[Cryptech Tech] arm

[Joachim Strömbergson]

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Aloha!

Fredrik Thulin wrote:
> One way of being careful is what I believe Peter G. is advocating
> here and adding an external chip with a USB host controller and a SPI
> interface, in the hopes that the SPI interface in our main MCU has
> less bugs than the USB interface in the main MCU (likely true IMHO).

One way of doing this is to actually implement that USB-SPI interface
ourself as a separate FPGA design. It could then be audited and tested
with fuzzers etc. And we would control how that HW would handle error
conditions and things we don't want. The update mechanism would simply
not be implemented for example.

We would not get the nice, USB 2.0 Sticker, but we would probably have a
good USB firewall/filter.

This could be run as a separate sub project. The deliverable is (imho)
clear. There are quite probably open cores with suitable license to
start out from.

- -- 
Med vänlig hälsning, Yours

Joachim Strömbergson - Alltid i harmonisk svängning.
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 Joachim Strömbergson          Secworks AB          joachim at secworks.se
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