ORA-12647: Authentication required
Cause : The parameter that controls whether authentication is required was set to true, but the executable does not have an authentication service linked in.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Either re-link the executable with an authentication service adapter or disable the parameter.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.