Ethereum is a world computer  and might change how we interact, just like the internet did, 20 years ago. Like Bitcoin, it is based on a block chain, but Ethereum is more than just a currency. It is a platform for building decentralized apps (dapps), which can be used for any activity that has an economic or governance aspect, such as:
Edited to add: As predicted, with the launch of the Ethereum Name Service (ENS), users and wallets have gradually begun switching over to using strings like "mywallet.eth" instead of the raw hex addresses. Because that name was not known at the time this answer was written, it refers to the same concept as a "namereg".
I can elaborate on this a little bit, ...
From George Hallam:
12 confirmations; however, exchanges and entities handling very large amounts of Ether frequently are still encouraged to run two different Ethereum implementations and only accept transactions that have been confirmed by both for maximum security (e.g. Go & C++).
For reference, 12 confirmations is approximately 3 minutes.
Every computation on the Ethereum network cost gas, so do value transfers like on the bitcoin blockchain.
Every computational step, or OPCODE requires a specific amount of gas (which is hardcoded). You pay for gas using ether. To determine the fee you pay you calculate:
required gas * gas price = fee
For example a simple value transfer cost 21000 gas, the ...
It depends on how technical your audience is, and you need to leave out a lot of subtleties, but I've been able to explain it to non-techie family and friends like so:
A Distributed System (the blockchain)
With most websites, information is stored on a server, which is basically just a computer with a database in it that has all of the site's information. ...
The main validation constraints in a Bitcoin UTXO system are:
every referenced input must be valid and not yet spent
the transaction must have a signature matching the owner of the input for every input
the total value of the inputs must equal or exceed the total value of the outputs
By contrast functionality in an Ethereum account-based system are:
Just like teaching someone about a computer for the first time, there's no need to dive into the nitty gritty details. You just have to tell them what the system does! Here's one way I might describe blockchains and Ethereum in a few short, simple sentences:
Blockchains are a way for many different people or computers to agree on something even though ...
The short answer is that Ethereum is an application platform. Blockchain technology is useful for far more than keeping track of a currency's balances, and Ethereum lets developers build applications without having to build their own blockchain. These applications can interact with each other on the blockchain, so a library of useful functionality will ...
The geth client waits 5 blocks for confirmation of fresh minted blocks (around 1 minute).
I0201 19:07:07.354260 9098 worker.go:349] 🔨 Mined block (#1483 / a2648b58). Wait 5 blocks for confirmation
To make sure a block is no uncle or a transaction included in a block does not hang up in an ommer, I would suggest waiting 7 confirmations (around 2 ...
Yes and no.
No - a Bitcoin address cannot be directly used in Ethereum, and vice versa.
Yes - underneath, a bitcoin private key is essentially a random 256-bit number (in a certain range, see bitcoin wiki). And the private key's corresponding public key is essentially the x and y coordinates of a point on an elliptic curve. Bitcoin and Ethereum both use ...
Yes, both cryptocoins use the same elliptic curve SECP256K1.
Perhaps a better alternative is to use a BIP32 wallet. You have a master key that is not directly used for transactions, but it is used to derive child keys than can be used.
You can derive separate keys for bitcoin and ethereum. You will always be able to use the master key to sign transactions ...
If you want to download the blockchain data from an external source that is up to you, but that does come with risks of the data being corrupted or sabotaged in a way to compromise your machine or Ethereum wallets. So the "security issue" is that you are trusting an un-trusted, non-Ethereum network source when you download the file. As long as you ...
Ethereum theoretically approaches finality in less time than Bitcoin, due to the GHOST protocol. This means that, with a 15 second block time, roughly 40 blocks are needed to match the 60 minutes that 6 Bitcoin blocks takes.
Therefore, assuming no major consensus bugs, 40 confirmations should be more secure than 6 confirmations in bitcoin. In practice, ...
Currently, Ethereum uses elliptic curve cryptography (ECDSA), the same as Bitcoin. So whatever "unsafe" concerns there are with how Bitcoin transactions are signed, would be the same with Ethereum currently.
