El cheapo way to protect a data CD

vbimport

#1

Wanted to see if this collective of brain power could render some assistance. My partner and I are creating an eLearning CD, which will consist of a large EXE file (which compressed a web navigation containing HTML, PDFs, and a bunch of Flash-based files), and will try and market this to a basically non-techie audience.

Question is, is there a inexpensive way to do some basic copy protection so one of these generally-not-computer-superusers will not be able to simply make a copy of the CD and give it to his/her buddy? The content will not be installed on a PC, but run off the CD (did not want to hassle people with having to install and register the software on each PC…).

Do realize that there is no real way to stop a n experienced person from cracking thru… but, was just trying to find a way to dissuade the casual user from doing this.

Any suggestions are highly appreciated!


#2

First of all, Google is your friend:
http://www.google.com/search?hl=en&q="cd+protect+utilities"

I din’t try any of the programs listed on the first result page but they could be a start. But I would test the self-built protected CD on at least 5 different drives. It would be bad if the used protection turns out to be working on only 50% of all common drives. This is the problem you might run into in general.

Some weeks ago I experimented with subchanneldata, Sony and Philips style pregaps and found out that both newer CloneCD and Alcohol have some problems preserving one of both pregap styles - I used “Game CD” profiles or alike.

Basically the following disc layout would even help to make CloneCD and Alcohol backups hard to do:

  1. Three dummy audio tracks after the data track (Tracks 2 to 4)
  2. Sony style pregap for Track 3 (-01.74 to 00.00)
  3. Philips style pregap for Track 4 (-02.00 to 00.01)

Additionally you could put some erroneuous sectors on the data track and test for read errors to occur when trying to access the sectors.

The protection would need a drive capable of reading Q-subchannel data (READ CD) or capable of playing audio through the track boundaries (PLAY AUDIO) and returning the current Q-subchannel (READ SUBCHANNEL) data while doing this. From what I know the second method should work for almost all drives, but I don’t know how frequently and exactly the Q-subchannel data can be read.

In order to identify the disc as original you could test for the following:

  1. There must not be a -02.00 pregap sector before Track 3
  2. There must be a 00.00 pregap sector before Track 3
  3. There must be a -02.00 pregap sector before Track 4
  4. There must not be a 00.00 pregap sector before Track 4

For PerfectRip this shouldn’t be a problem but for CloneCD, Alcohol and Nero 8 it seems to be, those three forming the standard equipment used by the “average” user when dealing with copy protections.

If you’re interested I’ll upload a CloneCD-image example with this layout which has to be burned with CloneCD and contains a little program which performs the check. It could take some days as I currently have a great deal to do on my job.

Please post your opinions about the method.


#3

I learned a heckova lot reading that… many thanks. Will try that over the weekend, and see if I can replicate your results on my disc. Don’t bother uploading quite yet, hate to put you thru any unnecessary work.

I just downloaded CDRWIN, so will muddle thru it while college football is on Saturday (aka, multi-tasking).

Many thanks!