Bitcoin Forum

Hello!

BitMonero is a new CryptoNote-based currency we have started a week ago. In this post I'll explain what is a merged mining and why I consider it as a good feature.

Merged mining is the way to use hashpower from one blockchain in several other blockchain. MM happens between two blockchains:

- a "donor" blockchain knows nothing about MM
- a "merge mining" blockchain is able to accept PoW from "donor" blockchain. Several "merge mining" blockchain can use work from "donor" blockchain at the same time (on same mining machine).

Main facts about merged mining

1. From the network's point of view MM saves energy because we use same work for several blockchains.

2. From miner's point of view MM gives additional coins to miners.

3. MM increase hashpower of all chains involved because some miners will switch from one-chain mining to MM.

Merged mining algorithm

Let's suppose we have a "donor" blockchain AAA and two "merged mining" blockchains XXX and ZZZ. As it is stated above AAA doesn't know anything about merged mining. XXX and ZZZ have to support it explicitely. Non-merged miner will mine each chain separately. Merged miners will do following actions:

1. Create block templates for XXX and ZZZ: blkXXX and blkZZZ
2. Create block template for AAA that includes references to blkXXX and blkZZZ. References are stored in coinbases because there is no suitable location in block header.
3. Mine block blkAAA:
3.1 Calculate hash for blkAAA (we don't need to calculate hash directly for "merged mining" chains as soon as they can accept PoW from "donor")
3.2 Compare hash with difficulty for AAA, XXX and ZZZ.
3.3 Submit block to corresponding network if difficulty is sufficient
3.4 Go to 3.1

Miners are free to choose any "donor" blockchain and any set of "merged mining" chains they want to support. A number of mining configurations is possible:

1. One chain mining

2. One "donor" + one "merged mining"

3. One "donor" + several "merged mining"

4. Fake "donor" + several "merged mining"

The number of "merged mining" chains miner can support at the same time isn't limited directly. As soon as at least one difficilty target is met miner can send a block to corresponing network. But there is always only one "donor" chain at the same time: each miner has to choose his own "donor" chain or use fake "donor" for mining. Fake donor means that you really don't mine any "donor" chain but only mine several "merged mining" chains together. Configuration with two donor chains isn't possible.

"Donor" chain can have more or less hashpower than "merged mining". Relative hashrate isn't important for merged mining: "donor" chain can have less hashrate that "merged mining" one. "Merged mining" network accumulates hashrate from both "donor" chain and from all other "merged mining" chains with same PoW. "Donor" chain can't use PoW from other networks directly.

Bytecoin and BitMonero merged mining

In out case BCN is a "donor" blockchain. No code changes will be implemented in BCN.

BMR can be a "merged mining" chain. In case it will accept PoW from BCN or from any other "donor" or "merged mining" blockchain with CryptoNight PoW.

In case of merged mining available each miner can choose

- to use or not to use "donor" chain
- the specfific "donor" chain to use
- the number or "merged mining" chains to support

This way nobody will loose from merged mining with such an implementation.

Action plan

Merged mining needs a hardfork: all users are to update their damons. We can't do such changes ourselves. We are asking miners to state their opinions. How to express your opinion:

- if you don't want "merged mining" in BitMonero you don't have to do anything
- if you want "merged mining" in Bitmonero you have to update yout mining daemon now. New mining daemon will issue blocks with an incremented minor_version field. In case > 75% of blocks mined will have an incremented minor_version we will accept "merged minng" and new code will be published on git.

Calculations will be perfromed on 29 April. 750 blocks with incremented minor_version from last 1000 are required to switch for merged mining.

Here is a "voting for merged mining" daemon for Windows:
https://mega.co.nz/#!ogxTXIBJ!GeAuLXWLM-YAF41ylfn2w14ZTUovRehicrevIIAph9Q

For Linux you need to build it yourself.

For what it's worth I really don't think Monero needs merged mining and strongly discourage others from following through with this. Monero can stand on its own as the first freely-distributed Cryptonote currency and doesn't need to be tied to Bytecoin, which is more than 80% mined already. Why bother affiliating with another coin when Monero has already seen huge increases in hash in only one week of mining? If a botnet hadn't jumped on Bytecoin Monero was already on track to surpass its net hash.

