Cellular communication and especially mobile handsets are an essential part of our daily lives. Therefore, they need to be secure and work reliably. But mobile handsets and cellular networks are highly complex systems and securing them is a challenging task. This work takes a new path for securing mobile handsets and targets the cellular modem as the route to improve the security of mobile handsets and cellular networks. We target the modem since it is one of the essential parts of a mobile handset. The modem provides the radio link to the cellular network therefore making it a key element in...