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rblampain 05-18-2007 08:41 AM

encryption & disk usage
 
I'd like to find out how normal files translate in term of disk space used after encryption in a partition or disk encryption scenario.

For example, if I have many small files of 512 bytes or 1024 bytes, how much disk space will they take within an encrypted partition or disk.?

Thank you for your help.

MoMule 05-18-2007 11:05 AM

I don't know the specifics you are looking for, but I have read that when using encryption algorithms on files you don't need to compress those same files (either before or after encryption) as the two tasks create roughly the same file sizes due to the mathematical similarities between compression and encryption.

If this is true:

Test this out by creating a small file. First encrypt a copy of it and use ls -lha to see the size. Then compress another copy of the original file and again use ls -lha to check the size. Compare the two file sizes. If they are roughly the same, then you can estimate what a folder full of small files compressed would be in size once the same folder is encrypted...

I believe that if the above is true then it should hold true for files being placed on an already encrypted disk or folder.

Deion "Mule" Christopher

R_Hellvis 05-18-2007 01:35 PM

There will be some overhead using any type of encryption (if the file isn't compressed before encryption. However, the file will only get a tiny bit larger depending on the algorithm used.

rblampain 05-19-2007 12:16 AM

Thank you very much for the answers.


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