#CD-ROM copy protection
9 messages in this thread
Is there a way to make each CD-ROM in a large pressing unique? I am trying to
make a disk that will unlock only specific areas depending on a code number of
some sort. I think Adobe has done this, somehow allowing you to purchase fonts
over the phone and they give you a password to unlock the CD. Any info on how
this is done would be appreciated.
Larry
Larry:
In the case of Adobe that you mentioned, you don't really want each disc to be
unique. You want each un-lockable section to be uniquely un-lockable in a way
known only to you. Then, when your customer wants to buy a font, or a piece of
software, or whatever, you can give them a code which your software understands
allows access to only that portion of the disc. This is the way to get around
the issue that – by definition – all discs mastered from a single master, are
exactly alike.
Hope this helps! Best – Rich
Do you know specifically how to accomplish this in software without making each
disc unique? Also, what's to keep a user from giving away the code to his or
her friends, etc. and having the code unlock their disk as well?
Larry
Larry:
Do I know specifically how to do this? No, but conceptually it is simple. The
retrieval software loads a segment to your hard disk, with a table (or space
for a table) that indicates key passwords. When you go to access an area of
the CDROM, the retrieval software checks to see if a) it is locked and b) if
the password has been entered on the table. If you have entered the password,
you get to the data you sought.
Why wouldn't people pass the password around? In theory, I suppose there's no
reason, but since the password probably cost you $$, what is your motivation
for giving it to someone who hasn't? There is no scheme that is foolproof, but
this one so far has served a few dozen vendors well. And since you can't put a
unique id on each CDROM, it is one of a limited set of options.
Best – Rich
Rich,
Actually, you can put a unique id on each disc, if they are one-offs.
Kathy <<– The One-Off CD Shop MidSouth, Inc.
Kathy:
Right, but the fellow who who started the thread asked about volume production.
Best – Rich
Rich,
Also, you can key the passwords off the serial number of the retrieval
software (presumably distributed on floppy). I can still think of ways to get
around it, but they require bvuying the CDROM but then using someone elses
install disk.
Frank
Contact the AND group inc. 11th floor 940 Sixth Ave. SW Calgary, Alberta Canada
T2P 3T1 403-232-6211. They do exactly what you want. They can even lock
portions of the disc until someone purchases an access code.
Thanks for the info on AND group.
Larry