Re: Getting to consensus on packet number encryption

[Christian Huitema <[e-mail]>]

On 4/18/2018 1:09 AM, Mark Nottingham wrote:
> Thanks Christian; that's extremely helpful (and considering that I was about to embark on the same task, but do a much worse job, I'm especially appreciative).
>
> Everyone please have a read and direct your comments back here.
>
> One aspect that still hasn't been made clear AFAICT -- you say:
>
> """The process requires two passes, fetching some output of the encryption to seed the PN encryption. This is problematic for hardware implementations that typically don't buffer the output for further access."""
>
> .... and then later:
>
> """Single pass, thus mostly implementable in hardware if we assume that the PN encryption/decryption can be done in software."""
>
> Having a bit more context about the hardware implementation limitations here would be extremely helpful. Specifically, is "problematic" one of:
>
> * "More difficult for existing hardware (e.g., without firmware updates, etc.)"
> * "Impossible for existing hardware, but possible for bespoke hardware"
> * "Impossible in any hardware"
> * Prohibitively expensive for current/future hardware
> * Something else?

I tried to express the issue in my own words, based on discussions in
this list. But as I said, this is a Wiki. People with more hands-on
experience on hardware acceleration would be welcome to add a small
section describing the issue with hardware implementations.

-- Christian Huitema