German researchers have announced that they were launching an attempt to reassemble millions of shredded East German secret police files using complicated computerized algorithms. Some 16,250 sacks containing pieces of 45 million shredded documents were found and confiscated after the Berlin Wall was torn down. Reconstruction work began by hand 12 years ago but 24 people have only been able to reassemble the contents of only 323 sacks. The project was halted due to the slow progress. Putting the machine-shredded documents together requires analysis of the script on the surface of the fragments. The institute has already had success putting together similarly destroyed documents for Germany’s tax authorities

Paper should not only be shredded but then the shreds should be pulped into new paper. This is the process used by all shredding services.