+1

Please make sure that the "updated" version requires the miner to actually take some action to vote (such as a config option). Having people who simply download and use the latest version automatically and invisibly vote in favor by default makes this concept of voting into a sham.

As I have said on other threads, the idea that you can merge mine or not at your choice and no one loses from having merge mining implemented if they don't want to do it is false. The difficulties will adjust so that those who don't merge mine will get less and everyone is forced to mine both chains to compete.

It is also a myth that it reduces energy usage. People mining one or the other will just mine both, energy usage remains the same. It also does not give additional coins. Again more miners on both chains means the difficulty goes up. Coins awarded remains the same.

I'm very disappointed that TFT is using false arguments like energy savings or more coins to advance this agenda.

I also dont want merge mining with bytecoin. I think its better for monero to stay away from 80% premined bytecoin.

Ditto

Ok. That's right. I will fix this before making any calculations.

Thank you.

As far as I got TFT, he got valid points.

It does save your energy and let's efficiently mine two coins with no extra effort. Given the current exchange rate of BCN, I think it might still be a good idea to get twice the income with the same effort.

At least, it's from my perspective, I might be wrong.

The actual life and miners' behavior is not rigid math, so we can't actually prove the theoretical proposition about merged mining unless we give it shot. My point is, I'd better mine two coins instead of one. Where am I wrong exactly?

Well, it’s not exactly “twice the income” but it’s still an income.


But you will gain the reward from both chains, aren’t you?  I don’t understand it fully but from my side mining 2 chains is better than mining 1. Even if the difficulty is going up.

So, currently I support MM implementation.

Not its exactly the same, since each chain has a fixed reward schedule. No more coins are being given out. Let's say hypothetically (because it makes the calculation simpler but does not change the result) that half the people are mining bytecoin and half are mining monero. So half are getting the bytecoins and half are getting the monero coins.

After merged mining, assuming both coins retain significant value, everyone will mine both, the difficulty of each will double, and everyone will get half the coins on the chain they were mining before, plus half of the other coins form the other chain.

There are no free coins here. Where would they come from, since the reward output in both chains is fixed?

You're ignoring that the difficulty of both coins will go up because nearly everyone will be mining both instead of choosing between one or the other. Yes, you will get two coins, but you will get half as many of each.

Likewise, if you mine anything at all with your computer or computers, the energy usage is the same. It doesn't matter if you mine one coin at lower difficulty or two coins at higher difficulty. Same energy usage, same output.

But the block you found is going to the both chains. That’s the main cause of merged mining to me.

Also, difficulty won't go up this drastically - you're assuming that with double difficulty the reward will be cut in half but it won't.
According to the bytecoin.org:
Block reward decreases each block according to the formula:
BaseReward = (MSupply - A)/218
where MSupply = (264 - 1) atomic units and 'A' is amount of already generated coins;

Reward will decrease, yes, but not that hard. I'm not that good at math but I think slightly lower reward from both coins simultaneously is better then current reward from 1.

Exactly, but you will find fewer blocks (higher difficulty).


I was only assuming double because that makes the calculation and illustration easier. If you work it out with actual hash rate numbers you get the same result -- some coins on each chain, but fewer of each.

You can already get some coins on each chain if you want, just mine with one computer on each chain, or if you only have one computer, switch off between them.

There is no free lunch. If you can mine both, so can everybody else, and the difficulty must go up.

the same situation was with the namecoin, isn't it? what was the outcome ?

The outcome was that the namecoin difficulty shot up my an enormous amount. Namecoin was easily solo mineable before merged mining went in. I know this because I mined namecoin before the merge. After the merger, it was not.

I tried to find a chart showing namecoin difficulty from way back then (2011), but I couldn't. Bitcoin difficulty probably also increased a little on the margin, since people previously mining namecoin instead of bitcoin switched over to mining both, although namecoin was so much smaller than bitcoin this effect was likely negligible.

What do I do to vote?  Linux

If you want to vote against, do nothing and do not upgrade your nodes.

If you want to vote for, you can perhaps just upgrade to the current version from github, although TFT said he would be changing it to require some explicit action to vote, instead of treating everyone who newly downloads or upgrades as voting "for" by default.

OK thanks.  Then I do nothing.  Where is updated code for linux compile?  I don't see.

Precompiled? I'm not sure. I always build my own.

I always compile also.  Just not see any update on github to source.

