Thanks for the fast replies :) > Scientifically? Unfortunately not. Loop-AES is only secure if it has > been set up in multi-key mode with encrypted swap. Yes, I already read this from the docs. If all these options are activated, there is no attack possible (at least not yet known)? I need the highest possible security, because the backup servers are not trustworthy. I also read some pages about a (very theoretical) attack of AES. Does somebody have benchmarks for AES128, AES256 and other ciphers like twofish etc? Are the performance differences between these ciphers even noticeable on a P4 3 GHz running database services and Samba? > OTOH, don't know about your setup... a different approach could be to > split up your large data collection in smaller chunks (directorywise, > f.e.) tar/bzip2 'em up and use gpg to encrypt the *.tar.bz2. > > Additionally you could use rar to create archives with recovery > information, this comes in handy if network traffic somehow caused > corrupted files. The big disadvantage with gpg is that even slightly > corrupted encrypted files can't be decrypted. Therefore I use the > 'protective layer' of rar archives. :) > > Then you could use rsync (over ssh) for backup. This method is quite > messy (setup, maintenance, ressources), but works. I thought about such a solution, too, but it simply doesnt work in my case. See, my servers hold hunderts of gigabyte of data. If just 1 bit is changed, gpg would create a different encryption stream from this on => the gpg file is not rsyncable, so that each day my entire data would have to be transferred. Creating a gpg archive for each directory or even for each file would still be too inefficient, because I have very large database files with a size of multiple gbs. They are really good rsyncable when not encrypted. The aim would be to add real strong encryption and to keep the efficiency of rsync. Another question: how does loop-aes react on bad blocks? - Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/
