Instead of cutting paper in long strips, they cut in both directions in miniscule pieces.

That's perhaps the funniest thing about all this. The whole crew is terribly inept.

There is more expensive equipment but not non-affordable. It depends on the desired level of security. Mine was about €400 when I bought it 2 years ago. It is cheaper now (+/- €250).

I have a document shredder that cuts both ways and reduces the paper to small confetti. In theory, reconstructing a document is possible but extremely complicated and expensive.

I do not need a more sophisticated device, it is only for confidentiality towards my clients.

I don't understand why Cohen didn't choose a device with a higher level of security. Especially since he was a partner in the firm that defends Cambridge analytic. There are high-performance devices that combine a high degree of safety with intensive use for less than 1000 €. It's not really prohibitive for such a firm...

One would think that someone who knew he/she was involved in criminal acts would spend the extra money for added security. There are two possibilities:

1. Cohen did not think he was committing any crimes (that is very difficult to believe)
2. He knew he was committing crimes but did not fear prosecution (I think this is probably more likely)

It is still mind boggling that someone in his position would not spring for the shredder that cut two ways! But you know, his boss likes to go cheap, too. Maybe that is something these criminal types have in common?

There is not a shredder on the market that can exceed the forensic science of today.

All they do is keep you safe from your average dumpster diving identity thief.

There was news a few months ago about scanning old books too fragile to open. Maybe something like that can "read" large burnt pieces of paper.

DoD command did with classified documents.

The really secure paperwork (that I certainly had no access to!) was shredded, then pulped, then dried out and incinerated, all on site.

Then again, we also had a secure library that had a man-trap entrance with armored doors, guarded by two very large, serious men armed with M4s and posted shoot-to-kill orders. The Department of Energy is definitely not as warm and fuzzy as Rick Perry thought it was

Can't remember where, but bleach and then incinerate would makes it damn hard

If a determined investigator has the resources, he or she can recreate copies of documents.

I am a scientist and i know this well. There is a size beyond which the problem is not solvable with existing computers. If you have millions of pieces, i.e nearly dust, there are two many possibilities for even a super computer to calculate within our lifetime. In physics and also in computer science we have myriad problems like that. Many body problems In physics, or problems that ends up being in the realm of chaos theory.
Now obviously, if it's big enough pieces of papers, the problem can be solved with a fast computer. Once you go below a certain size, it's just intractable.

Below a certain size it's not reconstructable
but the problem is not the number of combinations - it's signal-to-noise and uniqueness of piece size and shape.

Given modern clusters/cloud setups, IF each piece was actually unique, one could do the parallel computations - a coarse match on edge size and then do finer matches on smaller features.

I don't have domain expert knowledge in shredders (maybe you do?) but a few million combinations are easy to solve given modern computers and a bit of a smart algorithm.

If you have millions of pieces. It a n factorial problem. Any slight error will add up as well making it unsolvable. Loom up chaos theory and billiards. And as you.point out, there is also a loss of information since small enough pieces will have ink particles rubbed off them. On top of that, the edges of the pieces will essentially behave like fractal surfaces.
Again, if you have a relatively small number of pieces, it's indeed solvable but there are definitely shredders that are secure. It's used every day at the cia, fbi or even the doe where I work.

you mentioned, because the equipment is expensive. Even dust, at some level has shape and a form, a powerful enough system can figure that out. I am an engineer who is very familiar with high technology, I would not put anything beyond the capability of modern super computers built with large arrays of multi-core microprocessors and linked to imaging equipment that can discern shapes down to millimeter size or less. I have learned to never define what is capable in terms of past limitations, because the nature of technology is to defeat limitations and open up new capabilities.

