What's the best library to generate random numbers for cryptographic keys in .NET? [closed]

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In .NET, you can generate RSA key pairs using RSACryptoServiceProvide. But is that the best option in .NET to generate truly rand开发者_高级运维om numbers? There are tons of other open source libraries, such as CryptoPlusPlus, that can be used to generate random number. I would like to hear from other experts' opinions. Thanks in advance for your two cents.

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I wouldn't personally go anywhere other than RNGCryptoServiceProvider unless somebody provides a proof that it sucks.

The actual implementation used by this class is not obtainable because it's implemented as part of the runtime (System.Security.Cryptography.Utils._GetBytes or System.Security.Cryptography.Utils._GetNonZeroBytes) which, for me, is heartening since I would hope that the implementation would bring at least ambient information in from the host to generate the data.

I do believe these are routed through to lower level win32 apis which, of course, would be patched if a security hole is found in them (well... hopefully!)

How it's done in Mono, however, I wouldn't know.

For the extremely paranoid

The real problem with any of this is that your randomness in .Net can be broken by a malicious hacker by changing the host behaviour (that is - by writing a modified runtime). This is much easier in a VM-style platform like .Net or Java than it is in native code (which would require hacking the lower-level platform or modifying the hardware).

Curiously, using RNGCryptoServiceProvider makes this a lot easier since these aforementioned internal calls are implicitly trusted by the managed part of the .Net framework.

However - in reality - your code is going to have to be something really special for someone to want to go to all that effort. So personally I'd still use RNGCryptoServiceProvider.

But it's why I have a real problem with attempts a crypto libraries and functions written in javascript - a quick browser hack can screw it all.

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Classes derived from RandomNumberGenerator generate truly random numbers.

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You could get them from random.org if your project allows that. That should be random enough.