[Cryptography] Kindle as crypto hardware

[Bill Stewart]

At 08:19 AM 12/4/2013, you wrote:
>On Wed, Dec 4, 2013 at 11:02 AM, Theodore Ts'o 
><<mailto:tytso at mit.edu>tytso at mit.edu> wrote:
>On Wed, Dec 04, 2013 at 10:40:25AM -0500, Phillip Hallam-Baker wrote:
>(BTW, my quick pricing of a Rasberry Pi with a display is not cheaper
>than an Arduino, but your milage may vary.)
>The Pi has HDMI out so it can hook into an existing display so 
>depending on the application it is a wash. It also has the random 
>number generator and the operating system boots from SD card which I 
>find more comforting than loading up a black box via USB.

HDMI means you can plug the Pi into a newer television or monitor, if 
you're not paranoid about those, and you can plug in a vanilla USB keyboard.
There isn't persistent memory on the board; the OS is installed on a 
removable SD flash card, so if you need to shred anything it's the $5 flash.

As much as I like the Arduino for controlling blinky-lights and 
thermostats, it's not the platform you want to use for number-crunching.
It's an 8-bit CPU running at 20 MHz, so generating ECC keys will take 
unacceptably long.  Spend the extra $10 for the Pi, which is at least 
a 700 MHz 32-bit chip.  And don't go buying that NSArrduino clone 
board, which has a chip marked "ATmega328" that's actually an ARM 
emulation with a radio transmitter.

Both CPUs are under $5, and if you're willing to use a serial 
display, you could get one of the few PDIP ARM chips so you can plug 
the chip into a socket and have nothing with memory in it remaining 
on the board.

But it's probably safe enough and a lot less labor to just get a 
cheap phone or Kindle that already has all the parts.