Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!wuarchive!uunet!munnari.oz.au!ariel!ucsvc.ucs.unimelb.edu.au!u3364521 From: U3364521@ucsvc.ucs.unimelb.edu.au (Lou Cavallo) Newsgroups: comp.sys.amiga Subject: Re: Copy protection (was Re: Awesome! No I am Pi**ed!) (LONG) Message-ID: <1366@ucsvc.ucs.unimelb.edu.au> Date: 8 Dec 90 12:16:50 GMT References: <1990Dec5.041002.453@sbcs.sunysb.edu> <1990Dec5.205822.216@evax.arl.utexas.edu> Organization: I.A.E.S.R., Melbourne University Lines: 71 G'day, I'm interested in *only* the technical merits of copy protection schemes and I am offering my thoughts below in the hope of raising the bandwidth for the thread in discussion. Adam Hill (hill@evax.arl.utexas.edu ) writes: > Ok how about this scheme: > A program is encrypted. The program is DECRYPTED by a program who searches > [...] I've read the followups to this posting and I agree with their objections of the possibility of tracing/using the DECRYPTING code to circumvent this type of copy protection ... if you can get at the code that does the decrypting *or* you can get at some form of the decrypted program (eg with a C64 like freeze machine, there is 1 on the market no?). In this thread an earlier posting stated that the poster had never seen any form of protection that had not been cracked, which set me to thinking ... 1. I've not seen or heard of pirated versions of Superbase for the Amiga. I believe that this program is dongle protected. {I do not use and hence I do not seek out pirated s/w so I may be merely ignorant of the facts of the matter here.} Question{s}: is it very easy (or hard) to overcome dongle protection? 2. If a decryption scheme was placed into a dongle device with a CPU it may be possible (although I cannot think of a way) to execute the decrypting code from the "dongle" and to not allow tracing of the code. {I believe this would be way too slow for practical use however it illustrates the question I am thinking of phrasing.} Question: if one has decryption code that does not reside in Amiga RAM (and hopefully not accessible by an Amiga run program) is it necessary to have all of the *decrypted* program reside in AmigaRAM? If the answer to Q 2. is in principle no, then an encrypted program could be decrypted and then executed 1 instruction at a time, no? I can only see that a code monitor of some sort could trace/trap the instructions. However as the instruction flow would depend on the users usage patterns the tracing of the execution flow should only give a partial picture of the code for the original program. A partial copy of a complex program would be next to worthless no? There are a lot of ``if's'' in my argument so it presumably breaks down some where. I'd be interested in explanations of why if they help explain how my Amiga works when running executable code. Thanks in advance. At this stage I want to disclaim some of the above and to exclaim some of my points of view. 1. I don't want copy protection. {I just want piracy to go away. :-)} 2. I realise dongle is a dirty word. The only kind of dongle I could *ever* tolerate would be one that was *useful* to me. Perhaps dongles should be built into useful products ... like a free replacement mouse? :-) 3. I am discussing this at all because of intellectual curiosity. I hope I'm not going to be flamed because of that. {Please. :-)} 4. I think such a method (if it was workable) would be HORRENDOUSLY complex. I would probably not buy s/w protected in such a way. {No smiley.} > Most Common Phrase at DevCon '90 - "Shhhhhhh.." { This is one of my favourite quotes in quite a while. } yours truly, Lou Cavallo.