POV-Ray : Newsgroups : povray.off-topic : Defrag-proof files : Re: Defrag-proof files Server Time
5 Sep 2024 15:22:34 EDT (-0400)
  Re: Defrag-proof files  
From: Darren New
Date: 21 Jun 2009 01:24:17
Message: <4a3dc401$1@news.povray.org>
Darren New wrote:
> It went away after I deleted the files that used to be encrypted but no 
> longer are encrypted. Very odd.

I see. When you encrypt a file, it needs a place to store the symetric key 
used to encrypt the file, along with the public keys used to encrypt it. 
There has to be a way, for example, to add an escrow key. When you decrypt 
the file, Windows apparently keeps around the keys that were used to encrypt 
it, for some reason (that reason possibly being "a bug"). The problem with 
defragging them is not that you can't move the file, but that the API works 
by you passing a file handle to the file to be defragged, and for obvious 
reasons you can't open the fork of the file that holds the encryption keys 
for the encrypted file. I.e., security prevents you from opening the file in 
  a mode that would let you defrag it.

Copying the affected files to a new name and then deleting the old ones 
cleans up the problem. "cipher /u" apparently doesn't, but will let you see 
which files it thinks have keys associated, and if they aren't encrypted, 
you know which files might be problematic.

So I don't think it was "mydefrag" that moved the files, but rather that 
something cleaned off the encryption keys from files that used to be 
encrypted but aren't any longer. I bet compressing the files (and then maybe 
decompressing them if you need to) would achieve the same result, tho.

</ramble_babble>

-- 
   Darren New, San Diego CA, USA (PST)
   Insanity is a small city on the western
   border of the State of Mind.


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