[Cryptography] [FORGED] Re: USB 3.0 authentication: market power and DRM?

[Philipp Gühring]

Hi,

> One genuine reason, although it's not clear that the auth achieves it,
> is to
> prevent problems due to cables that lie about their capabilities.  The
> typical
> USB cable is 28 AWG, which can't carry anywhere near the power that USB
> 3
> power delivery is rated for [...]

I agree with that problem, but it seems to me that this spec will not
help, since it does end-to-end authentication, but you have a
cable-in-the-middle problem. So you have to authenticate the whole chain,
and I currently do not see any technology that could do that.

Perhaps a slow start mechanism like TCP would be a better idea (to ramp up
the power slowly), and to measure the temperature of the cable all the time.

Best regards,
Philipp