In this chapter, we touched on the enormously large and complex world of applied cryptography, cryptographic modules, key management, cryptographic application in IoT protocols, and possible future looks into cryptographic enablement of distributed IoT trust in the form of blockchain technology.
Perhaps the most important message of this chapter is to take cryptography and its methods of implementation seriously. Many IoT devices and service companies simply do not come from a heritage of building secure cryptographic systems and it is unwise to consider a vendor's hyper-marketed claims that their "256 bit AES" is secure. There are just too many ways to thwart cryptography if not properly implemented.
In the next chapter, we will dive into identity and access management (IAM) for the IoT.