U2F and nRF52840

[Jeremy Drake]

>> If not, how (in)compatible is the current code with a possible U2F/UAF
>> implementation?
>
> Crypto routines can be reused.  The USB protocol, CCID, is same.  (CCID
> protocol is the protocol of card reader.)  Application layer is
> different.

Is it?  I haven't looked too closely, but I was under the impression that 
U2F was implemented as a HID device rather than CCID/"smartcard".