From: edgar@spectrx.sbay.org (Edgar W. Swank)
Date: Tue, 3 May 94 02:16:56 PDT
To: cypherpunks@toad.com
Subject: Secure Drive is now obsolete NOT
Message-ID: <N0RqLc7w165w@spectrx.sbay.org>
MIME-Version: 1.0
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My commendations to the authors of the new Secure Device program.

However, with due respect to Mike, Secure Device does -not- make
SecureDrive obsolete, at least not yet.

Certainly there is -no- reason for anyone who has already installed
SecureDrive to switch to SecureDevice. You've already partitioned your
hard disk, so you won't get the main benefit of SDev.

Although SDev has some bells & whistles of it's own, it doesn't have
(yet?) the ability to use/set PGPPASS that I added to SecureDrive, or
the ability to automatically try the hard disk key on diskettes (but
these would be easy to add).

There are some other tradeoffs between SecureDrive and Sdev.

SDev's device driver architecture makes it more compatible with odd
hardware configureations, multiple hard drives, etc., since all
encrypted "volumes" are mapped to DOS files.

OTOH, this same architecture can waste disk space, especially in cases
where SDev encrypted "volumes" occupy most or all of a DOS diskette or
HD partition.  The "outer" FAT and directory in this case are almost
completely wasted.

SDev's device driver also takes about 50% more memory than SECTSR.

OTOH, Sdev's encrypted volumes are safer from accidental writing
if the device driver is not loaded, since they're mapped to read-only
DOS files.

SDev may be a little more secure then SDrv. SDev's checkword to verify
the password is encrypted, while SDrv's is in plaintext. SDev gets
this benefit because encrypted "volumes" have their own encrypted boot
record.  Someone has pointed out that the plaintext checkword could be
used to assist a pre-computed dictionary attack on marginally weak
passphrases.

Another advantage of SDev is that it was developed outside the USA and
so is available world-wide without violating ITAR.  SDrv has "leaked"
overseas to some individuals, but is not, AFIK, being openly
distributed there.

SDev "volumes" always start out encrypted and empty. You can't take an
existing partition or diskette and encrypt it (or decrypt it).  This
may be less convenient especially if disk space is scarce.

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--
edgar@spectrx.sbay.org (Edgar W. Swank)
SPECTROX SYSTEMS +1.408.252.1005  Cupertino, Ca