In article <1993Apr21.141137.863@imag.fr> schaefer@imag.imag.fr (Arno Schaefer) writes: >In article <1993Apr21.085848.12704W@lumina.edb.tih.no>, ketil@edb.tih.no (Ketil Albertsen,TIH) writes: >|> In article <1993Apr20.230749.12821@reed.edu>, mblock@reed.edu (Matt Block) writes: >>>	I guess what I am saying is that your question is difficult, if not >>>impossible, to answer. What exactly do you want to know?  Do you need a good >>>one for a project you are working on? How secure must it be?  Are you trying >>>to crack one that someone else has used?  I can probably make suggestions, >>>assuming the activity is strictly legal.  (In general, it is a BAD idea, >>>legally, to tamper with copy protection.  It can also lead to corruption of >>>files which you necessarily do not have back ups of (being as they are copy >>>protected,) which can be devestating.)  Do you have absolutely no ideas for >>>practical applications, and are merely curious? >>>	Please clear up those questions, and I'll try to help as much as I >>>can. >>  >> May we interpret this as an offer to volunteer as editor for a >> "Copy protection FAQ" ? I am quite sure that I am not alone welcoming such >> an initiative! *I* will volunteer to ask some of the questions, if you will >> provide the answers :-) >>  >Hey, now will you stop encouraging him? Copy protection only serves one pur- >pose: to keep the honest buyer from making (legal) backup copies. It will >definitely not stop any pirates. If you want to protect you soft, supply a >good documentation and support. This is IMHO the *only* way of effectively  >protecting software.  There are several types of copy protection, and the point is to make sure the user is using a legitimate copy.  The simplest and virtually fool-proof way is for the program to somehow fixate itself to the machine it was installed on (some sort of checksum, serial number, whatever) so a copy put on a different machine (NOT installed from original disks) will not work.    The program is definitely backupable, if restored to the same machine (depends on the programmer...  don't use a disk drive characteristic!)  If the user  did an upgrade to the machine, he/she should reinstall all programs any way. No document look-up, no disk wear-and-tear!  I did not say that the originals would allow only one install.  The user's  conscience should do that.  I know, I'll get flamed for this...  But with the increasing number of "casual" users who either unknowingly or don't care about the software copyrights (It's the truth.  I have "friends" who ask me for copies of my latest games all the time, and when I refused, they went after somebody else.), casual pirating is becoming more of a problem.  Some sort of copy protection will discourage the casual copying.  I've seen what some of my "friends" dug up somewhere...  Latest and the greatest games, all cracked, WITHIN days of actual release!  You know how many bytes you need to change in X-wing to disable the quiz?  TWO!  Yes, TWO!  (And don't ask me which ones they are.)  Determined pirates are unstoppable, given enough time, but their results do not spread  that far, since pirate boards are not that well-known, and easily tracked once found by authorities.  It is the "casual" pirates that the copy protection is determined to discourage.  What I believe the companies should do is implement the above plus a special patch once the user registers that loudly exclaims upon bootup "REGISTERED TO XXXXX -- address, city, state zip" and disables the above. Two benefits: 1) encourages registration, 2) cuts down on pirating and makes it more traceable, because if the patch's registration message is encrypted, it will be quite hard to change, and therefore provides a stable trail of who allowed their copy out of their hands, and thus violated their license agreement.  This way, the legitimate users who does not register will experience minimal  discomfort (who does major upgrades to their computer frequently?) as only problem they have is they won't be able to restore to another computer.  The registered users would have proven they are legitmate users and therefore gains full rights, and can restore to different machines.  On the other hand, the software company now have a record of where THIS particular copy is  supposed to be.  If this user's copy was found to be somewhere it was not  supposed to be, we know who has broken their license agreement.  Of course, a hacker can break that eventually, but that's not the point, is it?