Look in commits

I've implemented merged mining code for BitMonero (I work with thankful_for_today). I see that community is against MM and I will start my own currency based on CryptoNote/BitMonero with merged mining: https://bitcointalk.org/index.php?topic=585611.0

Just for everyone to be sure,

if you retrieved the source code from github lately and compiled it, you are automatically voting for merged mining.  You can tell by looking at cryptonote_config.h in /src/

SUPPORT merged mining:

AGAINST merged mining:

That's right. Results will be calculated starting from the moment an explicit voting option will be provided.

I don't know why people set aggressive towards MM

I doubt namecoin is good example to compare with.
 As it was told Namecoin was smaller in compare with Bitcoin and the result was not visible

BitMonero, on the contrary, has already great increases in number of miners.
I support idea of MM as there is a possibility to different way of evolution for both coins just because of their different features.
As far as I know, BitMonero has shorter block time which make this coin make faster transactions and  that causes differentiation in finding another block - so the chance of finding new block in both chains is becoming more unpredictable. And no need to mention that mining reward from two coins is better then reward from one coin.

IMHO, the point is if you can get more reward without extra effort when why not to get additional reward?

If I miss the point - could you please tell me what exactly is wrong about MM?

As a trader I only support merged mining as if this would increase the amount of coins when there would be rather more people willing to join mining and you and I would have more coins to exchange on BTC.

I see what people are trying to tell here - that there is no reason for doing this, that there is no profit as it's gonna be the same situation (no saving energy, no extra reward) , but if it doesn't heart when why shall be against it?

I would vote for MM ! I encourage you to support MM!

Merged mining is basically a freeroll since it won't need more resource.

Maybe I get it wrong but, IMO, MM help to use already found block to find block in another coin, which means that your chance to find blocks in both is a lit bit increasing.

What to do in case I have Linux ? As far as I understood there is no Linux ver which support merged mining, am I right?
I am not a programmer and not capable to create binaries

there is a How-To thread with the linux compile instructions: https://bitcointalk.org/index.php?topic=544715.0

in order to vote for the mm you will have to compile newest version.

Let me explain this with a simple example (we consider the blocktime is the same for each chain):

Let's say there is 20 peoples mining with the same hardware
They are mining for the duration of 40 blocks.
So 40 blocks of Bytecoin will be produced (noted : BytecoinB)
So 40 blocks of Monero will be produced (noted : MoneroB)

- Without Merged Mining (current situation):
 10 people are mining Bytecoin
 10 people are mining Monero

 On average, for 40 block in the blockchain, each user will get 4 blocks of the chain he mine (40/10).
 So :
 10 people get 4 BytecoinB
 10 people get 4 MoneroB

- With Merged Mining :
 20 people are merged mining Bytecoin and Monero

 On average, for 40 block in the blockchain, each user will get 2 blocks of each chain (40/20).
 So :
 20 people get 2 BytecoinB
 20 people get 2 MoneroB

- Conlusion :
Without Merged mining, you can chose to have either 4 BytecoinB or 4 MoneroB.
With Merged mining, you will have 2 BytecoinB and 2 MoneroB.

- Side note :
With this example it's easy to understand why (if you are a rational economic agent) you don't have the choice to not do merged mining if its available (you will just lose 2 BytecoinB).

So if you think Bytecoin was ninja mined and you don't want to validate that with your hash power, you better not want merged mining to be implemented in Monero.

SlyWax.

Great analysis and example SlyWax. I would add that without merged mining in your example you still have the choice to get 2 BytecoinB and 2 MoneroB, just mine each one for half the time, and that's what you get. If you have two miners, split them up, otherwise mine one coin for an hour and then switch to the other coin for an hour.  

Merged mining gives no additional choice, it only takes away a choice, as you explained above.

I think, it’s a good idea. BCN has fairly stable exchange rate, moreover we solve 2 problems. First is the fear of closed community and the second one is the fear of new coin with untrusted (now) algorithm (MRO has no normal course or clear system of work).

It’s no difference for our computing power to receive MRO or MRO + BCN. Don’t forget, that we are talking about money and this option will brings a real benefit for us. So, why should we abandon this function?

And if the problem is in "policy" and developers disagreements, then why miners have to suffer?

Does that mean that the blkAAA will be put in the blockchain of coin XXX ?

