reallyrandomguid.cs

public static async Task<Guid> NewReallyRandomGuid()
{
    // Got this value from the 'Create GUID' dialog in Visual 
    // Studio. Guaranteed to be unique.
    var guid = Guid.Parse("43BB5AE8-653E-4985-88F8-A8C4A92C9BD5").ToByteArray();
    
    //Prevent collisions by XORing with random data
    byte[] bytes = new byte[16];
    var rng = new RNGCryptoServiceProvider();
    rng.GetBytes(bytes);
	
    for(int i = 0; i < guid.Length; i++)
    {
        guid[i] = (byte) (guid[i] ^ bytes[i]);
    }
    return new Guid(guid);
}