Zero Trust Networks

Chapter 5. Trusting Devices

Trusting devices in a zero trust network is extremely critical; it’s also an exceedingly difficult problem. Devices are the battlegrounds upon which security is won or lost. Most compromises involve a malicious actor gaining access to a trusted device; and once that access is obtained, the device cannot be trusted to attest to its own security.

This chapter will discuss the many systems and processes that need to be put in place to have sufficient trust of devices deployed in the network. We will focus on the role that each of these systems plays in the larger goal of truly trusting a device. Each technology is complicated in its own right. While we can’t go into exhaustive detail on each protocol or system, we will endeavor to give enough details to help you understand the technology and avoid any potential pitfalls when using it.

We start with learning how devices gain trust in the first place.

Bootstrapping Trust

When a new device arrives, it is typically assigned an equal level of trust as that of the manufacturer and distributor. For most people, that is a fairly high level of trust (whether warranted or not). This inherited trust exists purely in meatspace though, and it is necessary to “inject” this trust into the device itself.

There are a number of ways to inject (and keep) this trust in hardware. Of course, the device ecosystem is massive, and the exact approach will differ on a case-by-case basis, but there are some basic principles ...