On 11/11/11 2:02 PM, Development wrote: > Well your average dolt that jailbreaks and knows absolutely nothing > about it would be blockaded. It's the folks that have hex editors and > the time to figure it out that will find it easy. Which is still a > little too much for many JB'ers. Besides, I want to see it broken so > I can figure out how to stop it from happening in the next point > release. That said... On my mac software I have a library I've > written that makes cracking more difficult than using a hex editor > and changing some bools. Specifically it uses a non MD5 hash to > detect the slightest change in the binary, libraries or data files. > Thus far, recompiling alone with absolutely no changes to the code > will fail the hash check. Its been fairly successful. But I don't > really understand code signing that well. so I am curious if such a > hash would be possible on an iOS app. My understanding tells me that > it would not work. The problem being of course that the hash is done > after the app is built, archive builds preclude the inclusion of an > after the fact data file.
(Insert obligatory statement about cryptography being hard here.) Setting aside all the technical issues, do you have evidence that jailbreak piracy is a large enough problem to justify you doing all this? For one, while I don't have a percentage I'm quite certain that it is a minority of phones that are jailbroken. I run with a pretty tech savvy crowd and I know only _one_ person who has jailbroken their phone, and I am fairly confident that techies are more likely to go through the trouble. (How many average users have the faintest idea of what it means to "jailbreak" a device?) Jailbreaking is probably more prevalent in countries and cultures with less of a tradition of paying for software. But this leads to the second point... >From your standpoint you (presumably) really care about converting would-be software pirates into _paying customers_. If they can't use your app on a jailbroken device yet don't buy it legitimately, you haven't accomplished anything economically worthwhile. In fact, you may be worse off because you lose the (admittedly small) possibility that the would-be pirate will show off your app to others who might in turn become paying customers. So, your calculus ought to be something like: (# users with compatible devices) * (% with jailbroken devices) * (% interested in your app) * (% unable or unwilling to circumvent your protection) * (% who will purchase your app when confronted with copy protection) * ($ price per sale) > (increase in legitimate sales that could be obtained by devoting development resources to product enhancement, marketing, support, etc.) Let's suppose that 250M compatible devices have been sold, with 150M distinct users (assuming that there are many people who have replaced devices or own iPad with an iPhone, etc.) Suppose 10% are jailbroken, which is what some cursory Googling turns up. That gives us 15M candidate users. Now, unless you are writing Angry Birds, it seems unlikely that you will appeal to any more than 1% of the user base. That leaves 150K users. Maybe 80% are unwilling to circumvent your copy protection, leaving 120K users. Now the kicker: how many are then going to want to actually buy the app? Maybe 5%? That puts you at 6000 users. So with these admittedly crude guesstimates, if you could gain even 6000 users (out of the 135M non-jailbroken user base postulated above) by devoting your time and energy to anything else, you'd come out ahead. Do you think that is not possible? Do you disagree with the analysis? (I'm not asking rhetorically; I have based my own decisions on such an analysis and would welcome criticism or clarification.) -- Conrad Shultz Synthetiq Solutions www.synthetiqsolutions.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
