
Low latency multipliers and cryptographic puzzles - jsnell
https://blog.janestreet.com/really-low-latency-multipliers-and-cryptographic-puzzles/
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phkahler
Interesting that the estimated date for solving the puzzle was based on
Moore's law. There's an implicit assumption that nobody will factor the
modulus before then.

RSA is as solid as ever.

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layoutIfNeeded
_> There were no magic tricks in his approach. It was just that Rivest’s
original estimate was off by a factor of ten. While we don’t have 10GHz CPUs
sitting in our desktops (mainly due to thermal issues), CPU and multi-core
architecture has advanced dramatically._

Ummm, how exactly does multicore help solving this puzzle? It was designed
specifically to be un-parallelizable.

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gwern
IIRC, while they couldn't cheat the need for squarings, each
squaring/multiplication itself has some internal parallelism which can be
exploited, and GMP does some of that, and the Cryptophage team took that even
further in conjunction with their exotic hardware. So the serial step could be
accelerated more than Rivest predicted.

~~~
layoutIfNeeded
Sure, but that still has nothing to do with multiple CPU cores.

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vertak
This was a good read about an area of computing I’ve only heard about in
passing (specifically crypto miner design). But it was definitely over my head
as someone who has never had to work with FPGAs.

Can anyone suggest a good online course, textbook, or article to get started
understanding and working (via some simulation software so it’s cheap!) on
FPGAs?

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nuclearnice1
See [https://github.com/aws/aws-
fpga/blob/master/README.md#gettin...](https://github.com/aws/aws-
fpga/blob/master/README.md#gettingstarted)

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tgflynn
I wonder how competitive GPU's would be with FPGA's on this type of problem.

FPGA's have the advantage that the circuit architecture can be designed
specifically for the algorithm but as far as I know they have much lower gate
density and clock speeds compared to top of the line GPU's.

In the case of bitcoin mining as far as I know GPU's passed the hat directly
to ASIC's. I never heard that FPGA's were competitive for that.

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blattimwind
> In the case of bitcoin mining as far as I know GPU's passed the hat directly
> to ASIC's. I never heard that FPGA's were competitive for that.

They were, before the ASICs came. CPU -> GPU -> FPGA -> ASIC. A classic story
of specialization.

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Taek
Ehhh not really. There was some FPGA mining that happened in Bitcoin but it
was always niche rather than at-scale.

FPGAs are a lot better than GPUs from the perspective of energy efficiency,
but the FPGAs themselves are very expensive to purchase, and are a lot more
specialized than GPUs. ASICs showed up before FGPAs ever really took off, and
even if ASICs hadn't showed up it's not clear that FGPAs would have been
superior on a total-cost basis to GPUs except in niche circumstances.

~~~
tgflynn
> are a lot more specialized than GPUs.

What do you mean by "more specialized" ? FPGA's can implement any logic
circuit whereas GPU's are optimized for highly parallel arithmetic
computations. I don't understand how that makes FPGA's "more specialized". It
seems like they are in fact more general.

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wmf
You can't buy FPGAs at Fry's and you can't use them for gaming when you're not
mining.

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karmakatze
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I wonder what this means? Is there a timer until the cookie gets set?

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aspenmayer
Good point. It wasn’t immediately obvious that your first part was a quote
from the site, but you’re right that it’s unclear. I don’t see how this could
possibly be GDPR compliant.

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oh_sigh
Does the blog of a NYC-based trading company need to be GDPR compliant? They
don't offer goods or services to EU residents AFAICT.

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occamrazor
I guess Jane Street has customers in the EU. It is likely that occasionally
they meet them in the EU. This might be sufficient to consider them as doing
business in the EU, and submitting them to the GDPR.

