105

The fundamental flaw of Proof of Work (PoW) is that the costs of attacking the system are equal to what is spent to run the system. High security thus can only be achieved at high operating costs. The idea is that the honest participants just outspend the dishonest. This is already today highly inefficient, but it does work for Bitcoin. As soon as the ...


60

There are two key motivations for the move to Proof of Stake: Ethereum developers and researchers believe that consensus algorithms based on Proof of Stake (PoS) can provide a higher degree of security for a given amount of resource expenditure, compared with Proof of Work (PoW) consensus algorithms. Ethereum developers and researchers believe that a new ...


41

It's not certain yet, but: Do NOT rely on very fine-grained calculations of current gas costs. Assume that gas costs of contract calling may go up or down by up to an order of magnitude in a future hard fork. If creating contracts in assembly (ie. not serpent, solidity or LLL), do NOT use dynamic JUMP/JUMPI operations (ie. every JUMP/JUMPI should be ...


31

That is very complicated topic. Considered Proof-of-Work waste energy to maintain security of a public censorship resistant consensus ledger. Though there is a long standing debate about this point. You can see for yourself that Bitcoin consumes more than $1 mln of value per day. Energy consumption on hash calculations is estimated to be around Iceland's ...


14

Yes, you can guarantee long run time accuracy. Miners can't cheat that much to change the timestamp over days. Blocktime is adjusted to be constant within certain error margins, and timestamps is guaranteed to be rejected if they are excessive. Serenity and PoS 'proven' until core team decides otherwise. It is very very unlikely to happen, what reason could ...


14

According to Vitalik Buterin on r/ethereum, the difficulty bomb was slowed down with homestead a bit. As it turns out, with the change in the difficulty adjustment algorithm brought about in the last hardfork, the ice age will come very slowly indeed. Originally, the maximum amount by which the difficulty could adjust was 1/2048x, and so given a natural ...


14

In his DEVCON1 Keynote, Vitalik Buterin addressed the roadmap of Ethereum beyond the Frontier release: homestead, expected when the ethereum network, miners and other critical components work without serious hiccups for about 4 weeks. metropolis, with focus on the mist browser. serenity, Ethereum 2.0, with 4 primary research directions: casper, the proof-...


13

You don't need to have lots of full client nodes. Nowadays you can download the light-client version, which implementing Merkle Tree structures, lets nodes to don't be obligated to store ALL of the data on it's hard drive. Some use cases for a fully light client, and how the light client meets those use cases, include: A light client wants to know the ...


11

Highlighting: Every time a user signs a transaction, that transaction is factored into their own individual moving average. Any time a user’s moving average exceeds the current network limit their transaction is delayed until their average falls below the limit. Rate limiting based upon balances implies that there exist unique accounts with publicly ...


9

The changes to the code were made in August in this commit, with the meaty parts of the maths being found in core/chain_util.go. The constant increase in difficulty is due to an additional exponentiation step in the algorithm. A quick back-of-the-envelope calculation can be found here, and would suggest that after 22 months (from August 2015) the average ...


9

The biggest risk is, as in Proof-Of-Work, centralisation. Centralisation of staking power in the 'hands of few' with the very deep pockets. To mitigate this risk, Ethereum founders decided not to engage venture capital on the early stages (and hopefully on any stages). Another measure was to hopefully create a diverse enough initial distribution of Ether in ...


8

In a naively implemented proof of stake, suppose that there is an attacker with 1% of all coins at or shortly after the genesis block. That attacker then starts their own chain, and starts mining it. Although the attacker will find themselves selected for producing a block only 1% of the time, they can easily produce 100 times as many blocks, and simply ...


7

The "processing power" of the EVM is unrelated to mining hashrate. Power is not an accurate phrase for the EVM, because what limits computation on the EVM is cost: gas used multiplied by gas price. The Ethereum protocol does not provide limits on what the gas price and block gas limit can trend to. Heavy computations are possible on the EVM, but they ...


7

Everybody knows what addresses were inputs to the ring. So when you withdraw, everybody knows your output address is linked to one of the input addresses. But nobody knows which one. This is an improvement over the usual situation where funds can be traced from address to address. It's helpful in some situations. Say you have an address which as been linked ...


