class Program
{
    static void Main(string[] args)
    {
        string exponent = "010001";
        string modulus = 
            "A3A69317FB92A534912A0999A7EEE826358C05F434C5E1E" +
            "DB61C68E882CE52F7573FA44CE46E858673A8A328E17712F" +
            "DAAECF383F13ECC1FD9D1505D2F23C983AD36F951788DEE30F1A" +
            "E2A34F2DB13E46C409980A5467E05C7667AAD896464ABB073AA01AAF" +
            "E130E28FA4D3D6A57ECA8422A482E22C5E0BA67434160B95A68DF";
            
        RSAParameters rsaParameters = new RSAParameters()
        {
            Exponent = FromHex(exponent), // new byte[] {01, 00, 01}
            Modulus = FromHex(modulus),   // new byte[] {A3, A6, ...}
        };
        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
        rsa.ImportParameters(rsaParameters);
        byte[] sample = rsa.Encrypt(Encoding.UTF8.GetBytes("hello world"), false);
    }
    static byte[] FromHex(string hex)
    {
        if (string.IsNullOrEmpty(hex) || hex.Length % 2 != 0) throw new ArgumentException("not a hexidecimal string");
        List<byte> bytes = new List<byte>();
        for (int i = 0; i < hex.Length; i += 2)
        {
            bytes.Add(Convert.ToByte(hex.Substring(i, 2), 16));
        }
        return bytes.ToArray();
    }
}

------解决方案--------------------
试试这个：
RSAParameters Exponent 是三个字节，一般固定是0x01, 0, 0x01

byte[] plainData = new byte[117];// 明文数据;
RSACryptoServiceProvider rsaPub = new RSACryptoServiceProvider();
RSAParameters rparam = new RSAParameters();
rparam.Modulus = mods;
rparam.Exponent = new byte[] { 1, 0, 1 };
rsaPub.ImportParameters(rparam);
byte[] enData = rsaPub.Encrypt(plainData, false);