of the manual puzzling work to the federal refugee agency in Bavaria.

But workers have struggled with files that were torn up more than four times. “Once you have nine snippets per A4 sheet of paper, the human brain really can’t keep up,” said Dagmar Hovestädt, the spokesperson for the Stasi records agency.



A so-called ePuzzler, working with an algorithm developed by the Fraunhofer Institute and costing about €8m of federal funds, has managed to digitally reassemble about 91,000 pages since 2013. However, it has recently run into trouble.

A member of the Stasi Museum shows folders with records gathered by an informer for the secret police. Photograph: Felipe Trueba/EPA

For the last two years, the Stasi records agency has been waiting for engineers to develop more advanced hardware that can scan in smaller snippets, some of which are only the size of a fingernail.



The ePuzzler works by matching up types of paper stock, typewriter fonts, or the outline of the torn-up page. It has struggled with handwritten files that were folded before being torn, leaving several snippets with near-identical outlines.

The ePuzzler has also required human assistance to feed in paper snippets and check over the completed jigsaw puzzle, further slowing down the process.

“We currently don’t have a scanner that we can work with,” said Hovestädt, adding that her agency was hopeful that technological progress would allow the archive to resume reassembling destroyed records this year.

The Stasi records agency said its attempt to virtually piece together the history of a surveillance state was without a precedent in the world. “We are dealing with a research project that requires us to develop a technology entirely from scratch.”

In the meantime, a small team of manual puzzlers continue their work of matching up more crudely ripped files by hand.