Turn on AP encryption and Setup Wifi DHCP Service:

nano setencryptiondhcp.sh
#!/bin/sh
/sbin/uci set wireless.@wifi-iface[0].mode=ap
/sbin/uci set wireless.@wifi-iface[0].ssid=Yun
/sbin/uci set wireless.@wifi-iface[0].encryption=psk-mixed
/sbin/uci set wireless.@wifi-iface[0].key=password
/sbin/uci commit wireless
wifi down; wifi up
/sbin/uci set dhcp.lan.start=100
/sbin/uci set dhcp.lan.limit=150
/sbin/uci set dhcp.lan.leasetime=6h
/sbin/uci set dhcp.lan.ignore=0
/sbin/uci commit dhcp
/etc/init.d/network restart
/etc/init.d/dnsmasq reload
/bin/ash setencryptiondhcp.sh