title: ORA-28040: After Upgrade Database to 12c from 11g
body: <h2>Problem Statement:</h2>
  
  <p>We are doing a migration activity in which we have migrated DATABASE from <code>ORACLE 11g</code> to <code>ORACLE 12c</code>.
  After upgrade one of our application which is using  <code>jdk 6</code> with <code>ojdbc6.jar</code> (JDBC Driver) is not able to connect the 12c database. </p>
  
  <p>Below error we are getting :</p>
  
  <blockquote>
  <pre><code>java.sql.SQLException: ORA-28040: 
  No matching authentication protocol
  </code></pre>
  </blockquote>
  
  <p>after Upgrade Database to 12c</p>
  
  <h2>Configuration</h2>
  
  <ul>
  <li>JDK Version : 1.6</li>
  <li>JDBC Driver : <code>ojdbc6.jar</code></li>
  <li>Database Version : Oracle 12c</li>
  <li><code>SQLNET.ALLOWED_LOGON_VERSION_SERVER = 11</code></li>
  <li><code>SQLNET.ALLOWED_LOGON_VERSION_CLIENT = 11</code></li>
  </ul>
  
  <h3>Workaround tried:</h3>
  
  <ul>
  <li>1)  We tried to run a simple jdbc application with jdk1.6 and ojdbc6.jar it was successful. Also it is as per Oracle Compatibility matrix. <br></li>
  <li>2)  We asked to update the parameter <code>SQLNET.ALLOWED_LOGON_VERSION_SERVER = 8</code> but security team cannot do it as it does not comply on security standards.</li>
  </ul>
  
  <p>Please suggest how we should proceed forward to fix this issue.</p>