Thin driver data encryption and integrity

I am having problem with connecting to my database using the JDBC thin driver’s Advanced Security features.
Sample of my code:

Properties securityPro = new Properties();
securityPro.put(“oracle.net.encryption_client”, “REQUIRED”);
securityPro.put(“oracle.net.encryption_types_client”, “( DES40C )”);
securityPro.put(“oracle.net.crypto_checksum_client”, “REQUESTED”);
securityPro.put(“oracle.net.crypto_checksum_types_client”, “( MD5 )”);
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection con = DriverManager.getConnection(dbName, securityPro);

Exception:
java.sql.SQLException: invalid arguments in call

at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:168)

at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:210)

at oracle.jdbc.dbaccess.DBError.check_error(DBError.java:857)

at oracle.jdbc.ttc7.TTC7Protocol.logon(TTC7Protocol.java:189)

at oracle.jdbc.driver.OracleConnection.(OracleConnection.java:249)

at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:365)

at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:260)

at java.sql.DriverManager.getConnection(DriverManager.java:512)

at java.sql.DriverManager.getConnection(DriverManager.java:140)

From the documentation, it seems very simple to use. However, it is not working for me yet. Could anyone help me? Thanks