Encrypted file systems
Some more thoughts on encrypted file system design criteria. A wish list: - Choice of secret key encryption algorithms (IDEA, 3DES, MDC, Blowfish) - Multiple architectures (MSDOS, Win31, Win95, WinNT, Unix, Mac) - High performance (hand optimised assembler for each architecture) - Compression - Ability to chain algorithms (IDEA and then 3DES for example) - Possible to have encrypted file systems on separate partitions, or - Encrypted file system located in a file in another file system (much like DOS stacker drives) this is an ease of use criteria -- I suspect re-partitioning drives would put off many potential users. - Ease of use. Graphical user interface for setup and administration functions, with a very simple set of configurations options displayed by default, with more advanced configuration options available in "expert" mode. - All directory and FAT information should be encrypted, so that it is not possible to discover even number of files, or percentage of disk used without the key - Facility for duress key, with the real data hidden in the unused space of the first encrypted drive. To increase the plausible deniability all unused blocks within a file system should be filled with garbage, so that it is not possible to tell if there is more data there. - File system steganographically hidden in files on another file system (encrypted or not). Support for a wide selection of file formats (Aiff, Wave, Midi, JPEG, GIF, RGB, MPEG). - Ability to use stegoed file system in files on an unencrypted file system, and boot from a floppy to access stegoed file system, with no other traces left on hard disk. Thought for the day: the main barrier for a Chinese dissident to using such software is that being caught with a boot floppy with the software for a stegoed drive would be dangerous. What would solve this would be if Microsoft, Apple, UNIX vendors, Slackware linux included this functionality (or this software itself as useful freeware included with the CD distribution) in their respective O/Ses as non-optional modules -- that is you get the software installed whether you want it or not. If everyone has the software, mere possesion of the software no longer is a problem. Throw in a few useful utilities, like a steganographic interface to anonymous remailers, the address of a few ftp/www by email services, and you have a system with interesting possibilities. To improve the national security of the US, the NSA should be dropping CDs with such software (much like war-time propoganda leaflets air dropped) on undemocratic countries with poor human rights records. Instead they expend their efforts on ITAR... Adam -- #!/bin/perl -sp0777i<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<j]dsj $/=unpack('H*',$_);$_=`echo 16dio\U$k"SK$/SM$n\EsN0p[lN*1 lK[d2%Sa2/d0$^Ixp"|dc`;s/\W//g;$_=pack('H*',/((..)*)$/)
On Jul 14, 12:48, Adam Back wrote:
Subject: Encrypted file systems - Encrypted file system located in a file in another file system (much like DOS stacker drives) this is an ease of use criteria -- I suspect re-partitioning drives would put off many potential users.
There are a couple of advantages to this sort of approach (i.e. having the encrypted filesystem live in file(s) on an ordinary filesystem) other than ease of use. 1. Backups are easy. One can use whatever backup software one normally uses. 2. The encrypted filesystem can actually live on a remote file server with data being encrypted/decrypted on the fly on the local host. (of course, you have to consider the security risks that you get from being on a network). -- Mark Henderson -- mch@squirrel.com, henderso@netcom.com, markh@wimsey.bc.ca ViaCrypt PGP Key Fingerprint: 21 F6 AF 2B 6A 8A 0B E1 A1 2A 2A 06 4A D5 92 46 unstrip for Solaris, Wimsey crypto archive, TECO, computer security links, change-sun-hostid, Sun NVRAM/hostid FAQ - http://www.squirrel.com/squirrel/
On Sun, 14 Jul 1996, Mark C. Henderson wrote:
> On Jul 14, 12:48, Adam Back wrote:
> > Subject: Encrypted file systems
> > - Encrypted file system located in a file in another file system
> > (much like DOS stacker drives) this is an ease of use criteria -- I
> > suspect re-partitioning drives would put off many potential users.
> There are a couple of advantages to this sort of approach (i.e.
> having the encrypted filesystem live in file(s) on an ordinary
> filesystem) other than ease of use.
> 1. Backups are easy. One can use whatever backup software one normally
> uses.
> 2. The encrypted filesystem can actually live on a remote file server
> with data being encrypted/decrypted on the fly on the local host. (of
> course, you have to consider the security risks that you get from
> being on a network).
An interesting thought:
One of the things that the entertainment electronics industry is pushing
is the "Set Top Box" that attaches to your idiotbox and allows you to
use the internet over either a POTS line, cable modem or whathave you. Problem
is, there is no local hard drive. No way to store sensative data (even a hot
list). With the encrypted filesystem stored on a remote machine, and using
something like SSH written in a Java like language (NOTE: Of necessity MUCH
more secure) to "Mount" the SFS over the network...
Something like this could make the author a decent amount of money. Makes
me wish I were a coderpunk.`
Petro, Christopher C.
petro@suba.com <prefered for any non-list stuff>
snow@smoke.suba.com
participants (3)
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Adam Back -
Mark C. Henderson -
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