[sllug-members]: Encrypted backup tapes

[M. Alton jensen]

> My experience with a small tar file of text files files was that the
> size of the tar file gzipped and then encrypted was the same size as the
> tarfile just encrypted. At the time it made sense to me because the
> encryption routine needs to get the highest entropy possible, and
> encrypting plain text starts with low entropy.
> 
> Does this hold true for larger files?
> 
> Andrew

I'm not sure if this is distro specific, but the defaults for gnupg on
my desktop(SuSE) include compressing the item being encrypted.  I ran a
simple test with a text file to confirm this and here are the results.

> du -sk test.txt*
328     test.txt
40      test.txt.gpg
40      test.txt.gz

I'm running into some problems when I try to encrypt my backups and send
them directly to the tape device.  Sending the output to a file works
fine.  I'm going to do a little more research and experimenting and will
post more info on what I find to the list later.

-Alt