Securely erasing tape media - How To?

[Anonymous]

Without access to a degausser, whats the best way to erase the contents of a tape securely, or what needs to be done to make it very difficult to retrieve tape contents.

There is the option in NetBackup for a Quick Erase and a Long Erase. The latter is out the question as it takes too long (SDLT320 tapes)

Any thoughts on the above options?
Is Quick Erase secure? And is it the same as 'mt -f /dev/tape1 erase' for example?

Using Unix I was also thinking of maybe using 'dd' to write blocks of null data at the front of the tape.
But how would I do this.

[Stumpr2]

Depends on what you call secure. For the US government the requirement is to destroy the tape! There are software programs available that will wtite 1's and 0's of alternating patterns to a tape. You could also simply do an OS level tar to the tape. One thing you do NOT want to depend on is expiring the tape because that is simply a catalog function and it does not alter the tape in any fashion. You may be able to simply do a bplabel command on the tape. If the tape never leaves the library and will only be available to a NetBackup environment then that should be OK as Netbackup will re-use the tape if it is placed into the scratch pool. Again, it pretty much depends on the level of security you need.

[Lance_Hoskins]

To re-emphasize what Bob said, without destroying the tape I don't think you can ever consider it secure to the point at which data cannot be taken off of it. Where there's a will, there's a way!

As far as the quick and long erase in NBU, the quick erase mearly erases the header information. Anyone with enough knowledge of what they're doing can easily get data off of that tape.

Again, all depends on how "secure" you want it...

[zippy]

degausser or fire fire

JD