String strTimestamp = request.getHeader( HEADER_TIMESTAMP );

        // no signature or timestamp
        if ( ( strHash1 == null ) || ( strTimestamp == null ) )
        {
            LOGGER.info( "SignRequest - Invalid signature" );

            return false;
        }

        if ( !isValidTimestamp( strTimestamp ) )
        {
            LOGGER.info( "SignRequest - Invalid timestamp : " + strTimestamp );

            return false;
        }

        List<String> listElements = new ArrayList<String>( );

        for ( String strParameter : getSignatureElements( ) )
        {
            String strValue = request.getParameter( strParameter );

            if ( strValue != null )
            {
                listElements.add( strValue );
            }
        }

        String strHash2 = buildSignature( listElements, strTimestamp, getPrivateKey( ) );

        return strHash1.equals( strHash2 );
    }

    /**
     * {@inheritDoc }
     */
    @Override
    public AuthenticateRequestInformations  getSecurityInformations( List<String> elements )
    {
        String strTimestamp = String.valueOf( new Date( ).getTime( ) );
        String strSignature = buildSignature( elements, strTimestamp, getPrivateKey( ) );

        return new AuthenticateRequestInformations().addSecurityHeader(HEADER_TIMESTAMP,strTimestamp).addSecurityHeader(HEADER_SIGNATURE, strSignature);