在生成密钥时，不要忘记将版本和构建号连接到计算散列的字符串上。这样就不会有一把钥匙能打开你释放的所有东西。

当你在astalavista.box.sk中找到一些密钥或补丁后，你就会知道你成功地让某些东西变得流行，以至于有人费心去破解。喜乐!

我以前用过Crypkey。这是许多可用的之一。

使用任何许可方案，您只能在一定程度上保护软件。

简单的答案-无论你使用什么方案都可以被破解。

不要用一个旨在防止黑客的系统来惩罚诚实的客户，因为黑客无论如何都会破解它。

一个简单的散列代码绑定到他们的电子邮件或类似的可能就足够了。当人们需要重新安装或更新硬件时，基于硬件的id总是会成为一个问题。

关于这个问题的好帖子: http://discuss.joelonsoftware.com/default.asp?biz.5.82298.34

生成许可密钥的方法有很多，但真正安全的方法很少。这很遗憾，因为对于公司来说，许可证密钥的价值几乎与真正的现金相同。

理想情况下，您希望您的许可密钥具有以下属性:

Only your company should be able to generate license keys for your products, even if someone completely reverse engineers your products (which WILL happen, I speak from experience). Obfuscating the algorithm or hiding an encryption key within your software is really out of the question if you are serious about controlling licensing. If your product is successful, someone will make a key generator in a matter of days from release. A license key should be useable on only one computer (or at least you should be able to control this very tightly) A license key should be short and easy to type or dictate over the phone. You don't want every customer calling the technical support because they don't understand if the key contains a "l" or a "1". Your support department would thank you for this, and you will have lower costs in this area.

那么如何解决这些挑战呢?

The answer is simple but technically challenging: digital signatures using public key cryptography. Your license keys should be in fact signed "documents", containing some useful data, signed with your company's private key. The signatures should be part of the license key. The product should validate the license keys with the corresponding public key. This way, even if someone has full access to your product's logic, they cannot generate license keys because they don't have the private key. A license key would look like this: BASE32(CONCAT(DATA, PRIVATE_KEY_ENCRYPTED(HASH(DATA)))) The biggest challenge here is that the classical public key algorithms have large signature sizes. RSA512 has an 1024-bit signature. You don't want your license keys to have hundreds of characters. One of the most powerful approaches is to use elliptic curve cryptography (with careful implementations to avoid the existing patents). ECC keys are like 6 times shorter than RSA keys, for the same strength. You can further reduce the signature sizes using algorithms like the Schnorr digital signature algorithm (patent expired in 2008 - good :) ) This is achievable by product activation (Windows is a good example). Basically, for a customer with a valid license key, you need to generate some "activation data" which is a signed message embedding the computer's hardware id as the signed data. This is usually done over the internet, but only ONCE: the product sends the license key and the computer hardware id to an activation server, and the activation server sends back the signed message (which can also be made short and easy to dictate over the phone). From that moment on, the product does not check the license key at startup, but the activation data, which needs the computer to be the same in order to validate (otherwise, the DATA would be different and the digital signature would not validate). Note that the activation data checking do not require verification over the Internet: it is sufficient to verify the digital signature of the activation data with the public key already embedded in the product. Well, just eliminate redundant characters like "1", "l", "0", "o" from your keys. Split the license key string into groups of characters.

警告:你不能阻止用户盗版，只能让诚实的用户更容易做正确的事情。

假设你不想为每个用户做一个特殊的构建，那么:

为产品生成一个密钥 取用户名 使用(例如)SHA1连接用户名、密钥和散列 将SHA1散列解压缩为字母数字字符串。这是个人用户的“产品密钥” 在程序中，执行相同的散列，并与产品密钥进行比较。如果相等，好的。

但是，我再重复一遍:这并不能阻止盗版

我最近读到，这种方法在密码学上不是很可靠。但是这个解决方案已经很弱了(因为软件本身必须在某个地方包含密钥)，所以我不认为这个发现会使解决方案失效。

只是觉得我真的应该提一下;如果您打算从这里推导出其他东西，请小心。

我们用来生成许可证密钥的c# / .NET引擎现在是开源的:

https://github.com/appsoftware/.NET-Licence-Key-Generator。

它基于“部分密钥验证”系统，这意味着只有用于生成密钥的密钥子集必须编译到您的分布式文件中。您自己创建密钥，因此许可证实现对于您的软件是惟一的。

如上所述，如果您的代码可以反编译，那么绕过大多数许可系统就相对容易。