First, there is the scaling problem. You might think that this only affects Bitcoin, but in fact it's the same for any other cryptocurrency - they can't process more than 20-30 transactions per second at best, while visa is processing around 3000 transactions per second. There will be lots of improvments with cryptocurrencies that will increase their capacity, but demand will also be growing, because right now only around 40% of humanity has access to banks.

The other factor is how attractive they look, in comparison with traditional currencies. Most users won't care about decentralization and financial freedom, they need fast, simple, cheap payments, and if cryptocurrencies won't be able to provide this, than they will be mostly used by people who need their special features.

I'm sure that cryptocurrencies have a bright future as assets, but their utility as currency remains uncertain. I have a very high hopes for the Lightning Network though.

There's a lot of good responses here already, but I want to add that password strength is usually measured in bits of enthropy, for easier comparison with recommended values of security level. For a long time 80 bits of security were considered the minimum requirement, but now this number was increased to 112 bits.

So, how many bits there are in your example? Well, the formula is easy -



Your L is 8, while your N is 10,000, so H = 106.3

This means that it's unlikely to get brute forced now, but it might become crackable in 10-20 years with your home pc.

Bitcoin and other cryptocurrencies are only valuable because they are so decentralized, and no one can get robbed of their coins forcefully. There were some payment systems in the past, like e-gold and Liberty reserve, and they have failed because they were centralized and it was very easy for the government to take them down. Decentralization comes with the price of increased security costs (mining), and lower scalability, as well as requirement for consensus between all users, but this is the only way to ensure our financial freedom from governments and banks.

It will depend on the price around October, if we assume that there will be economic split due to SegWit2x hard fork. This situation might be different from BCH fork, because SegWit2x fork has no replay protection, meaning that it will be harder to use two coins separately. SegWit2x also has much more support, especially from miners and some companies, so this split might cause a drop to $2500.
On the other hand, Bitcoin can behave very unpredictably, for example it was very stable during BCH fork, while many believe that it will drop. So, it's also possible that we might never see prices below $3000 or $3200.

I was making a thread here about this issue a few weeks ago: https://bitcointalk.org/index.php?topic=2041411

Sadly, most people didn't understood the issue or refused to address it, but there were some helpful posts. In general, you should avoid small betting sites and lowest tier matches if you don't want to fall victim to match fixing. The more professional the players, the lower the risk that they will participate in this type of fraud.

I think mining centralization can be a serious nuisance for the Bitcoin network, although not an existential threat. Launching 51% attack, which is the worst case scenario, is very unlikely, because of giant costs of it, and it can only stop the network and make some double spending. But there are other attacks that can be achieved by having significant amounts of hashing power. Right now majority of miners come from China, so we can imagine scenario when Chinese government orders miners to not include transactions of some foreign companies, creating artificial delays for victims. Miners also hold some political power over Bitcoin, because they can block proposed changes. In the long run, miners follow the market, but in short term miners also have some influence over the market.

That's a good point, governments can outlaw Bitcoin, making it very unattractive and risky for investors, but I don't think that they will do this, because right now Bitcoin has public ledger that can be utilized for tracing transactions, so governments can monitor big money flows in Bitcoin, but if it will be pushed to the darknet, it will evolve to become much more private and will be widely used in shadow economy. So, I think the most likely scenario is that governments will find ways to regulate Bitcoin without trying to affect the network - i.e. having companies to register their Bitcoin addresses, pay taxes in Bitcoin to government wallets, etc.

That's wrong, if some altcoin was really better than Bitcoin, it would take Bitcoin's place rather quickly. In real life better technologies replace old ones in a span of few years, but in crypto world, with 24/7 trading and quick implementation of new networks, this process can happen in just few months. The fact that Bitcoin dominates the crypto market only proves that it has the best technology, and all altcoins are just experiments and don't pose any significant threat to Bitcoin. Very often their innovative features negatively affect the main thing that makes cryptocurrency valuable - decentralization.

If you are accepting transactions, especially in high amounts, then running a node is a matter of security, since lightweight clients like Electrum have to trust full nodes they connect to to some degree. Running a full node also makes Bitcoin more decentralized and secure, which contributes to it's price, and the higher the price of Bitcoin, the more security we need, to discourage attackers from launching their attacks. Anyone who has spare disk space and bandwidth should run a full node on their computer, you don't need to run it 24/7 to contribute to Bitcoin, just leave Core wallet open in the background when you are using computer.

You could relatively easy implement it on wallet level (but this would be kinda useless), by simply not allowing user to choose higher/lower fees in GUI and updating prices from some remote server, but implementing this on node level would be very problematic, because nodes should always agree on rules, so this new fee parameter would require all nodes to be in sync with some single server, which would be a huge security weakness.

