Failed to connect to database settings

I have an existing sp 2010 enterprise server hosting websites and central administration.  I have a seperate sql 2008 r2 server holding the databases.  My goal is to setup another sp 2010 enterprise server to provide redundancy for the websites and central admin.  I believe I am able to accomplish this by adding another web front end to the farm.  On the second server, I install sp 2010, run the config wizard and connect to the config database located on the sql server, however, I am interrupted at step 3 when I am notified of the following:

Failed to connect to the configuration database.
An exception of type System.InvalidOperationException was thrown.  Additional exception information: There was an error encrypting or decrypting credentials. Either a credential update is currently being performed, or you must update the farm account credentials on this server before you can perform this task.
System.InvalidOperationException: There was an error encrypting or decrypting credentials. Either a credential update is currently being performed, or you must update the farm account credentials on this server before you can perform this task.
   at Microsoft.SharePoint.Administration.SPEncryptedString.CheckCredentialLock()
   at Microsoft.SharePoint.Administration.SPManagedAccount.Deploy(SPApplicat

I use in my ASP.NET MVC application repository pattern and I use in controller for example 3 models:

   namespace MvcApplication1.Controllers  
   {  
        public class HomepageController : Controller  
        {  
            private IWebsitesRepository _repository_websites = new WebsitesRepository();  
            private IFirmRepository _repository_firm = new FirmRepository();  
            private IPhotosRepository _repository_photos = new PhotosRepository();  
      
     
           ...............  
       }  
   }  

In WebsiteRepozitory, FirmRepository and PhotosRepository classes I have:

Database1Entities _entities = new Database1Entities();

So I have 3 connections to database ? Is it wrong ? How can I solve it ?

Protecting application secrets, such as database connection strings and passwords, requires careful consideration of a number of pertinent factors such as how sensitive the data is, who could gain access to it, how to balance security, performance, and maintainability, and so forth. This article explains the fundamentals of data protection and compares a variety of techniques that can be used to protect application settings. The author discusses what to avoid, such as hiding keys in source code and the use of Local Security Authority. In addition, he presents some effective solutions such as the Data Protection API.

Alek Davis

MSDN Magazine November 2003

Robert Hess

MSDN Magazine June 2000

Hi,

I am using visual studio 2005 and sql server 2005.

I am developing a small quiz application and i have stored the connection string in app.config file which is given below.:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
       
        <add name="quizdb"
            connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|Quiz Application.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
            providerName="System.Data.SqlClient" />
    </connectionStrings>
</configuration>

i have retrieved connection string property through configurationmanager class 

and when i m connecting to database  it gives me a runtime error:

Sql Exception was unhandled