60

In Ethereum, gas is a measure of computational effort. To each operation, a fixed amount of gas is assigned (e.g. adding two numbers costs 3 gas, calculating a hash costs 30 gas, sending a transaction costs 21000 gas [1]). Since computation is expensive (mind that it has to be done by every full node in the network), excessive consumption of gas needs to be ...


9

You could check by starting a geth console and using the personal.unlockAccount function: $ geth console > personal.unlockAccount("address", "password")


9

99% of altcoins claim an "innovation" that is broken or unproven. I would say that the first thing to do is look at unique codebases that aren't based on Bitcoin, which basically means (besides Bitcoin) you should look at Ethereum, Ripple, NXT, Monero, BitShares. Then if you're bored, PeerCoin / NuBits and Lisk. Once you are done with those you can look at ...


8

The current gas limit can be checked on the network stats page. It's currently 3,141,592 (pi million). The gas limit per block is not fixed, though. The number of contract calls and standard transactions is limited by the gas limit, which is 1.2x of the exponential moving average. So there's only so much gas that can be expended per block, even though it ...


8

It is much easier to formally verify the behavior space of Bitcoin script vs. Solidity. For example, the DAO project suffered from reentrancy vulnerabilities, given that one could not predict the behavior of anonymous smart contracts when they were called/sent funds to (fallback function, now deprecated). There are formal verification efforts for ...


7

Note that this question has been automatically mapped to reddit and answered there. If you declare your state variables as public, a function to read their values will be automatically created by the compiler ("accessor function"). If you use the rich interface provided by web3.js, you can create a javascript contract object and just call message() on that ...


7

A very large majority of these altcoins are essentially scams. There is a cottage industry that takes a coin, changes something minor (name, logo), and releases it with great fanfare, enticing people to buy it, allowing the forker to unload their typically worthless coins. As Нонн Болдырев said, there is a small list of worthwhile coins. I'd leave Ripple ...


7

Rootstock's smart contract features are identical to Ethereum's, both use the EVM. Contracts on Ethereum are deployable on Rootstock, and vice versa. They start to differ when you look at the networks. Ethereum has a main network where all the contracts run in a decentralized manner. Rootstock is a sidechain of Bitcoin, but it is not a two way peg, instead ...


6

A smart contract can only initiate a transaction when it receives a transaction from either another contract or a user. Thus, all transactions must originate from some user transaction, and it is this transaction that must pay for fees. The amount of fees can be limited by setting the gas limit on that transaction to prevent a malicious contract from ...


6

Start with the public key bytes (a bytestring of length 64) Of that public key, take the Keccak-256 hash used ubiquitously by Ethereum (make sure you get that right, as the ultimately standardized SHA3-256 hash differs). You should now have a bytestring of length 32. Drop the first 12 bytes. You should now have a bytestring of length 20, the Ethereum address ...


6

Bitcoin and Ethereum have different and unique blockchains. They have no relationship (other than the fact that Ethereum and all other cryptcurrencies based their design on the Bitcoin blockchain).


6

Yes, Bitcoin could also be subjected to a hardfork. In fact, there are members of the Bitcoin community that feel so strongly that the blocksize should be increased that they are proposing to do just that: They are working on a version of Bitcoin that is incompatible in regard to the current consensus rules of Bitcoin forcing a permanent split of the ...


6

The vast majority of the time, none of the 2^32 possible nonces in a particular block header template will result in the header having a hash that meets the proof-of-work target. In fact, the probability that this doesn't happen equals exactly 1 over the network difficulty. Right now, that is 1/6,379,265,451,411. When no nonce succeeds, one must change ...


5

The shorter the blocktime the more time is lost by the relaying of blocks in relation to the average blocktime. A very short block interval therefore makes SPV mining (i.e. mining empty blocks without transactions) more attractive, and increases the advantage of large pools, because they can start mining on top of their own block the quickest. Additionally, ...


5

You can separate concerns - have a contract that the users interface with and that has a reference (an address) of another contract that contains the actual logic. Then, you can control the interface contract and update it with the address of the logic contract on updates.


