Reassemble Shredded Paper
Just the other night, I was at home enjoying a night in. I popped the top off a beer and channel surfed until I found something I could get into. On Channel 4 – the movie Argo had just started. Chances are you will have probably seen it, but if not, it’s a Ben Affleck Movie about 6 American Embassy Workers in Tehran who go and hide out in the Canadian Embassy whilst the US Embassy is raided by Iranian Students (thugs).What makes this movie so amazing is that it’s an actual true story. But as you probably figured, this isn’t a blog about movie reviews. There was a specific scene in the movie that jumped out at me. It showed Iranian Students laying out all the shredded paper on the floor that they recovered from the CIA office within the US Embassy.
Putting Together The Pieces
In a previous blog, we discussed retrieving data from hard drives that were seemingly wiped, but was un-shredding paper really possible. I knew the process of reassembling shredded papers (through certain shredders) was indeed possible, but I wanted to explore further. We bought a cheap office shredder and shredded a single page of text. Within 10 minutes we had reconstructed the entire document. Wow – what else was possible? A wonderful article in ABC News led me to a competition that DARPA had setup in 2011 to un-shred?!
In October 2011, DARPA (Defense Advance Research Projects Agency) decided to run a competition for computer scientists. The competition had a prize of $50,000 for the team that could be the first to develop software that would visually piece together 5 documents that had been shredded by a paper shredder. An astonishing 9,000 teams applied for the Dapra Shredder Challenge, but 1 winner was crowned just 2 days before the end date of the challenge.
A San Francisco team made up of 3 computer programers won the prize in December 2011. The team called All Your Shreds Are Belong To U.S was made up of the friends Otavio Good, Luke Alonso and Keith Walker. Their winning algorithm was able to separate and piece together the 5 sheets of jumbled together, shredded paper, using a number of techniques such as marks on a page, fold marks and rips.
I found this challenge quite amazing, and soured from youtube a 4 year old video of someone who had in fact applied for the prize. He explains his process below:
So the question is, how safe are office shredders. Perhaps now after knowing this story, you can see how professional paper shredding services are needed. And remember, all this happened in 2011, we’re in 2016 now – how technology has moved a long way since.
I can see why some people would need an office paper shredder. For the odd document or single few sheets of paper, it’s convenient and it’s there. But it’s not effective. And as you can see from the above, reconstructing shredded sheets is no longer a think of the movies – it’s happening now. Be smart, be prudent and be sure to hire a professional shredding company to shred all of your confidential papers.