Necleus is a smart lock based on IoT built on Arduino uno and Ethernet shield. It can be accessed by a key and internet through software interface built in java. He's used an I2C EEPROM as key which hardly costs 15 cents resulting in an inexpensive key.
This project is for home alarm internet dialer.
Have the alarm system email you if the alarm has gone off and ability to contact the panel and set/unset/view logs using any browser from anywhere(ex.smart phone)