Raj Kaimal

hell I use it for all random numbers that matter....

Well technically the RNGCryptoServiceProvider won't generate TRULY random numbers either will it? More likely they're just more random than the Random method, it's just another PRNG (Pseudo Random Number Generator) - it anyone aware of the algo used by this method, Yarrow, Fortuna?

Free TIP:
Random class is not sealed.

As result you can easily create SecureRandom adapter RandomNumberGenerator -> Random to not change your code too much and be a little bit more (it's never enough ;o) secure.

I wounder why Microsoft has not supplied this yet. It will be nice to be able retrive Random adapter from RandomNumberGenerator instance. Navigating to betaplace. Done 319404459 ;o)

Scott:
RNGCryptoServiceProvider can be both software and hardware (like Intel RNG) random number generators.

Example:
using System.Security.Cryptography;

const int PROV_INTEL_SEC = 22;
[...]
CspParameters param = new CspParameters(PROV_INTEL_SEC);
RNGCryptoServiceProvider prov = new RNGCryptoServiceProvider(param);
byte[] buff = new byte[100];
prov.GetBytes(buff);

For list of installed providers take a look on
HKLM\SOFTWARE\Microsoft\Cryptography\Defaults\Provider Types

Scott,
I agree that RNGCryptoServiceProvider is not TRULY random but it is the most random one available. To be truly random, one has to grab it from nature - mouse movements, crystal frequency filtering etc.

I read somewhere that RNGCryptoServiceProvider is just a wrapper for CryptGenRandom ( http://msdn.microsoft.com/library/default.asp?url=/library/en-us/security/security/cryptgenrandom.asp ) which from the documentation uses SHA-1.