cleaner way to generate a unique id

gistfile1.txt

private static readonly RNGCryptoServiceProvider random = new RNGCryptoServiceProvider();

private string GenerateUniqueID(int length)
{
    // We chose an encoding that fits 6 bits into every character,
    // so we can fit length*6 bits in total.
    // Each byte is 8 bits, so...
    int sufficientBufferSizeInBytes = (length * 6 + 7) / 8;

    var buffer = new byte[sufficientBufferSizeInBytes];
    random.GetBytes(buffer);
    return Convert.ToBase64String(buffer).Substring(0, length);
}