BCD List to HEX List

[Philippe Martin]

Paul Rubin wrote:

> Philippe Martin <pmartin at snakecard.com> writes:
>> On device #1 no constraint for my purpose. On the smartcard, the tradeoff
>> is between using EEPROM (plenty + slow + small life expectancy) for temp
>> variables versus RAM (very little) ... but I do not think it is an issue
>> eather in my case. Speed is what worries me most (crypto takes time).
> 
> You should not have to do this decimal-hex conversion repeatedly in a
> crypto operation.  Do you have a public-key accelerator (or MAC unit)
> on that cpu?  Do you really care about speed?  I had thought up a cute
> O(n**3) scheme that might have been ok for 8 digits but probably not
> for 24.

I did not explain myself correctly, the "decimal" operations are done in
"clear mode" as they are made within the cards which by definition cannot
be broken, requests and results that go to/from the devices are
encrypted/signed with diversified keys ... but that another story ;-)

Regards,

Philippe