Announcing Zcash Blossom and proposed feature goals

It’s about control over the BCH protocol. (off topic)

On topic: Super excited about these changes and the potential PoW change! :zebra::zebra::zebra:

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We’re interested in PoS and it’s certainly a candidate for research in 2019. However we can’t safely commit to activating it in 2019. Meanwhile, we’ll be investigating other 51% protections.

Please don’t disparage a poorly defined set of people (even with the qualifier). There are no “BCH people”. We’re all just people who happen to be drawn to different communities or tech based on a variety of reasons.

I haven’t followed the BCH issue at all, yet it’s quite clear to me that community splits don’t need to have anything to do with technical decisions, and could be entirely social. And furthermore, the entirely non-technical social issues are crucially important.

In any case, if anyone (regardless of their motivations) attempts 51% attacks on Zcash, we should anticipate and protect against that as far as possible with technical measures as well as community coordination.

We should strive to avoid cult-thinking from infecting Zcash community.


Yes! We’ve started conversations directly between Ayo and the Company.

Aside from the exciting strategic motivations and new possible use cases, we’re getting practice in collaborating with non-Zcash Company teams on Blossom, even before we’ve transitioned to a fully open Foundation facilitated development process.


As always I appreciate your skeptical but civil input. You may turn out to be right! Let’s put a note on our calendars to revisit this question in a year. :slightly_smiling_face:


Thanks for clarifying. I’ll keep watching the market for GPU ROI metrics as 2019 proceeds.

My current belief is that the worst case scenario would be that the exact same entities dominate both algorithms. In that case, the result would be similar to if we made no change with some curious differences.

First, those entities would have more GPU capital outlay in the Harmony Mining case versus the “do nothing case”. GPUs are more versatile and easier to acquire, so this means those entities can migrate to a different GPU coin if the market dynamics shift enough. It also means they are subject to more competition at least on the equipment front, IMO, because it’s easier to acquire GPUs around the world. (Presumably, though, the reason they dominate is because they have energy cost advantages, correct? Those will not be affected by any PoW change.)

So I see both a benefit (easier entry for new competitors in terms of capital outlay) and a drawback (less “loyalty” to Zcash due to low cost to repurpose GPUs to an alternative).

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I propose that people who opt-in to mining the new algorithm receive time-locked coins. Currently the coinbase for finding a block is 10 ZEC that is time-locked for 100 blocks. I propose that for blocks found with the new algorithm, it would instead be 50 timelocked utxos worth 0.2 ZEC each, and each one timelocked for 4000 blocks longer than the previous one.

That way, every miner choosing to mine the new algorithm would be a long-term investor in the value of ZEC and would have an economic incentive to protect the network, regardless of whether they were mining with ASIC, GPU, CPU, or something else.

This addresses the issue of “loyalty” that you mentioned in your comment.


By Succinct Blockchains, do you mean using proving systems with size or time compression to lower the cost/bandwidth for full validation nodes?

My belief is that is substantially more complex than Harmony Mining. What we call Harmony Mining already has many precedents, some quite old (the oldest known to me is MyriadCoin), that have been running in production. The proving system scalability area is brand new, with no production launched instances (although Coda is close, with a testnet and open source, IIUC).

Doing that well requires plenty of attention from a very small class of experts (a good chunk of which work at ZcashCo, so that definitely helps).

Anyway, to repeat myself, this is definitely an area of interest we are looking into and may become a goal for future post-Blossom upgrades.

Edit: Added reference to MyriadCoin to document my main prior work reference.


The purpose of coinbase maturity (of 100 blocks) is to help prevent double-spends from block reorgs, it’s not related to economic incentive or loyalty.

Today, miners can spend after 4 hours. To lock up the mining reward for 7 days (4000 blocks) would expose miners to increased risk of market volatility as well as opportunity cost, therefore the miner receives less than what they actually earned i.e. the present value of future cash flow. This could end up centralizing mining into ever fewer hands as only well-financed entities would be able to manage the risk of future payments (without interest).


