Cisco VPN client .pcf file security hole

Hello,

I have a security problem with a .pcf file that Cisco VPN client uses. Being this file is easy to hack to get the password for the outside network, is there a way to mask it so that a decoder cannot reveal the password. Our vpn is thru a PIX515E firewall and if there is a way to set passwords for individual users. Any feedback will be appredciated.

Thanks

Craig Rothman 
IT/Network Administrator