[Oracle] To generate a random value in hexa string

@see on : http://www.akadia.com/services/ora_important_part_4.html#Loading%20Data%20using%20External%20Tables

CREATE OR REPLACE FUNCTION secure_rand
        RETURN VARCHAR2 IS
           seedval RAW(80) := HEXTORAW('72DD046BF9892A3544B7587475FDF5A0'                                
        || 'B8F6C44F5C33B57C8156E5CBE92A8477'                                   
        || 'F4F8FCDE5A21236CA1D7938C4D5E47A8'                                 
        || 'D7BBC407DB6DB8EB7695BA5565218C4F'                                   
        || 'D66D5C41523FDCBA8D92CDBD8DC75C54');
        BEGIN
          RETURN RAWTOHEX(DBMS_OBFUSCATION_TOOLKIT.DES3GETKEY(seed => seedval));
        END;