data encryption - was Re: [plug] protecting a tar file

[Denis Brown]

On the ways of preventing the exposure of the contents of a tar file, if it 
fell into the wrong hands...

At 07:04 1/07/2004 +0800, William Kenworthy wrote:
>zip -e the tar file.  zip has what is considered weak encryption but is
>simple to use.  There seem to be a number of other similar utilities
>that either compress and encrypt or just encrypt the file.

I was hoping to get away from file modification (eg. using zip) on the 
basis that a one-bit error may be fatal to the whole thing.   But then that 
also applies to my acceptance of GPG, doesn't it :-)

>or something like:
>tar -zcvf - stuff|openssl des3 -salt -k secretpassword | dd
>of=stuff.des3
>and
>dd if=stuff.des3 |openssl des3 -d -k secretpassword|tar zxf -

Thanks for the tips!   Hopefully useful to others, as well.

>or create a largish loopback container formated with stegfs on top of
>ext2 and put the tar into that.  That should stump a script kiddie!
>Played with this when I was using ext2 and it does work.

Stegfs, eh?   "StegFS - A Steganographic File System for Linux"   I'd not 
heard of that before.   More reading to do but this looks very interesting 
especially to those of us in the medical / human-data-sensitive 
fields.   Reference url:  http://www.mcdonald.org.uk/StegFS/   They seem to 
claim it is not for 2.4 kernels.

Cheers,
Denis