For brevity in this article I use the term “Ethereum”, however this applies to all systems based on the “preDao Ethereum Prime” that spawned ETH, ETC, EXP, ELLA, and many other versions.
Process this before proceeding:
Ethereum was never ASIC proof and it is no longer ASIC resistant.
Asics for ethhash are here. They are currently and have likely been here for some time and are mining on the public chains. They are much cheaper and energy efficient than current GPU mining rigs and are only available from one source. Their construction is not opensource and no one outside of their manufacturing chain knows how they work, how they process data, or anything about them outside of what has been publicly announced by Bitmain.
Understanding the incentive model for ASIC production requires no knowledge of cryptographic hashing or wonky block chain minutia. Mining is a for profit business. Their profit is a product of their revenue minus variable costs and fixed costs. If they can lower their costs they profit more. Asics are more efficient per mh/s on electric, cheaper, and smaller, offer a clear advantage over current GPU mining rigs.
ASIC resistance is not ASIC proof
How did we get here? Why was Ethereum designed to be ASIC resistant? How was Ethereum ASIC resistant for so long?
A long time ago in a blockchain long forgotten, Ethereum was meant to use Proof of Work until the magical system of PoS was implemented back in 2016. Design and technical debt was added to the system in the form of a difficulty bomb and an ever-increasing DAG to ensure this utopian dream would happen. Both were “temporary” and intended to deter large capital investment in Ethereum mining. Both were poorly thought out for long term sustainment. The difficulty bomb has been removed by both main chains of Ethereum now as it was unproductive and more harmful than necessary. Good riddance. The DAG is something not often discussed outside of mining. The DAG is the property of the ethHash mining function that creates a need for an ever-increasing amount of memory. Memory, being very expensive to add to an ASIC, has been the limiting factor thus far in resistance. The DAG began at 1GB and is currently ~ 2.4 depending on which chain you are mining on. If you have purchased any GPU in the last 18 months you will have noticed a steep price increase at the 4gb size as these are the only cards that are now capable of handling the DAG. Any GPU card or ASIC with less than 3GB( good until April 2019) is unable to meet the current memory requirements to mine. This limits mining to high end cards and, now, ASICS. This constant DAG growth will eventually lead to a broader discussion about bus sizes/speed and memory constraints on consumer grade GPUS, but that is for another post.
For a more in depth dive into the DAG and size calculator check out: https://investoon.com/tools/dag_size
How to effectively combat an ASICS without knowing anything about their design.
Reset the DAG to its initial 1gb state.
There is no step 2
Resetting the DAG to its initial state and letting it grow retains all the proprieties of ASIC resistance that have always been afforded by making ASICS non competitive on the metric of accessibility. This action would allow nearly every GPU on the planet the ability to mine, while still ensuring it is non trivial to construct ASICS. The hobbyist miners will be given a method of combating centralized ASIC miners thus allowing the community to help themselves by dusting off their old cards and rocking out.
The alternative of doing nothing and really hoping PoS comes or moving goal posts ever 6 months with new algorithms are both incredibly risky and “forky” solutions. Resetting the dag is trivial code wise and great for everyone. Unless you just spent a ton of money developing ASICs.