/**
  * Computes the hashed version of a password using a unique salt
  * for this password. A unique salt is generated if needed
  * @return string
  */
 protected function ComputeHash($sClearTextPwd)
 {
     if ($this->m_sSalt == null) {
         $this->m_sSalt = SimpleCrypt::GetNewSalt();
     }
     return hash('sha256', $this->m_sSalt . $sClearTextPwd);
 }