6

Credit: @Vitalik in the Ethereum Research Gitter Chatroom: As of January 11, 2016: How should the staking rewards and penalties (more precisely, the parameters for the scoring rule) for CASPER be set? How many validators should CASPER have? Given this value, how should we target it? What is a good target level of participation (as in, % of all ETH staked)? ...


6

Nope. Nothing in blockchain is fully anonymous. Just very difficult to track down. Almost to the point of not worth trying to unless you did something really bad and there's proof it came from your address. And even then. Linking address to identity is difficult in and of itself.


6

Quoted from Vitalik Buterin on Reddit: (https://www.reddit.com/r/ethereum/comments/4d5z1y/is_it_possible_for_bitcoin_to_live_on_the/) "BTC -> ethereum convertibility can be done fine; the hard part is the ethereum -> BTC conversion. There would need to be some kind of sidechain protocol that can "understand" receipts being created on the ethereum ...


5

The miner could cheat in the timestamp by a tolerance of 900 seconds. so if you check outside this intervall you are safe.


5

The property of anonymity offered by ring signature mixers is more like what you would intuitively think of as 'plausible deniability', or 'anonymity with respect to an anonymity set'. The actual definition of anonymity is given as an adversary having only negligibly greater advantage of connecting the true input-output address pair than if he were to guess ...


5

Someday the Ethereum blockchain will hit 1TB, but it won't be soon. I've been installing full mining and non-mining nodes with geth with "fast" disabled. A fresh install of the blockchain fits nicely in under 120GB today, and that is only up about 40GB from last December. That's around 40GB in nearly half a year. Even if the Ethereum blockchain triples it's ...


4

March / April 2017 Update from Vitalik Buterin about Casper Relayed by Jim Manning in Eth News Still needing to get done: (1) Completing the code of the CASPER contract (3/4 done). The 25% remaining to be implemented is: A sequence number mechanism on messages (needed to fully verify slashing conditions) Switching from checking ECDSA signatures ...


4

When it's (nearly) ready ! Ethereum is highly innovative, and developed in 'agile' mode. Even the content of the releases may be swapped or changed. So, that kind of product is released when the end is in sight... The latest roadmap seems here, making Mist(Metropolis) by early2017. And Casper PoS (Serenity) should be next.


4

Ethereum is a decentralized network so nobody has the last word on what is "official". Vitalik may propose something and everyone may ignore it. The closest thing Ethereum has to an "official" organization is the Ethereum Foundation, but AFAIK it doesn't make technical decisions, and it isn't in control of the software people run so even if it did people ...


3

I'm not an expert. But you can implement any currency in Ethereum. So nothing prevents you to do so. However, everyone (at least every miner) would have to agree at some point and make a migration process. Something which freezes bitcoin network transactions forever, and the only possible transaction is paying TO "someone" who grants the owner of the sender ...


3

Because it's completely integrated into the protocol and all interoperable. Side chains imply that there isn't really a consensus underneath that binds the two, it's sort of hacked together. Shards all operate under the exact same consensus structure.


3

The switch to the Casper Proof of Stake protocol will happen in the Serenity release, and the latest information is from March 5 2016: The protocol decisions made here are by no means final; many of them are still actively being debated within the research channels. The next few rounds of PoC releases will thus move toward creating something ...


3

This implementation here demonstrates how to do it in Ethereum using a Smart Contract and Byzantine precompiles: https://ropsten.etherscan.io/address/0x5e10d764314040b04ac7d96610b9851c8bc02815#code The corresponding discussion at reddit: https://www.reddit.com/r/ethereum/comments/75rzdn/linkable_ring_signatures_on_ropsten/


3

Casper is the proof-of-stake protocol. There are two being developed, one by Vitalik Buterin and another by Vlad Zamfir. Vitalik's is known as Casper FFG. Vlad's is known Casper CBC. They are NOT complementary AFAIK, but rather being developed in friendly competition based on differing philosophies. I suppose one of them will be selected or perhaps ideas ...


2

The current problems are...whether or not it will work really. Basically the algorithm can be boiled down to acting like a prediction market. This should work in theory but whether it works practically in reality is another matter. But we'll know more once it is on the test network. Until then, there's not a whole lot to critique as it is still being ...


2

The biggest risk to proof of stake is "nothing at stake". The "slasher" solution to this isn't tested and may not work. "proof of burn" is similar, possibly safer. But the bigger risk is not switching. Ethereum contracts may be too expensive if a switch isn't made.


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