There's a common misconception that this is a debate only about scaling, while actually the major point of disagreement is security. Core is not arguing that bigger blocks, and especially bigger blocks with SegWit would quickly boost Bitcoin's capacity and lower fees for some time, but they believe that this will dramatically reduce number of full nodes, making Bitcoin less decentralized and secure. Small number of full nodes will make Bitcoin weak to government attempts to shut it down as well as different kinds of double-spending attacks.

There are lots of problems with GPU mining for GPU manufacturers. The demand is very unpredictable, when altcoins rise, miners will buyout all GPU stocks and leave nothing left for gamers, when alts crash, mines will sell used GPU's or even RMA them, both resulting in losses for GPU manufacturers. This volatility of GPU market is causing some gamers to switch to consoles, and there's no simple way to fix it, because specialized GPU's for mining might be unattractive, since you can resell them to gamers. The best way for GPU manufacturers would be to start producing ASICs, but it's also a very risky investment, especially considering the uncertain and unpredictable legal status of cryptocurrencies.

If you take some simple game like Dice, there' very little attack surface, even for AI. But there's one common thing for any online gambling site - random number generator. Successful attack on casino's random number generator can allow attacker to get edge for his bets, or even predict outcomes with 100% certainty if RNG got completely broken. It's possible to do it even now, but maybe new AI methods can do it even more efficiently, so casino operators should be cautious of this threat.

Well, it's obvious that if you are not risking anything valuable, you won't feel any excitement. Gambling games themselves are very simple and not very interactive, so very few people would play them if there's no risks involved. Faucets are good for testing games, checking seeds, doing a few bets if you are bored, but people who are spending hours on them are just wasting their time.

I think this will be much more complicated, because devs of SegWit2x call their coin Bitcoin, unlike Bcash who at least honestly distinguished itself from Bitcoin.

People who run online wallets will have power to decide for their users which chain is Bitcoin, and it can be huge. For example, Coinbase is a part of NYA, and in worst case scenario they will push 2x as Bitcoin and refuse to support Core chain, so suddenly all their customers will only have 2x coins.

There was a huge volatility around Jul 20th when the situation with SegWit was uncertain, and this might repeat in November.

Quantum computers are being developed gradually, it will take some time for them to be able to crack ECDSA cryptography. By that time we might already have a hardfork that will change current public-private key algorithm of Bitcoin to something quantum-resistant. Also, you should know that Satoshi foresaw the risk of vulnerability in ECDSA, so public keys are also protected in Bitcoin - they are encrypted with SHA256, and only get exposed after an output is spent. So, even if someone will secretly have a powerful quantum computer, they won't be able to destroy Bitcoin by hacking everyone's coins.

Bitcoin is the king of crypto because it has the best team of developers who know how to preserve decentralization and security that makes Bitcoin valuable in the first place.

Altcoins can't flip Bitcoin because they don't offer any breakthrough innovation, they all have the same problems as Bitcoin, and new features that they offer are usually very experimental, risky, or even just useless.

SegWit2x developers and miners are not backing down from their intention to hardfork in November, while the upcoming update for Bitcoin Core client will be automatically disconnecting SegWit2x nodes.
The possibility of chain split looks very high, which raises a few questions.

How exchanges will be naming Bitcoin chains after split - will they name one as a Bitcoin, or rename both to something like Bitcoin Core and Bitcoin2x?

What will be the prices for those coins? How their value will change after a few months?

Will combined value of both coins increase or decrease?

It would be a huge mess, if you don't have 100% of miners and nodes agreeing to blacklist some address, it would cause a chain split. And this will happen with every new address added to blacklist. And if someone hasn't updated their list fast enough, they will also get kicked into alternative chain. Miners will have some of their blocks orphaned for the same reason. Users on minority chains will be extremely vulnerable to double-spending attacks. It's simply not worth it, so no one will ever try this thing.

Each output adds 180 bytes of weight to transaction, so if you'll take 1sat/byte as fee (which might get rejected after hanging for some very long time), you'll get a minimum amount that can be moved - 181 satoshi. If you'll use higher fee, you'll have to multiply fee/byte and 180 bytes to get a new minimum amount.
To get the best possible returns out of your dust, you need to wait for a moment when mempool is empty, you can track it here: https://blockchain.info/charts/mempool-size
Recently there was such opportunity during BCH hard fork, and you could have moved your dust just for 1 satoshi per byte. In the future there might be a new opportunity when SegWit will get activated, or before November hard fork.


If you want to get good rate (i.e. extracting 25 mBTC out of 30), you'll have to wait much longer, a few weeks maybe.