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From: kdenning@genesis.Naitc.Com (Karl Denninger)
Newsgroups: comp.org.eff.talk,alt.privacy,alt.censorship
Subject: Re: Prodigy charged with invading users' privacy
Summary: Procedure to do a "clean room" test.
Message-ID: <1991May1.051734.24594@pcserver2.naitc.com>
Date: 1 May 91 05:17:34 GMT
References: <1991Apr30.185752.4913@mnemosyne.cs.du.edu> <1991Apr30.225133.8165@craycos.com>
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In article <1991Apr30.225133.8165@craycos.com> jrbd@craycos.com (James Davies) writes:
>>     I received a call from someone from another user group who read
>>our newsletter and is very involved in telecommunications.  He
>>installed and ran Prodigy on a freshly formatted 3.5 inch 1.44 meg
>>disk. Sure enough, upon checking STAGE.DAT he discovered personal data
>>from his hard disk that could not have been left there after an
>>erasure.
>
>Question: was he using an unused disk, or did he just reformat an old
>one, assuming that it would be wiped clean?
>
>Could some Prodigy user out there try this experiment again, this
>time using a verifiably empty disk?  I get the feeling that this hasn't
>exactly been a controlled experiment so far...


Note one thing well:

All formats on a floppy disk ARE LOW LEVEL FORMATS.  That is, all data is
physically erased, sector marks are rewritten, the whole works.

It is not possible on a DOS machine to issue a "FORMAT A:" and have any data
retained on the diskette from prior use.

Try it.  You'll see that this is the case.

To do a controlled test, do the following:

1)	Bulk erase and then format a floppy diskette.  NO CHANCE of any
	residual data on the disk surface after this.

2)	Run a "cleandisk" program to write ZEROS to all unallocated areas of
	the fixed disk in the machine.  This will guarantee that all
	unallocated areas, which may be used for scratch buffers, have no
	data on them.  The tail end of files are irrelavent -- that's an
	ALLOCATED area and should not be touched by the software if it's
	being "honest".

3)	Install Prodigy on the floppy disk.  Do not touch the hard drive, 
	or run any software from it.  Work >only< on the floppy disk.

4)	Call Prodigy.  Spend an hour or two online.  Give 'em plenty of time
	to hose you if they're going to.

5)	Sign off and look at STAGE.DAT on the floppy disk.


Alternately, after cleaning the disk, install the Prodigy software on the
fixed disk.  DO NOT ACCESS ANY OTHER PROGRAMS OR DATA.  Immediately run
Prodigy, dial in, and use it for a couple of hours.

Then check STAGE.DAT on the fixed disk.  

Since you zeroed all unallocated areas on the drive before you began, there
is no way the STAGE.DAT file could have gotten private data in it unless the
software is scanning your fixed disk drive.

This should provide rather conclusive proof one way or the other.

I'm not a Prodigy subscriber, or I'd try this...

--
Karl Denninger - AC Nielsen, Bannockburn IL (708) 317-3285
kdenning@nis.naitc.com

"The most dangerous command on any computer is the carriage return."
Disclaimer:  The opinions here are solely mine and may or may not reflect
  	     those of the company.