In Bitcoin and Ethereum, sending from an address will reveal the public key easily. Quantum computers compromise ECDSA and would make it easy to ...
From this slide presentation from Ethereum's Developer Conference 2015, Ethereum is an application platform for "Not just money! Asset issuance, crowdfunding, domain registration, title registration, gambling, prediction markets, internet of things, voting, hundreds of applications!"
The rest of the video presentation offers further introduction to ...
In short, in Ethereum the fees are paid in gas and calculated based on contract code execution complexity, in bitcoin the're based solely on transaction size.
See the these Ethereum gas fees tables ( table1, table2 ) for the complete gas costs for executing contract code.
The fee for a value transfer is 21000 gas, you need to check the current gas price on ...
1. Explanation for an absolute non-techy
Lets first take a step backwards: How would you explain a conventional computer to a non-technical friend? A device that performs computations perhaps. Most non-technical friends probably get that.
Ethereum is the same, only that instead of being a single computation device that you have physical access to, the ...
Ethereum is a platform like the Internet.
Most of the Internet is made of computers that are centralized: meaning they belong to one company or government.
The problem with this is when something happens to the one company, whether it is Facebook, Google, Apple, etc. then you either cannot talk to friends, do searches, and so on until the company is able ...
From Vitalik Buterin says in Ethereum blog at 2015/09/14 about the topic of discussing "On Slow and Fast Block Times"
only a small number of extra confirmations (to be precise, around two to five) on the faster chain is required to bridge the gap; hence, the 17-second blockchain will ...
The recipient of an Ethereum transaction can only ever be a single entity, as specified by the Yellow Paper (http://gavwood.com/paper.pdf) page 4, section 4.2, to field.
However as you mentioned, a contract can itself create multiple transactions as a result of a single invocation.
No; Ethereum and Bitcoin's consensus algorithm is very different from Raft and Paxos. Ways in which they differ:
In both Raft and Paxos, the systems elect a leader. There is no leader in Ethereum and Bitcoin.
In both Raft and Paxos, all members of the cluster are trusted. In Ethereum and Bitcoin, one needs trust in only 51% of the holders of hash power.
The fundamental difference between Ethereum and Bitcoin is that while Bitcoin uses a UTXO model, Ethereum uses a state-transition model.
In Bitcoin, in order for a transaction to be valid, it must point to a set of Unspent Transaction Outputs, which then become the inputs for that transaction. The output value of the transaction must equal the sum of the ...
The primary critique of Ethereum made by leading members of the Bitcoin community is that the Ethereum network created a new token, ether (ETH), instead of finding a way to utilise existing bitcoins (BTC) as the unit in which operations are priced. Obviously this is not a criticism which can be levelled against the Bitcoin network itself.
Since this ...
Let me try to explain.
Bitcoin Block Size Limit
The Bitcoin side is pretty simple to understand. The bitcoin blockchain has a hardcoded block size limit of 1 MiB. With an average transaction size of around 600 B and a target block time of 10 minutes, you get
1024 * 1024 / 600 B = 1747.7 transactions per block,
which translates down to
1747.7 / 600 s = 2....
It's called the Transaction Pool, or TxPool in the code.
From go-ethereum - tx_pool.go, lines 35 to 62:
// Transaction Pool Errors
maxQueued = 64 // max limit of queued txs per address
// TxPool contains all currently known transactions. Transactions
// enter the pool when they are received from the network or ...
I've seen exchanges use 375 confirmations. But as the difficulty increased and the network got more decentralized, it's safe to go way below this.
Of course it depends on how critical the transaction is. As a rule of thumb, wait at least 5 confirmations for amounts higher than $500.
Then, add 5 confirmations for each $1000 the transaction is worth.
Ethereum addresses do, now, have a checksum.
See EIP55 for the specification and updates about implementation.
It is optional for use, but if you see a mixed-case address it should be validated according to the following rule:
Convert the address to hex, but if the ith digit is a letter (ie. it's one of abcdef) print it in uppercase if the 4*ith bit ...