Use a Raspi and co, any platform. If it has 1GB it's enough.

Blackcoin is staked, not really mined. You don't try for hashes so Blackcoin needs very little CPU (not much more than creating an SSL connection, decrypting an email or hashing a file). So you can mine a CPU-miner coin on the same box that runs Blackcoin staking. However what Blackcoin, as any other coin, might need is some RAM. 1GB is maybe a little thin to run many coins on the same box.

The only way to limit voting right now is binding the votes to some kind of a value, be it hashpower or investment in the blockchain. That's the whole reason why all of this exists. You want the decentralized system to be anonymous (or pseudonymous at leas) at the same time too, because the most free form of voting and participating is the anonymous one, and you will want to make voter fraud as expensive as possible. The system also has to be trustless, that means you are not required to trust a voter to play fair.

That's just how it is.

Maybe they should but they are not required to in order to run a PoW farm.

But Bitcoin is open source. Running a crypto currency as a closed source software is just plain retarded and everything else but decentralized.


There are bots in literally every game and not only in online-poker where you can win real money.

This wouldn't really be a problem as the more coins the more diversity. Actually I wouldn't mind, if we have one coin for every niche. The only problem here is usability but that also can be solved, when the coins are just compatible with something like atomic swaps, where you can exchange one coin with another using smart contracts, no matter what blockchain you actually use to transport the contract on.
https://en.bitcoin.it/wiki/Contract#Example_5:_Trading_across_chains
https://en.bitcoin.it/wiki/Atomic_cross-chain_trading

And as long as some coin is at least worth 1 satoshi, you can use that coin for exchanging assets.


This is the actual problem, how do you just prevent bots. And the bot doesn't even need to do the whole game, it's enough when you have like an aimbot that helps you leveling up x game characters to have a benefit in "mining" (or how ever it is called then) the blocks.

On the other hand what I could imagine would be an in-game currency that uses a blockchain or in general a ledger for in-game assets. That'd be a niche for an actual coin. The coin then can be centralized or decentralized as desired.

Please, do yourself a favor and store the BTC somewhere else not online.

At best, send them to a paperwallet/brainwallet address.
https://walletgenerator.net/
https://brainwalletx.github.io/

No one should use online wallets no matter what, unless they need them for instant trading. In general: If someone else but you has access to your privkey, consider your BTC being or getting stolen.

So you are either extremely foolish with your coins or you don't tell the truth.

The reason 51% are not tried right now is that it is just impossible for a single person to get the ~17 Exahash/s you'd need. That's said for a single person, but not for a pool and also not for a manufactor of a miner who everyone uses. And if you manage to attack the miner's firmware, you'd lose no money at all, same if a pool reaches 51% and you'd attack it.


See above. Also, as said, in PoW miners generally don't care in the coin's health after they cashed out their profit, because they don't need to care about that. They will just move on to the next profitable SHA256 coin and continue. That's because miners in PoW don't have to hold any share in the Blockchain's value. That is different with PoS or with a PoW where you'd have to put a bail on a coin for each block you submit. If miners would care about a coin's health, they wouldn't all just cluster up on the same pools.

Well, Bitcoin is the most accepted, everyone that accepts crypto payments also accepts bitcoin. Some also accept Ethereum, Litecoin or even Doge but everyone accepts Bitcoin.

That is true when the foul spending is significantely smaller than the 12.5 BTC (or later on even less). That is a far smaller value you'd destroy than when you have to buy 51% of all coins in existence to attack PoS.


Well as for SHA256 there are plenty of coins to mine on, take alone all the BTC forks.

And both don't apply to governments and other that just want to harm cryptos in general. And please mind the fact that here it was also said that there is an issue with single manufactors having too much power over the mining industry with their firmware and that there are backdoors has been shown with "antbleed".

As for a discussion of security matters, I always found the motivation of a possible attacker not a valid argument. It's like when someone asks why someone should use a secure password for Facebook or their email since they have nothing to hide. You can never expect a reasonable motivation of an attacker.

The one of the biggest strenghts of Blockchains is the decentralisation of the ledger and a pure peer 2 peer network to maintain asset operations. This however doesn't exist if the Blockchain is not well decentralized at all.

