Disposing of old media

Discovering boxes of old backup tapes and hard drives when a client finally got around to cleaning out their PC graveyard and a press release pitching an NSA certified CD declassifier have me thinking about the process of media disposal. While I've always found a little thermite to be effective I understand that violent exothermic reactions aren't everyone's cup of tea. So how should you dispose of old tapes and disks?

Howard Marks

July 16, 2009

3 Min Read
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Discovering boxes of old backup tapes and hard drives when aclient finally got around to cleaning out their PC graveyard and a pressrelease pitching an NSA certified CD declassifier have me thinking about theprocess of media disposal.  While I'vealways found a little thermite to be effective I understand that violentexothermic reactions aren't everyone's cup of tea.  So how should you dispose of old tapes anddisks?

In the old days you could just throw them in the dumpster.Today that would put you on the wrong side of state laws that require embarrassing,and expensive, disclosures when personally identifiable information like socialsecurity numbers are lost or hacked. Hopefully the pitiful, if frequentlyentertaining, stories of tapes full of medical records stolen along with thecourier's car have convinced you all to encrypt all your tapes.

Unless you're worried about the NSA or Mossad spending yottaflopsto decrypt your old tapes and figure out that you're selling antimissilesecrets to Hamas you can safely throw encrypted tapes in the dumpster. This ofcourse assumes you've avoided the stupidity of writing the encryption key onthe tape labels (Yes I've seen it).

Working ATA and SATA hard disks of recent (post 2001)vintage have an embedded secure erase command that effectively locks drivesuntil the data overwrite completes even if the drive is powered off in themiddle of the process.  As a result youcan use the freeware secure erase program from UCSD's Center for MagneticRecording Research http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtmlto clear drives in a couple of minutes .The paranoid among you are saying "What about the track edgedata, can't you read that with an electron microscope? What about DoD 2550? Don'twe need to write 32 passes of different data?"

Let me be short with these:

  • The authors of the electron microscope article years agosay increased density and more complex data encoding makes the techniqueimpractical with today's drives

  • DoD 2550 is a 1996 spec and drives don't work the way itrequires them to as todays encoding makes writing all 0s impossible.

  • Remapped sectors aren't overwritten regardless of how manypasses.

Most significantly unless you're KNOWN to be throwing outmedia with data worth megabucks spending thousands to recover your data isn'tworth the criminal's time.  If someonediving your dumpster has a clean room and is willing to use it I recommendthermite.  This YouTube videodemonstrates the method. http://www.youtube.com/watch?v=AmywYdK8uCY

but a flowerpot works better than the soda can used in the video.

For optical disks there's the shredder.  My personal favorite Fellowes C-320 cutspaper and CDs into 5/32"x1/8" shreds, mix in a few Bay City Rollers CDs withyour valuable data just to give the guys doing reassembly a hard time.  Of course that's not good enough for some soI got the press release c for a product that can best be described asoverkill.  Today's example is Proton DataSecurity's 1250 CD/DVD Declassifier.  Asthe release says:

"Thecommercial and government security market requires a device to automaticallyensure that sensitive PII (Personal Identifiable Information), files,intellectual property, training materials and sensitive government data isdestroyed." Said John Lobo, Proton CEO. "The 1250A provides a high-productivity,economical solution to this requirement. The 1250A is the ultimate declassifierfor safe guarding optical media against data breaches and data loss."So it's even better than mixing in old AOL disks.
Tapes can also be shredded, but the shredder looks more likea wood chipper, and services will come to your site with a truck mounted shredder.
Disks and tapes can also be degaussed but not with the RadioShack bulk eraser you used on cassettes in college.  The bit densities of today's media requirePOWERFUL magnetic fields and therefore expensive erasers.
The one method I can't approve of is shipping media to adisposal service.  After all USPS can losethe box in transit creating the breach you were trying to prevent in the firstplace.
Comments, even snide ones, welcome.

About the Author(s)

Howard Marks

Network Computing Blogger

Howard Marks</strong>&nbsp;is founder and chief scientist at Deepstorage LLC, a storage consultancy and independent test lab based in Santa Fe, N.M. and concentrating on storage and data center networking. In more than 25 years of consulting, Marks has designed and implemented storage systems, networks, management systems and Internet strategies at organizations including American Express, J.P. Morgan, Borden Foods, U.S. Tobacco, BBDO Worldwide, Foxwoods Resort Casino and the State University of New York at Purchase. The testing at DeepStorage Labs is informed by that real world experience.</p><p>He has been a frequent contributor to <em>Network Computing</em>&nbsp;and&nbsp;<em>InformationWeek</em>&nbsp;since 1999 and a speaker at industry conferences including Comnet, PC Expo, Interop and Microsoft's TechEd since 1990. He is the author of&nbsp;<em>Networking Windows</em>&nbsp;and co-author of&nbsp;<em>Windows NT Unleashed</em>&nbsp;(Sams).</p><p>He is co-host, with Ray Lucchesi of the monthly Greybeards on Storage podcast where the voices of experience discuss the latest issues in the storage world with industry leaders.&nbsp; You can find the podcast at: http://www.deepstorage.net/NEW/GBoS

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