But you shouldn't have to install extensions to do this..

Any Windows support? YubiKey's advantage (Aswell as the fact that it's designed for keystorage, and malware can now just target Android and can automatically approve it themselves) is that it works crossplatform; I can use a YubiKey (when I can afford one) with PuTTY - there seems to be no way to do this.

We currently support Bash on Ubuntu on Windows, but PuTTY/Cygwin support is further off.

A code execution exploit on your Android phone would result in being able to approve automatically, but without Kryptonite, a trojan in _any_ of the apps on your computer could steal your SSH key and use it unhindered, like what recently happened to Handbrake [https://threatpost.com/handbrake-for-mac-compromised-with-pr...]

Outlawing Encryption? Every single person in the UK will start using Tor or similar. Want to try to ban that? Goodbye UK economy.

The issue is Theresa May doesn't understand the Internet and outlawing encryption or similar would be idiocy.

We already have Snoopers Charter, aswell as High Court-blocked websites. She's probably going to demand a UK Cert Authority that they can use for "securing" and then someone will find out the CA.

I'm surprised nobody has made something for testing; how much would it take to make something you plug a USB into and see what it does?

(I.E. "USB is typing"/"USB is doing")

There is usbpcap which captures all the packets.