9$ CHIP computer

[Larz60+]

As are 95% of HTTPS servers.

With companies like Let's Encrypt offering free certificates and automated management tools, it is also easier than ever to deploy an HTTPS website that will be trusted by all modern browsers.

Have to use something like Strict-Transport-Security

There are several papers available on the subject:
Detecting Man-in-the-Middle and Wormhole Attacks in Wireless Mesh Networks
Security Issues in Wireless Mesh Networks

Accountability for wireless LANs, ad hoc networks, and wireless mesh networks
Book - Security of Self-Organizing Networks

and a lot more

Since I love to read, I'll start with these.

It may end up being more than I want to take on, but so far I'm still interested.