<p>I've encrypted the connectionstring in my web.config file using the steps in the link below:
<a href="http://www.codeproject.com/KB/database/WebFarmConnStringsNet20.aspx" rel="nofollow noreferrer">http://www.codeproject.com/KB/database/WebFarmConnStringsNet20.aspx</a></p>

<p>However, whenever I call my application, it will give the following error:  </p>

<blockquote>
  <p>Failed to decrypt using provider
  'CustomProvider'. Error message from
  the provider: The RSA key container
  could not be opened.</p>
</blockquote>

<p>The server where I perform the encryption is a 64-bit Windows Server 2003 R2 SP2. Because of that I assign the ACL to <code>NT Authority\Network Service</code>. Yet it still doesn't work.  </p>

<p>Hope someone has some ideas what else do I need to check to get this working.</p>

<p>PS. If I used the default rsa key <code>NetFrameworkConfigurationKey</code> for encryption, then the connection string will not have an access problem. </p>

Did you remember to add the
```
```
<configProtectedData>
```
```
to your web.config?