What protocol does a kindle use to phone home?

Question

What protocol does a Kindle 3 WiFi use to communicate with Amazon and download files on your kindle.com/free.kindle.com account?

I know I can use some network sniffing software to find it out, but I just need a quick answer.

Answer 1

It's a standard REST protocol that is not public and is hardened to prevent non-Kindles from using it. The actual HTTP traffic is encrypted and requires multiple forms of authentication to use. Only official Kindles can make calls; everyone else is prevented using multiple techniques.