Unix script security

I'm using an excellent script from R. H. Reepe for accessing accounts, but need a security line, that fits the script. Any suggestions? Thx in advance;)
Her's the script

Arg_1 = Requested Account Name (coded string)
# Arg_2 = Calling Script Name ($0)
# Arg_3 = [Calling PID (for uniqueness)]
{

_audit_log=$ORACLE_LOG/oracle_audit_trail.log
if [ "$1" = "" ]
then
echo "Error in $0 : No coded string provided"
echo "Oracle Connection Refused"
exit 1
fi
if [ "$2" = "" ]
then
echo "Error in `s_prog` : No calling script_name provided for"
echo "Subroutine s_access_account - Oracle Connection Refused"
echo "Attempt to Crack Security made by $USER at `date`" >> $_audit_log
echo "From terminal $TERM (`tty`) using script `s_prog`" >> $_audit_log
exit 2
fi
_pid=${3:-""}
_timestamp=`s_timestamp`
_script_type=`dirname $2`
_script_type=`basename $_script_type`
_script_name=`basename $2`
if [ "$_script_type" = "." ]
then
_script_type=`pwd`
_script_type=`basename $_script_type`
_script_name=`s_prog`
fi
account=`/usr/5bin/echo "$1\c" | $DECODE`
/usr/5bin/echo "export account" > $account_string"$_pid"
/usr/5bin/echo "account=$account\c" >> $account_string"$_pid"
. $account_string"$_pid"
_name=`echo "$account" | tr '/' ' ' | cut -f1-1 -d\ `
echo "$_timestamp Oracle connecting as $_name from $_script_type $_script_name" >>
$_audit_log
s_delete_account $_pid & > /dev/null 2>&1
return 0
}

what do you mean by 'security line'? Do you wish to verify that only authorized users
may invoke(run) the script?

the Oracle login will succeed or fail normally so what's your concern?

btw, there are other means to access Oracle, so this usage is marginal anyway.