[Cryptography] Magnetic media destruction question

[Jerry Leichter]

> But how to do physical destruction? I suppose grind them up into little pieces. Isn't there a virtuous cycle here? Extra small naturally means considerable heating, which has its own destructive value.
> 
> There must be existing industrial equipment that can easily cut electronics into barely identifiable fine gravel, and different industrial equipment that can turn such gravel into a powder. Good enough for me. Would actually be kind of fun to be put on the task of figuring it out. There is certainly mining equipment that could do it, but it might all be on too large a scale. Maybe materials science labs have equipment on a more suited scale.
To the best of my recollection, at the time they used a press which drove a spike through the casing and the platters.  Yes, you can imagine technology that _might_ recover data from a drive treated like that, but it would be fantastically expensive - likely expensive beyond any value that the recovered data might have.

> That's a question: How much storage equipment does a typical data warehouse site need to dispose of in a week?
Well, you need only estimate the number of drives in the data center and their average lifetimes.  I'd guess you come out to a few tens a day at most.  Of course, there may be times when you're decommissioning large amounts of equipment, at which point you might bring in specialized machinery.  A standard shipping container can hold a lot of heavy equipment.

> And now that unique identifier seems particularly important—too easy to fail to remove some storage component, but if the purpose isn't to "remove" but to "recover" then any missing components means keep disassembling, until they are all accounted for.
When you decide that drive X will be decommissioned, you log that.  When you actually destroy it, you log _that_.  If something stays in the "being decommissioned" state for too long, you know something has gone wrong - e.g., X fell off the cart carrying it to the decommissioning station and slid under some nearby server.  This is considered a serious situation and you go search until you find the drive.  If you can't, you consider that a security incident and all kinds of things that are not pleasant for those working in the data center start happening.
                                                        -- Jerry