store encypted passwords

Hello, I have set up FreeRADIUS Version 2.1.10 on an Ubuntu server 12.04, Mysql Server version: 5.5.24. Everything is up and running but the users passwords are stored in plain text in raddacct. I tried changing the attribute to Crypt-Password but it doesn't change anything. Do I need to make a change to a config file also? Not sure what type of encryption would be best one that works MD5? Thanks,