Questions tagged [blockchain]

The Ethereum blockchain is a distributed database based on the Ethereum whitepaper specification and stores both the full transaction list and the most recent state.

Filter by
Sorted by
Tagged with
7
votes
3answers
4k views

How can you parse blockchain files stored in a local node to get blocks and transactions details?

I want to get all details of blocks and transactions without using event logs. For example, I want to get a list of of transaction data which are sent to a specific contract. How can I parse local ...
6
votes
1answer
1k views

How can you implement two way pegged Ethereum <-> Ethereum sidechain?

If you want to create an Ethereum sidechain which is two-way pegged to main (public or private) Ethereum, how can you implement sidechain? For example, How can you lock ether? How can you verify ...
6
votes
2answers
970 views

Is there an easy, human centric way of viewing local Ethereum blockchain data?

Etherchain and Etherscan provide information about the Ethereum blockchain. What tools exist that will allow me to extract similar data from my local Ethereum (.ldb) files?
1
vote
1answer
179 views

Does a DAO protect real inventors from Patent trolls? [closed]

The DAO is a Decentralized Autonomous Organization” (DAO); it can be defined as:- a fully automated business entity (FAB), or distributed autonomous corporation/company (DAC) is a decentralized ...
7
votes
3answers
1k views

What is actually removed during a contract suicide, and why doesn't this cause the blockchain to change?

I'm trying to get my head around how contract suicides work, and what actually happens during them. I understand why we use them. This post states that when the SUICIDE opcode is executed, the data ...
8
votes
2answers
3k views

Is there any SPV client for ethereum?

I am looking to move some ETH from an exchange to a wallet for which I control the keys. I don't, however, want to download the whole blockchain. Is there a good SPV client I can use?
8
votes
1answer
322 views

Implementing Fractional Reserve Bandwidth Concept in EVM on Serenity

I recently came across this piece by Bytemaster of Bitshares: "How to build a Decentralized Application without Fees". It's actually a very interesting piece that details how one might run a ...
18
votes
1answer
3k views

Difference between a pruned and unpruned blockchain

At the Berlin Blockchain Meetup, Gustav Simonsson teased the Homestead release coming soon (tm) and we were discussing blockchain bloat and the current size of the Ethereum blockchain. We discussed ...
93
votes
2answers
85k views

What is Geth's “fast” sync, and why is it faster?

One of the answers to this question suggested using Geth's --fast flag to help quickly synchronise the block data. How does the flag work, and how does using it speed up the synchronisation? Are we ...
9
votes
2answers
6k views

Corruption on data-block while synchronising

My home server's been down for a couple of days while I do some upgrades. I'd had Geth running in one of the terminal windows, but shut it down gracefully using exit before taking the server offline. ...
5
votes
2answers
786 views

Is it recommended to run Ethereum supernodes?

In the early days of bitcoin there was a demand for system administrators who were able to run supernodes to support the network with stable nodes and high bandwidth. Litecoin is still recommending ...
1
vote
0answers
83 views

Why is my node taking so long to sync? [duplicate]

I downloaded the ethereum wallet, and its taken a few days yet its still syncing. Im on block ~701,000 thus far. Is something wrong? Is it supposed to take this long?
7
votes
1answer
564 views

How could Banks or Accounting Firms use Smart Contracts?

I keep reading how banks and accounting firms are researching into blockchain tech specifically smart contracts, but I don't quite understand how a company will apply them to current work. One way I ...
2
votes
1answer
551 views

How do contracts interact, and how is the network secured? [closed]

I don't understand what it means when people saying things such as "(Ethereum) applications can interact with each other on the blockchain, so a library of useful functionality will gradually build up"...
45
votes
4answers
20k views

What is the cost to store 1KB, 10KB, 100KB worth of data into the ethereum blockchain?

Whatever is stored in the blockchain is immutable which means I can fetch this data back in the future. As of today (2016-feb), How does one store a 1kb, 10kb, or 100kb or arbitary data/text in the ...
4
votes
2answers
841 views

What are the ways I can contribute to Ethereum?

I'd like to know more about how to contribute, both on a technical and non technical perspective
5
votes
1answer
376 views

How can we conserve disk space or compress the blockchain?

The blockchain is eating into my macs disk space. Will there be a way in the future to compress it or redirect to an external hard drive?
1
vote
0answers
2k views

As of Feb 2016, how big is the ethereum blockchain size and its monthly growth rate? [duplicate]

As of Feb 2016, how big is the ethereum blockchain size and its monthly growth rate? Does the blockchain implement anything with pruning to reduce its size in the near future?
9
votes
1answer
298 views

What is the utilisation level on the Ethereum blockchain? [duplicate]

How many transactions are currently executed on the Ethereum blockchain and how does this compare to other blockchains?
29
votes
7answers
21k views

What are the differences between Bitcoin blockchain and Ethereum blockchain?

