create or replace function MD5
(vpassword in varchar2)
return varchar2
is
retval varchar2(32);
begin
retval := utl_raw.cast_to_raw(dbms_obfuscation_toolkit.MD5(input_string =>lower(vpassword)));
return retval;
end;
采用Oracle的dbms_obfuscation_toolkit的加密
原文：http://www.cnblogs.com/Warmsunshine/p/5689131.html