copy-protection

This is a followup to this question . The accepted answer is generally sufficient, but requires user to supply personal information (e.g. name) for generating the key. I'm wondering if it's possible to generate different keys based on a common seed, in a way that program would be able to validate if those keys belong to particular product, but without making this process obvious to the end user. I mean it could be a hash of product ID plus some random sequence of characters, but that would allow user to guess potential new keys. There should be some sort of algorithm difficult to guess. The

Is it possible to protect flv files from download? I'd like to protect my files from download but I don't have the money for a streaming server which I think provides some sort of protection. The files are streamed via PHP and are located in an upload folder on my server. I've used PHP to ensure that only subscribers can view the video but I basically want to go a step further and prevent subscribers from, upon login, downloading my videos with downloaders such as Sothink Flv Downloader for Firefox. I fully agree with the DRM consensus of other answers. But would like to add... There are a

How can I add license to my C# desktop application? I need to find a suitable free method to prevent unauthorised users installing my software. Dr Herbie There are plenty of license management systems out there for .NET (there's even one built-in for licensing controls ). A quick Google around for ".NET licence manager" threw up the Open License system, which is free. I expect you can easily find more. I'm probably a bit late, but I spent a bit of time trying to work out a quick and effective method of securing a little C# application, and I would like to share my results. It seems you can

So we've been through this several times now, we release a game (for cheap) and someone hacks it and puts it up on a mirror. We setup Google Alerts for all our apps, so we get told daily who's doing the hacking. So far, we have implemented the licensing service as Google has suggested, our salt is randomly made each time the license is initiated with the unique device ID. We run the check service once, when the application is started for the first time. We then generate a 512 character hash for the key and the stored value that is compared against in SharedPreferences from there on out. Now, I

I'm thinking about adding some kind of copy protection to one of my tools. Do you have any experience with that? Have you developed your own protection techniques or did you buy 3rd party software? Do you think it is a viable method to increase sales? (In a private and/or corporate environment) What do you do to prevent hassling your paying customers? In most cases it's the paying customers who suffer from a bad copy protection, and I don't want this to happen to my customers. (Even if that means accepting some freeloaders) I'm especially interested in techniques which allow a trial or