我已经在我公司的软件(c# .net)上实现了基于互联网的一次性激活，它需要一个许可证密钥，该密钥指向存储在服务器数据库中的许可证。软件用密钥攻击服务器，并获得许可信息，然后使用客户端计算机上的一些变量(CPUID和其他不经常更改的东西的组合)生成的RSA密钥在本地加密，然后将其存储在注册表中。

它需要一些服务器端编码，但它对我们来说工作得非常好，当我们扩展到基于浏览器的软件时，我能够使用相同的系统。它也给你的销售人员提供了关于谁，在哪里，什么时候使用软件的很好的信息。任何只在本地处理的许可系统都很容易被利用，特别是在。net中反射时。但是，正如其他人所说，没有一个系统是完全安全的。

在我看来，如果你不使用基于网络的授权，保护软件就没有任何意义。由于数字版权管理可能引起的头痛，这对已经为此付费的用户来说是不公平的。

我不知道你想说得多详细

但我相信。net可以访问硬盘序列号。

你可以让程序把它和其他东西(比如网卡的用户名和MAC地址)发送给你

你在此基础上计算出一个代码，然后把密钥发邮件给他们。

他们会阻止他们在拿到钥匙后换机器。

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.

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。

除了已经说过的....

由于中间语言的问题，. net应用程序的任何使用本质上都是容易被破坏的。对. net代码进行简单的反汇编就可以向任何人打开您的产品。他们可以很容易地绕过你的授权代码。

你甚至不能再使用硬件值来创建键了。虚拟机现在允许人们创建一个“许可”机器的映像，并在他们选择的任何平台上运行它。

如果软件价格昂贵，还有其他解决方案。如果不是，那就给普通黑客制造足够的难度。接受这个事实，即最终会有未授权的副本出现。

如果你的产品很复杂，固有的支持问题将为你创造一些保护。

我坚信，只有基于公钥密码学的许可系统才是正确的方法，因为您不必将许可证生成所需的基本信息包含到源代码中。

在过去，我曾多次使用Treek的授权库，因为它满足了这一要求，并提供了非常好的价格。它对终端用户和自身使用相同的许可证保护，直到现在还没有人破解它。你也可以在网站上找到避免盗版和破解的好建议。