RNGCryptoServiceProvider Class
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RNGCryptoServiceProvider Class

Implements a cryptographic Random Number Generator (RNG) using the implementation provided by the cryptographic service provider (CSP). This class cannot be inherited.

Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)

public ref class RNGCryptoServiceProvider sealed : public RandomNumberGenerator
/** @attribute ComVisibleAttribute(true) */ 
public final class RNGCryptoServiceProvider extends RandomNumberGenerator
public final class RNGCryptoServiceProvider extends RandomNumberGenerator

The following code example shows how to create a random number with the RNGCryptoServiceProvider class.

// The following sample uses the Cryptography class
// to simulate the roll of a dice.

using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Security::Cryptography;

int RollDice(int numberSides)
    // Create a byte array to hold the random value.
    array<Byte>^ randomNumber = gcnew array<Byte>(1);

    // Create a new instance of the RNGCryptoServiceProvider.
    RNGCryptoServiceProvider^ cryptoProvider =
        gcnew RNGCryptoServiceProvider();

    // Fill the array with a random value.

    // Convert the byte to an integer value to make the modulus operation
    // easier.
    int rand = Convert::ToInt32(randomNumber[0]);

    // Return the random number mod the number of sides.  The possible
    // values are zero-based, so we add one.
    return (rand % numberSides) + 1;
int main()
    // Roll the dice 30 times and display
    // the results to the console.
    for (int i = 0; i <= 30; i++)


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0

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