One can not predict the movements of a billiard beyond a few collisions. Look up chaos theory. Essentially, the problem adds up to the point where a miniscule change in initial conditions yield a vastly different solution. It's the same issue in nuclear physics (my area of expertise) for the so-called many body problem for which the idea is to try to calculate the energy state (wave function) of a system with many atoms. They have the same issue in astrophysics. Computers nowadays are incredibly powerful, but even they have a limit. There are plenty of problems in physics that would take longer to solve than the life of the universe on modern supercomputers...

such as star formation or how galaxies interact (in astrophysics, the issue is more time than it is computing power, things like star formation and galaxy movements occur over millions or even billions of years, astrophysicists observing or trying to mathematically define those processes are working with a slice of information that is the rough equivalent of finding a particular grain of sand floating in a massive ocean).

Communication, literature or whatever follow certain rules, depending on the culture where the document was created. A powerful computer utilizing those rules can rule out a massive number of possibilities in mere hours, as define a limited set of best possibilities that can then be evaluated farther. So documents don't fit well in your application of chaos theory because hardest rules can be applied to reduce possibilities.

On wave functions (I am no expert, but I did have to study and understand the schrodinger equation while in college), in a multi-body environment, a particular wavefunction should have a set of possible values based upon physical parameters (like temperature, charge state of all the bodies, pressure, density of bodies, ect), there is always going to be some uncertainty at the end, but a defined set of possibilities can be calculated for each body.

I am currently working on a project where I have to react ions in confined ways to create materials that don't normally occur in nature. Creating stable materials that way is hard. The overall task is really hard, but at the end of the day, some hard and fast rules of chemistry and physic apply to what I am doing, as long asI understand that, I make progress.

Ils sont plus chers mais pas inabordables. Ca dépend du degré de sécurité voulu. Le mien a coûté environ 400 €. Je l'ai depuis 2 ans et maintenant on peut le trouver pour presque la moitié du prix.

J'ai un destructeur de documents qui coupe dans les 2 sens et réduit le papier en confettis. Ce n'est pas le plus sophistiqué, mais je n'ai pas besoin de plus, c'est juste pour assurer la confidentialité vis-à-vis de mes clients. Niveau de sécurité P-5, +/- une rame A4 par jour.

Il faut vraiment être un idiot de dimension inter-galactique pour ne pas avoir choisi un appareil moins basique ! Cohen pouvait largement se le permettre. On trouve des appareils ultra performants pour moins de 1000 €.

Ce n'est pas franchement impayable pour un cabinet comme celui de Cohen !

Cela dit, ça possible en théorie de reconstruire le document mais ça doit coûter un pont ! J'imagine qu'il existe des appareils tout à faits sécurisés mais je n'en vois pas l'intérêt pour le lambda qui veut juste se préserver au niveau privé.

together it's so fine. Although, I read someplace they dump it all on the floor, spread it out, take pictures and a computer reassembles it. ... so I guess it must/might be possible.

the computer picks up the changes when some of it gets flipped. However, apparently they used a simple vertical strip shredder which is the most simple of all to reconstruct, as I understand.

Then mate edges until the entire document is recreated. If you don't want it seen, if you are a criminal, burn it to ashes and stomp the ashes in high wind.

Vertical shredders. The cheapest ones that create vertical strips. I think this is what Cohen used, which is fairly easy to piece back together.

Cross-cut shredders: These cut documents both vertically and horizontally. Basically turns it into confetti. More expensive, but much harder to put the pages back together.

Then there is a super high end shredder that literally turns paper into tiny particles of dust that can't be reassembled. Pretty much the safest option to destroy paper documents short of burning them. But these shredders are industrial and very expensive. Not something you're going to find in your typical home or office.

I wouldn't be surprised if powerful computers could scan and reconstitute paper that was cross-cut. It would just have to be able to quickly try lots of combinations and see where lines matched up.

I had to use several in a previous career.

I'm not sure exactly how they work (someone here will explain, I'm sure), but I believe it has something to do with making several cross-cuts in addition to a vertical shred. Also, the width of the shred is extremely small.

The result is something that looks like micro-confetti, where the actual individual letters of text are cut multiple times, in both directions.

Turning them into dust or ash and spreading the ash around are safer options, but even companies that are trying to protect very valuable secrets seldom got to that extent (mostly because all a spy has to do is make an attractive person of the opposite sex available to people in the know, then fish out information that way). Most companies with valuable IP police key employees as much as they attempt to make documents unreadable.

