Backing up encrypted files

  • Thread starter Thread starter Kevin D. Quitt
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Kevin D. Quitt

Is it safe to assume that an encrypted file will be backed up in its
encrypted form, or does it depend on the backup program? Where can I find
out the TRUTH (tm) about encrypted files? Thanks in advance.
 
The "truth" about EFS (everything you ever wanted to know and probably alot
that you could've lived happily without knowing):

http://www.msdn.microsoft.com/libra...ecure/html/WinNETSrvr-EncryptedFileSystem.asp

The built-in NTBackup utility will leave an encrypted file in its encrypted
state when it is backed up. While it's impossible to answer definitively
for every. single. backup product on the market, most backup software
operates at a "byte-copy" level, where it copies stuff to tape/disk one byte
at a time without knowing (or caring) about the semantics of what's
contained within the file.

All of the "biggies" in backup software (Veritas, Legato, etc.) will back up
encrypted files in their encrypted form, and (IMHO) you shouldn't be using
one that -doesn't-, if there's actually one out there.
 
Right.
If the software vendor doesn't make any statements about maintaining EFS
encryption, the only way to tell is to test it. If the app does not call
the *EncryptedFileRaw APIs, the backed-up media will show you plaintext,
assuming the backup worked at all. If the app is EFS-aware, the backup will
look like encrypted gobbeldy-gook.
 
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