No. Your node validates transactions but you need a base to validate them on, and that base is the history of the longest chain. That's why in a double-spend attack the attacker prepeares a fake history, then she does her 1st spend and issues a fork of the history that doesn't include her own transaction. Your full node will see the fork and trust the longest chain, which comes in this case from the attacker who then can spend her coins again.


"One-CPU-one vote" in his paper, Satoshi did not expect miningpools to take over. Originally it was intended that every user of full nodes particiates in maintaining the Blockchain by giving some of her CPU-power to the network and earning a reward for it. Today we have a mining industry that has no interest in the coin what so ever as long as they make profit from it. They don't even have to use the coin at all for anything else but to sell the reward for their profit.

Other protocols like PoS are more close to Satoshi's orignial intend, where everyone who has a wallet open stakes a part of their coins to keep the Blockchain running and by attacking the Blockchain they risk losing their own investment they have in the coin.

Yes, there are risks but the risks are at 0% when you have 51% of the network weight. Anything below 51% can make your foul play fail, at 25% you have a 1% chance of success over 10 confirmations. But as soon as you pass 50% you have 100% of success for your foul play, no matter how many confirmations from the network (all full nodes) you get. The propability graph is expotential with reaching 100% at >50%



(see https://bitcoil.co.il/Doublespend.pdf).

BIP148 and NO2X don't fix the majority attack at all.

The "profit and greed" issue has a slightly different aspect. Attacking a PoW coin with 51% would make you lose no money other than what you have spend on energy cost. The mining rig you used for that attack (if it's yours at all) could be sold after the work is done and compensate a part of the energy cost. With PoW you don't need to have any value in the Blockchain, you can point your miners at any Blockchain you desire and the coins you earn will be spend for your profits. In other protocols you risk your own investment in the Blockchain when you attempt to attack it, or as Vitali put it: "Attacking proof of stake is like buying the biggest mining rig and set it on fire".

51% always works, no matter how many confirmations you wait, as long as you manage to provide 51% over that time. With 51% of the hashrate you always write the longest chain that, in a dispute, other nodes will always trust. That's why 51% has a 100% success rate.

In the current Bitcoin network it's nearly impossible for a single miner to get 51% since the global hashrate is at 34 Eh/s, that is ~3,000,000 of the best current antminers. However for a pool it's possible to reach that, the biggest 3 pools already have more than 51% of the hashrate and pools getting to 51% have happened in the past.

With the old mining-protocol getwork, pools could just use their workers to manipulate the chain for them at literally zero cost since getwork only gives to the miners the blockheader to work on and hides the content of the transactions from the worker. A malicious pool would be able to manipulate the transactions and let their miners provide the proof. That's why getblocktemplate was invented where miners get the whole block and thus a pool could not manipulate them. However getblocktemplate is not enforced by the network as the network only sees the pool issuing new blocks and checks the blockheader for correctness, it has no information about the miners behind that pool. So it's up to the miner's firmware to only accept getblocktemplate protocol.

Another story however is the power of miner manufactors like Bitmain who are estimated to provide 70% of the global hashrate. A backdoor/vulnerability in the miner's code could enable the manufactor or an attacker to manipulate blocks for them - again at basically zero costs. Bitmain had an open backdoor in their firmware that allowed Bitmain or an attacker to shut down miners from remote (http://www.antbleed.com/). This didn't enable a 51% attack directly but could have harmed the network like a massive dDoS on the hashrate. The backdoor is supposed to be closed but the general problem of a proprietary firmware providing the majority of the hashrate remains.

How does that fix the problem I described?


That's why I posted the link, it's explained there in detail. The code backdoor was fixed already but the problem remains, when a single manufactor basically has control over a large part of the hashrate. In "antbleed" there was a code in the firmware, that allowed Bitmain to shutdown miners, collected metadata about miner usage, expose miner users to government and also could be exploited by third parties due to vulnerability in the backdoor code.

With Bitmain's maschines providing most of the global hashrate, this is still an issue since there is still the possibility for more intended or unintended vulnerabilities in the firmwarecode.