5

So the whole point of a name reg contract is not to send transactions, rather its sole purpose is to build up a database which other nodes can then query. Ethereum smart contracts have immutable storage. This means that you can prove your primacy to a specific name, and other people can then reference that as part of a database. What it comes down to is ...


5

They don't need to support those. As mentioned by Roman you could build the entire LN in one contract. You can even implement the LN Relative OP_CHECKLOCKTIMEVERIFY requirement in a much better way. In fact you can add more functionality than is possible with the Bitcoin LN, you could allow people to add more Ether to their side of the channel with offchain ...


5

An uncle is a block that in bitcoin would be considered an stale because its not on the longest chain (it's an alternative block at the same height as your parent). Ethereum incentivizes miners to include a list of uncles when they mine a block. This has two main effects: 1) It decreases centralization incentive by still rewarding miners that produce stale ...


5

I'll answer the middle question from the White Paper. Bitcoin can allow simple scripting and a weak version of smart contracts. The scripting that you can do has these limitations (quoting from the white paper, where UTXO means "unspent transaction outputs") Lack of Turing-completeness - that is to say, while there is a large subset of computation that ...


5

So what is the DAO's connection with Ethereum, and what is its purpose? The DAO was a decentralized autonomous organization designed to invest in DAPPs built on Ethereum Why is the operation of the DAO so crucical to warrant a fork? Whether a hard fork is warranted is being hotly debated. Ultimately miners will have to make that decision. "Too big to ...


5

It's definitely a common problem found in a lot of those platforms that make it easy to create your own colored coin/token. Asking users to acquire the native token, such as Bitcoin with Counterparty and NXT with the Nxt blockchain, is usually not a good way to start off your relationship with that customer. Some people may be fine with it, but it greatly ...


5

Most simple and foreseen reason: Bitcoin's blocktime is set at 10 minutes, while Ethereum has a block every 10-20 seconds, making it much faster. See Ghost protocol, https://www.cryptocompare.com/coins/guides/what-is-the-ghost-protocol-for-ethereum/ So no, bitcoin will probably never be able to match Ethereum's speed. ( In it's current state) (Unless ...


5

It is completely different. Ethereum offers a standardized way to create new tokens on its blockchain called the ERC-20 protocol. ERC-20 is not a piece of code, software, or technology. Rather, it is guidelines that facilitate the integration of various currencies. Tron is an ethereum based token that means it is powered by Ethereum blockchain. It will use ...


5

The Proof of Work algorithms is a probabilistic solution to the Byzantine General's problem in the case where traitorous generals represent strictly less than 50% of the generals. To simplify, the main thing a solution to this problem has to guarantee is that all honest generals (honest miners) agree on the same thing. Let's assume there are 10 miners in ...


4

I have composed one of the more comprehensive comparison charts of the various Crypto 2.0 platforms over at http://tiny.cc/Crypto (or a more direct link). It currently has pretty comprehensive comparison between Ripple, Ethereum, Mastercoin, NXT, Counterparty and BitShares, with information on other platforms also available although in smaller quantity.


4

Refer to the documentation: delete myArray[arrayIndex];


4

Is Ethereum essentially Bitcoin with a Turing-complete scripting language and, if I understand correctly, where the script to be executed (not its hash) is placed in the Ethereum blockchain? That's a bit of a simplification, (Ethereum has other improvements like GHOST) but for our purposes (discussing how a Turing complete scripting language could be ...


4

Jaxx uses a different derivation path than Coinomi when handling ETH. Coinomi opted for the path as described in the ETH specification. Ledger has the same scheme as Coinomi. Jaxx: M/44H/60H/0H/0 Coinomi: M/44H/60H/0H You will have to do the following: Delete any existing ETH wallets you have added by long pressing them (2 sec) in the Overview tab and ...


4

What Vitalik is talking about is the Slasher algorithm that he designed which punishes the block signer if he attempts to create a fork in the blockchain. However the way that slasher works is that there will be basically a timeout; if a fork is detected during that timeout, the signer that created the fork loses his money. But after the timeout, he does not....


4

promising 13k a day It is almost certainly a scam. Stay well away from this. I need to play it safe ... I simply cant afford Don't invest in volatile high-risk products such as crypto-currencies.


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