If yes that’s a problem space wise, if no how do you check it's correct ?

how come BCN has a fairly stable exchange rate? It is not listed anywhere. There are buy orders listed on the thread that noone actually responds. BCN preminers just seem to unloading the premine...

As for the difference read the whole thread. IF we merge mine we MUST also mine BCN. And with all that premine BCN is useless...

i posted this on bmr emmision curve thread. i apologize for double post but i am  eager to getting input

 would it be better to leave this coin alone. It seems it is now Fractured.
If coin continues then so be it. Let miners cont to mine coin as is.
Honey penny for example is building on BCN. There are a a lot of individual that are very Knowledgeable. could this coin be developed to include private messaging, Proof of work, and proof of stake. Perhaps, other mechanism Duration of mining. This to encourage mining in The distant future.add colored coins ability. Just a thought. I realize this maybe stupid.
I don't see necessity to fund project. Developers wold be among Earliest adopters. If it is a great Idea than it will Succeed. If you build it the Miners will Come. And so the more users the greater the Demand-the higher the price of original coins.. Compared to those mining from the very first hour, Knowledge coupled with low difficulty they probably have more coins than I do I started Mining monero 5 days After launch and so far  have accumulated 260 coins. i am speculating but likely tft has more coins than i do and well deserved

I am against merged mining.

I am not in favour of merged mining. Keep Monero separate from ByteCoin for a 'new' clean image from the start. We don't want 'baggage'!  

Well said brother. This coin has a compelling technology, great name, a clean launch, a strong respect for fairness, and an amazing team of people. The best path forward is to focus on our strengths and not have anything to do with "that other coin" or even mention it, much less merge mine it. Leave the baggage behind.

Everything about this coin is so far superior to the botched effort that came before, it is remarkable we are even having this conversation.

shit, I already tried to compile with 1 OR 0 ... ( Ubuntu universe ) both went to tank on my hardware :-/

How will the votes be calculated? By the hash power or by number of miner?

I oppose merged mining.

I already set it 0 but cant compile the code .. sounds like loopless programming ...

https://bitcointalk.org/index.php?topic=582670.0

Seems we have a bifurcation point now as There are two proposed protocol changes

Being asked to express my opinion, IMO that MM has either good and bad perspective cause as long as we discuss it the diff in BCN is growing and chance to MM is disappearing. I believe, MM is better choice as no wonder but mining two coins at the same time (even with less reward) is a way of hedging.

As for second possible change, I wrote my view on the relevant thread  - https://bitcointalk.org/index.php?topic=585480.0

I don't understand why the chance is disappearing. It could always be added later, right?

Namecoin was around for quite a while before it was merge mined with bitcoin, much more than a week or two.

I don't see any urgency at all.

Agree with smooth, there is no need to hurry up with such important decisions.
Nice to see TFT care about our opinions.

Excuse me, didn't get it how exactly votes would be implemented?

btw, wanted to vote for bitmonero at comkort.com but couldn't find it  :(

I am not in favour of merged mining.

I traded BCN, smooth traded BCN and more... Exchange thread is active https://bitcointalk.org/index.php?topic=531925.180. It's mine that BCN has fairly stable exchange rate IMO.

Everyone doesn't use original arguments, of course.

Indeed, we build an opinion on its own philosophy and put different things in priority.
IMO, trading activity confirm Bytecoin to be stable.

btw, BCN was not premined, that's the conclusion I recently came too.
No doubt it's better to blame 'premining' on the fact that you're too late to join mining it.

lol. I would like to ask just for the lolz how did you come up with your recet conclusion!

I would ask how it is that this army of 1000 (or is it 100 billion) Newbies always show up and argue every issue in favor of helping BCN. Why would that be?

sorry, my mistake, have less info.
No i get where is no urgency indeed.

Y'all know sometimes when something new is coming you have a hope it's for better.
I see I need more time to get it right

What's the deadline to sum up with calculations? When we gonna know what the majority have decided ?

No need of mergemining Monero

Bytecoin was stealth mined, no need doing anything with it

same on the other hand, IMHO.

I know that smooth doesn't have alt newbies but everything is seen clearly.
 

Actually voting is closed now as soon as nearly nobody wants merge mining in BMR. Let's talk about this again later in case opinion will change.

You make a valid point. Forum polls are pretty hard to trust at all.

Where can I buy it?

Its MRO monero. Name have been changed.