PHP/Database login security

I want to send php login security to Oracle encrpted from my PHP script.

At the moment my login script looks something like below. I would like to be able to have the username and password encrypted so that if anyone did hack the webserver they still wouldn't necessarily be able to crack the database. Anyone ever done this?

$sDB = "mycompany";
$sUser = "jim";
$sPass = "triplex";

putenv("ORACLE_SID=orcl");
putenv("ORACLE_HOME=/joey/applications/oracle/product/8.0.5");

$handle = ora_plogon($sUser,$sPass) or die;