I have not used said shredders since the early 90's. These were DoD mandated shredders to be used for the destruction of Top Secret documents. I'm sure it's an entirely different ballgame now considering how far technology has advanced since then.

because I know from experience that claim would be vastly untrue. But what I also know is that I would not put anything past a team of dedicated technologists and investigators, because in those situations, advancements once considered impossible happen, I have seen that with my own eyes and have even participated in a small amount of it.

The vaunted cross-cut shredders are not good enough any more. Scanner technology combined with reconstructive computer algorithms provides the ability to turn the tiny shreds of paper into a reasonable recreation of the original document.

The only way to truly get rid of paper is to burn it and stir the ashes. Even then, there might be some remnants!

. . . . . impossible as I can imagine. Imagine a very large garbage disposer that grinds paper in a water bath, reducing the paper to a fiber pulp. The water washes away almost any for of ink, including laser printing. The pulp is then pumped into a dewatering press which squeezes the water out, leaving a grayish mass of washed fiber with quite likely zero trace of print. The water is recirculated back to the "garbage disposer" to wash more paper and reduce it to fiber.

The system is tens of thousands of dollars for a small one.

They were developed as waste reduction devices but they were soon seen as a very effective document destruction device. Agencies of the government with three letter acronyms for names use them, for example.

And even then - burn, baby, burn.

They come in levels - for levels of security needed.

Buy better than you think you need.

ETA: Not that I have anything to hide.

The Walter & Jack 9000.

When the shredder bin gets about half full I add the contents to my compost pile. A few weeks and there's almost nothing left.

My recently deceased uncle spent quite a bit of time at the Teufelsberg listening post in Berlin during the cold war.
He once explained to me that they destroyed sensitive documents by first shredding then mixing with water to make a slurry. This post brought back the memory.

Before he died he began to reveal their capabilities and how they could monitor all East German communications. It was simply amazing considering the tech of the day.

https://en.m.wikipedia.org/wiki/Teufelsberg

This is the shredder in question:



There's a duct coming out the back of these machines that leads to a compactor in the other room. The pulp is misted with a small amount of water so it'll form a good stiff brick when it's squished together.

BTW, when was your uncle there? I was there from November 1986 to April 1992.

If I recall correctly, 1970 -76 He spent his entire career in signals intelligence beginning in Korea through retirement. There were times he would just disappear for over a year at a time. Would show up again and explain he was just "taking in the sights" and smile. We knew better than to ask.

If you don't want them read, burn them to ash and stop the hell out of the ashes. Modern technology make it possible for a determined investigator with resources to reconstruct a shredded document, regardless of how extensively it is shredded.

Shred a bunch of it and pack it into plastic bags (8 or 13 gallon trash bags are good). Then tie the bags shut. They make very good packing material when you move or need to ship fragile items.

it around.

So that's not a problem. The paper is incorporated with the other contents quickly.

They are built out of cement blocks with a layer of patio blocks for the floor.
In the spring we clean out one side and use all the good dirt at the bottom, piling what isn't composted into the other side and the next year use that side, reversing the process.

We let several Hmong families have large garden spaces and another couple took our space this year. At the end of the season, all the garden waste is piled in the composts also as well as our grass clippings all summer and the leaves in the fall. What leaves don't fit in the compost is spread directly on the garden spaces.

We had one 4x8 compost for a few years then expanded with another 4x8 section which makes the process work better because of the volume of garden waste and leaves at the end of the summer.

We just light all our sensitive papers, all twelve a month, and let them ash out in the sink, then wash it down the drain. I'm pretty sure that's TS/SCI compliant, let alone my bank statement..

If you don't break up the ash, there are chemicals you can use to recover the information on it.

We had two of them at Field Station Berlin. The finished product from one looks like dryer lint. These machines are so thorough in demolishing documents, we sold the shreddings to a local company that made it into insulation.

then this is just child's play. Criminals tend to live in the moment.

If it's a strip cut shredder then there's a chance that documents could be put back together. If it's a confetti cut shredder, then you're fucked.