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1. #Valid starcraft cd key license key
2. #Valid starcraft cd key full
3. #Valid starcraft cd key verification
4. #Valid starcraft cd key Offline

Although this practice is becoming more and more prevalent, I still do not appreciate it as a user, so will not ask my users to put up with it.

#Valid starcraft cd key license key

We must be able to blacklist (revoke) a license key in the case of chargebacks or purchases with stolen credit cards. License keys must be easy enough to type in.

#Valid starcraft cd key verification

Anyone taking the time to disassemble the code would be able to find the graphing function and encryption keys, then mock up a key generator, but its probably quite useful for slowing down casual piracy.Ĭheck tis article on Partial Key Verification which covers the following requirements: It is however very much security by obscurity. Its a fairly small amount of code which would allow for a huge number of unique and valid keys to be generated The application can then reverse this process (base32 to real number, decrypt, decode the points) and then check each of those points is on our secret graph.

We'll encrypt the string with a known and fixed key (horribly weak, but it serves a purpose), then convert the resulting bytes through Base32 to generate the final key The plotted line can have (if you use a fine enough frequency) thousands of unique points, so you can generate keys by picking random points on that graph and encoding the values in some wayĪs an example, we'll plot this graph, pick four points and encode into a string as "0,-500 100,-300 200,-100 100,600" I'm not very well versed in mathematics, but it struck me that one way to do this is to use a mathematical function that plots a graph

#Valid starcraft cd key Offline

With offline verification the most difficult thing is ensuring that you can generate a huge number of unique licence keys, and still maintain a strong algorithm that isnt easily compromised (such as a simple check digit) Most of the other answers address online verification, which is significantly easier to handle (most of the logic can be done server side). When I originally wrote this answer it was under an assumption that the question was regarding 'offline' validation of licence keys. Then, when someone enters a playtime-card number, check if it's in the database, and if it is, associate that number with the current user so it can never be used again.įor online services, there is no reason not to use the above scheme using anything else can lead to problems. Store it in our database and print it on the card.Generate a very large cryptographically-secure random number.The CD-key algorithm for World of Warcraft - used, for instance, when buying playtime cards - probably looks something like this: REAL CORRECT WAY TO DO IT:įor online-services, life is a bit simpler, since even with the binary file you need to authenticate with their servers to make any use of it (eg. Of course, no matter what you do, unless you are offering an online service (like World of Warcraft), any type of copy protection is just a stall: unfortunately, if it's any game worth value, someone will break (or at least circumvent) the CD-key algorithm, and all other copyright protections.

#Valid starcraft cd key full

The full algorithm is rather complex, but outlined nicely in this (completely legal!) paper, published in Germany. Additionally, it requires online activation. This allowed MS to both verify your key and obtain the product-type (Home, Professional, etc.) at the same time. Windows XP takes quite a bit of information, encrypts it, and puts the letter/number encoding on a sticker. The algorithm for verifying is public, and looks something like this: x = 3 Thus, you could enter anything for the first 12 digits, and guess the 13th (there's only 10 possibilities), leading to the infamous 1234-56789-1234

Starcraft and Half-life both used the same checksum, where the 13th digit verified the first 12. For old-school CD keys, it was just a matter of making up an algorithm for which CD keys (which could be any string) are easy to generate and easy to verify, but the ratio of valid-CD-keys to invalid-CD-keys is so small that randomly guessing CD keys is unlikely to get you a valid one.