On Jan 1, 2010, at 2:11 PM, Uli Kusterer wrote: > On 29.12.2009, at 21:24, Benjamin Rister wrote: >> It’s not a serial number collision that causes the inconvenience for your >> real customers. >> >> Once there’s a keygen, you have no way of distinguishing a legit serial from >> a non-legit serial using your algorithm, period. The only remedy is to >> change to another algorithm, retroactively invalidating all of your paying >> customers serials in the process. You can’t just start issuing new serials >> without impacting existing customers, because again, you have no way of >> distinguishing in the field whether this is a paid customer or not. > > Well, usually people keep a record of issued serial numbers. Depending on > your scheme this can be keeping the name and e-mail used to register, so you > can generate the key again, or the range of "seed" numbers the newest batch > of keys was generated from, or whatever. > > If your records show you never issued a key, you know it's not legitimate.
The key phrase was “in the field”; it’s not that the knowledge doesn’t exist, it’s just not usable. If your software has to check back with your licensing servers in order to validate a serial, you’re now talking about an activation scheme, in which symmetric vs. asymmetric etc. becomes academic. Under a standard serial scheme, following a keygen you have no choice but to change algorithms and invalidate all existing licenses, full stop. Who you choose to issue new licenses to is a separate matter, and I can’t think of any possible way to do this without inconveniencing and annoying your legitimate users. Best, br -- Benjamin Rister President, Decimus Software, Inc. http://decimus.net/ ------------------------------------ MacSB email guidelines: http://tinyurl.com/2g55d6 Use MacSB-Talk for off topic messages: http://groups.google.com/group/macsb-talk Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/macsb/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/macsb/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