Right now, at the monent, an ETH miner gets around ~0.20$/day with 1x 1080ti GPU (after electricity). That’s below USD100 per year. I guess that 2nd hand 1080ti’s are available for around USD 500-600, means 5+ years for gpu roi …

Actually this isn’t the biggest problem. The problem is that once ETH goes POS there will be 222.71 Th/s gpu hashpower released for switching to other coins and algos. Have in mind that until than more and more coins switch to POS as well. This hashpower from ETH can’t be handled by any coin or algo, neither all together can handle it as they are allraedy now at the current price at their limits to stay with some cents profitable.

Times are changing. Daily there is more and more new hardware (gpu/asic) added on POW with less and less price increase. POW doesn’t work out anymore for private & personal home miners with average electricity. I would go as far as saying that every POW miner with above USD 0.05 kw/h has to quiet the next 12 months, latest.

Sure, there are a lot of miners hoping for another miracle like Dec 17/Jan 18 but i’am not one that believes in miracles, lol.

In my opinion, the haromony upgrade comes 1 1/2 year to late for us smaller/mid miners. I personally have no problem with it as i quieted buying hardware and investing into POW allready and mostly will stop mining in the next 3 months, pretty sure others will follow after new year and the missing miracle, lol.

Means again, just to underline it and to make a notice in the calendar for 15.Nov.2019:

  • Private ZEC Asic miners will stop mining in latest 12 months
  • Private POW gpu mining will end all over at the time ETH switches to POS, i guess again in latest 12 months, maybe sooner.
  • Due less and less miners active ZEC wallets will be even less than now. They dropped from 90+k to below 30k in the last months.
  • ZEC will lose ground to it’s direct competitors coming late with POS …

Curious where you got this “number of active Zcash wallets” statistic from @boxalex ?

Price speculation (scroll up a little bit, can’t figure out how to link it!)

Link: Price Speculation

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I added the link to @Lisfin post, but still not clear where the information is from. If accurate, these are interesting numbers that Zooko and Nathan should take into account when thinking about PoW.


Looks like,1550417353149.4604
Compared to others it really doesnt look out of the norm (other than that it hung in there longer than others)

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Your reply instills great confidence. There is a lot of fear, whether it is justified or not, doesn’t diminish it’s importance. Resistance to any attack will be seen as yet another big plus for zcash. I am very glad to find the zcash team is taking it seriously. Please keep us informed on this matter as things progress.

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June 25th is the day I received my batch 1 mini’s. It looks like that is the day it started going down. It could be a sign of centralization since all the hobbyist miners quit mining and the pools needed to pay less people.

Love the name, love the roadmap.

Harmony mining is a nice concept but I share same concerns as @boxalex: PoW is pratically done for and when ETH fully switches to PoS there will be no coin that can sustain such hashrate. Also to put in consideration is FPGA mining, which, with the right monetary incentive, could crush one side of the chain and just switch asic vs gpu discussion to fpga vs gpu…

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Yesterday i was in the mood of looking up graphs,charts and stats for ZEC and posted allready part of it from various analytic websites that look more than reliable. I posted them in the price speculation thread, but i think i will make a seperate thread with maybe montly updated charts, graphs and stats about ZEC as there are really interesting ones, even more when directly compared to other coins and competition…


+1, totally forgot about the FPGA issue, the next thing that will hit gpu’s hard. The next “milestone” in gpu POW being practically done we will witness is the ETH constantinople upgrade lowering the POW rewards. This will allready put out all miners with electricity costs about a certain level, easy and simple as that …

Have in mind that even currently miners Asic/GPU’s in a lot of countries aren’t able to mine due higher electricity costs, take Germany as an example ~0.33$ per kw/h. Other western countries like Spain, UK, Italy, France and many others have very high electricity costs as well. Practically POW is forcing out currently miners from these countries first, just logical, the more you pay for electricity, the sooner you get forced out.

The only logical, fair decision would have been a POS or POS like design, maybe temporary a hybrid design POW/POS to counter the centralization effect (+ gaining many more advantages) and to abandon a doomed to fail approach, POW.


this is an absolutely stupid decision

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Dont even waste time on harmony mining. Switch to a hybrid POW/POS model and everyone would rejoice. Maybe POS incentives for running a node.

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