When you have more than 50% of the hashrate, you make more than 50% of the blocks. That means, your chain of blocks will always been the longest. Since the network generally trusts the longest chain, the blocks of all other miners can't compete against you. Therefore you can manipulate the chain long enough to fabricate your own transaction history and trick nodes into thinking that an amount you already spend is still unspend and thus you can run a double-spend attack (the very thing the blockchain is supposed to prevent).

The network is still decentralized but in a dysfunctional way, means your miner will control the whole blockchain no matter what everyone else on the network claims.

Quantum computers can run multiple guesses parallel and that enables them to guess a private key to an address with no effort at all. If quantum computers exist, all hashing and encryption methods that are industry standard today become useless. However when that happens, we need quantum resistant algorithms anyhow everywhere on the internet and Bitcoin can implement one of these algorithms too. Quantum computers can steal your coins by just guessing your private key if they know your public address, since every public address is generated from a private key. It's an one-way function that means, calculating a public key from a private is simple but the other way around is extremely difficult, however quantum computers can do it by just trying in literally no-time.

No, public keys are generated from the private key and each private key creates exactly one public key whose hash is the 160-bit public address. So with owning the private key (backup, paperwallet ect) you can always and at any time (re)create your public address. So two different privkeys can not prove ownership to the other's public address. The wallet does that with picking the correct privkey from it's internal database (which is a mere key->value pair).

And actually there are no "coins" and the "wallet" is, as said, just a piece of software that helps you operating your keys. All that exists is an entry on the blockchain that says "address X sends to addres Y w.z coins" and if address x can prove, that they have gotten at least w.z coins before and that this amount was unspend, the network will know that address Y now can sign a transaction of at least w.z coins to a third address.

The miner's "arms race" has become the biggest issue for the Blockchain. It doesn't simply work as intended and changes are neccessary to fix this problem.

Yes, the problems are not immanent in the protocol or the design of the Blockchain but rather in the people who use it/respectively try to profit from it. That has allowed manufactors like Bitmain to literally take full control over Bitcoin. And while getblocktemplate was implemented against malintent pool owners or -attackers, the power of miner-manufactors over the blockchain remains unsolved.

Bitmain's own proprietary firmware controls 70% of the global hashrate in Bitcoin.

http://www.antbleed.com/

The mining industry doesn't give a damn for the coin or it's health, all they are interested in is their profit. And PoW enables them to operate and control the Blockchain without requiring them to hold any value in it. If things like "antbleed" continue to exist, PoW is to be considered broken.

Limitation of hashrate, as difficult as it might be to implement, would render all ASICs useless and require people to return to their GPUs and CPUs and thus diverse the hashrate again over a lage variety of firmwares and hardware implementations. If one'd require miners to put a bail on the blocks they create using their own coins they hold, they would be forced to have a value in the blockchain, hold a certain amount of coins for their daily mining business and also risk their bail when they attempt to manipulate the blocks they issue.

Although I am aware that changes like this will probably never be implemented due to the political power miners have over the Blockchain and a change like this would damage their mining business as all ASICs would become worthless over night. That is, unless a huge portion of the community puts pressure on the Chinese mining industry and forces them to comply.


This is true for a commonity like Gold but not for a currency. A currency needs to be stable and fluid.

But how do you determine when someone's clock is running? You need to have entities verified and that verification needs to be based on something someone can not easily create out of thin air. You could use addresses to verify but each pool could for each block they issue create a new address. That's why I brought up coin ownership, because that's what PoS uses to limit the amount of blocks someone can create with something they can not create out of thin air. So if you would like to create a block also send a transaction of part of your coins to a stake and then these coins get market as "bail" for the block, this "bail" decays over time until you can use the same coins to issue a new block.

Yes, that's basically what Sybil attack means. This would have to be solved to have a hashrate-limit taking place.

Maybe you could tie the hashrate to coins you own. So let's say to issue a block you must prove ownership of a balance and that bail on these coins decays over time before you can use the same coins again to issue a new block. You can not limit nodes but you can utilize other limits everyone has like coin ownership.

Well Monero at least aimed at the CPU miners and didn't cater to GPUs. That is, until ASICs for Monero appeared and all what Monero can do against this is frequently hardforking their coin to a new algorithm to prevent ASICs from taking over.