asp.net - 中程度の信頼できるホスティング環境での Paypal DoDirectPayment メソッドの実装?

Question

ASP.NET MVC 3 アプリケーションに取り組んでおり、Paypal SDK for Paypal Website Pro を使用しています。

以下のような API クレデンシャルを作成しました。

using System;
using com.paypal.sdk.services;

using com.paypal.sdk.profiles;
using com.paypal.sdk.util;
/**

 */
namespace GenerateCodeNVP
{
public class DoDirectPayment
{
    public DoDirectPayment()
    {
    }
    public string DoDirectPaymentCode(string paymentAction,string amount,string     
creditCardType,string creditCardNumber,string expdate_month,string cvv2Number,string 
firstName,string lastName,string address1,string city,string state,string zip,string 
countryCode,string currencyCode)
    {
        NVPCallerServices caller = new NVPCallerServices();
        IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
        /*
         WARNING: Do not embed plaintext credentials in your application code.
         Doing so is insecure and against best practices.
         Your API credentials must be handled securely. Please consider
         encrypting them for use in any production environment, and ensure
         that only authorized individuals may view or modify them.
         */

        // Set up your API credentials, PayPal end point, API operation and version.
        profile.APIUsername = "sdk-three_api1.sdk.com";
        profile.APIPassword = "QFZCWN5HZM8VBG7Q";
        profile.APISignature = 
"AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
        profile.Environment="sandbox";
        caller.APIProfile = profile;

        NVPCodec encoder = new NVPCodec();
        encoder["VERSION"] =  "51.0";   
        encoder["METHOD"] =  "DoDirectPayment";

        // Add request-specific fields to the request.
        encoder["PAYMENTACTION"] =  paymentAction;
        encoder["AMT"] =  amount;
        encoder["CREDITCARDTYPE"] =  creditCardType;        
        encoder["ACCT"] =  creditCardNumber;                        
        encoder["EXPDATE"] =  expdate_month;
        encoder["CVV2"] =  cvv2Number;
        encoder["FIRSTNAME"] =  firstName;
        encoder["LASTNAME"] =  lastName;                                        
        encoder["STREET"] =  address1;
        encoder["CITY"] =  city;    
        encoder["STATE"] =  state;          
        encoder["ZIP"] =  zip;  
        encoder["COUNTRYCODE"] = countryCode;
        encoder["CURRENCYCODE"] =  currencyCode;    

        // Execute the API operation and obtain the response.
        string pStrrequestforNvp= encoder.Encode();
        string pStresponsenvp=caller.Call(pStrrequestforNvp);

        NVPCodec decoder = new NVPCodec();
        decoder.Decode(pStresponsenvp);
        return decoder["ACK"];

    }
}

}

しかし、paypal SDK が私に中程度の信頼の問題を与えているため、成功を収めることができません。

エラーの説明は次のとおりです。

That assembly does not allow partially trusted callers

これを回避する方法を知っている人はいますか?

前もって感謝します。