The number of Internet of Things (IoT) devices deployed around the world is growing at incredible speed. The primary goal of their design is optimizing their size, cost and usability, while their security is underestimated. As a consequence, they often present serious vulnerabilities, posing security threats to both individual users and organizations. For this reason, delivering software updates to these devices to patch their vulnerabilities is crucial. In this context, manufacturers face three main challenges. Firstly, the integrity of new updates must be strictly enforced to avoid the installation of malicious software, which would create more threats than it mitigates. Secondly, only efficient and lightweight protocols can be adopted, to account for the limited hardware and software resources characterizing IoT smart objects.