Clarification of VDF FPGA Competition Judging

Dear VDF Team,

just to make sure I get it right.
I’m not quite sure about the meaning of the phrase
" The winner will be the design with the lowest latency per squaring over 1B iterations as measured by the RTL kernel driver "

What does 1B mean, just simply a single iteration ?
What is Iteration in this context ?

When looking at the command line:
host -i 1 -f 1073741824 -n 1024 -s 0x
my understanding is that simply
x^2^(2^30) mod N
is computed once (the single iteration) which however entails 2^30 modular squarings,
and the time for this whole computation is recorded and judged, not a single modular square.

For the baseline of a single modular squaring taking 50ns that would result in ~54s elapsed.

So we are interested NOT in the latency of a single modular square but in the
latency of modular square AVERAGED over MANY (here t = 2^30) iterations,
correct ?

ThanX & best regards Oliver

“1B iterations” means 2^30 (roughly one billion) repeated sequential modular squarings.

An “iteration” is a modular squaring.

Correct. (Note that you’re not required to do repeated squaring. There may be other faster ways of computing this, e.g. repeatedly take 4th powers.)

Correct :slight_smile:

Hello Justin,

yeah, of course 1B is the Billion, it all makes sense. :ghost:

Thanx & Best Regards Oliver