Ethereum has been debated in the bitcoin ecosystem and was criticized. In order to understand better both projects, what are the main differences between BTC and ETH regarding the blockchain ...
23
votes
3answers
9k views

What is a Shard?

Proof of Stake brings new concepts to the Blockchain ecosystem. In the dictionary "Shard" is defined as "A broken piece or fragment, as of pottery or glass".
22
votes
1answer
2k views

What would be needed to store the blockchain as a IPFS object?

In Christian Lundkvists blog post about possible uses for IPFS, he suggests that storing the Ethereum blockchain as an IPFS object could potentially decrease the size of the chain: We see the ...
19
votes
1answer
3k views

This image claims you can build “decentralized apps”, and each computer “contributes a little to process it”. Is that claim correct?

This image claims that you can put decentralized apps (say, a messaging program) on the Ethereum network. It also claims that each computer on the network contributes a little bit to the processing of ...
14
votes
1answer
4k views

What does it mean to “run code on the blockchain”? Wouldn't blockchain become huge?

More technically speaking, what does it mean to "run code on the blockchain"? Does it mean that we store the source code and then every full node runs that source code several times? If, for ...
15
votes
5answers
3k views

What is a blockchain? What is the concept behind it? [closed]

I have been going through some docs, and I understand that BlockChains are mostly like the building blocks in an Ethereum network. So, can someone give a dumbed down explanation/definition about what ...
10
votes
1answer
690 views

Why are contracts limited to only the previous 256 block hashes?

Why are contracts limited to only the previous 256 block hashes using the BLOCKHASH opcode (and corresponding functions in Solidity and Serpent)? Why does another contract, such as this, need to be ...
14
votes
1answer
5k views

What Ethereum blockchain explorers exist?

What blockchain explorers exist and What special features do they have? Are they open-source? How reliable are they (approximate uptime in %)? Is there a testnet version?
4
votes
1answer
606 views

Can geth and eth share the same accounts and blockchain?

It appears when I have multiple ethereum clients installed, that they all have their own data, accounts and even their own copy of the blockchain. Is it possible to share accounts and the blockchain ...
2
votes
1answer
310 views

How will the number of confirmations for security change with Casper?

How will this answer change when Casper is deployed?
56
votes
6answers
74k views

What number of confirmations is considered secure in Ethereum?

In Bitcoin, 6 confirmations are considered secure (very low probability of transaction/block reversal). What is the current number in Ethereum?
41
votes
4answers
19k views

What exactly is an Ethereum client and what clients are there?

Ethereum.org's introductory Command Line Interface tutorial mentions these clients: eth - a C++ client suitable for mining, IoT and contract development geth - a security audited Go client for use ...
75
votes
6answers
50k views

Ethereum block architecture

Where can I find a description (preferably a diagram like below) showing the block structure in an Ethereum blockchain? Credits: Wikipedia
13
votes
3answers
2k views

Is there a functional equivalent to Factom in Ethereum?

Factom is a distributed data and records management and audit system. How easily can what Factom does be done in Ethereum? Are there any working DAPPS doing this? Could a simple smart contract take ...
13
votes
1answer
3k views

What is state-trie pruning and how does it work?

Several sources mention the idea of state-trie pruning. What is that, and is it currently being implemented on the network? Is this a manual process or can it be done automatically? If Ethereum is ...
156
votes
7answers
115k views

What are the Ethereum disk space needs?

How fast is Ethereum blockchain growing and how big is it likely to get in the future? Is it still about 1 GB per month? Are there any data pruning or compression algorithms in place?
28
votes
3answers
13k views

How to create a Dapp from scratch on Ethereum?

Let's say we have someone who knows about blockchain but who doesn't have any background in blockchain-based application. That person wants to code an ethereum-based Dapp (decentralized application) ...
102
votes
11answers
80k views

How would I explain Ethereum to a non-technical friend?

I've recently attempted to explain Ethereum to several non-techy friends. My explanation usually involves starting with a comparison to Bitcoin, but this quickly becomes complicated as I then have ...
91
votes
5answers
22k views

How can a contract run itself at a later time?

In my blockchain application, I would like to have an event triggered at a later time, hours or perhaps even days after the application has most recently received a transaction from a user. How can I ...
71
votes
3answers
20k views

What is an uncle/ommer block?

The Ethereum blockchain is described as containing "ommer" blocks, usually called "uncle" blocks by the general public. What is an ommer/uncle block, and why are they needed?
9
votes
3answers
654 views

How do smart locks make sure that they have access to an up-to-date version of the blockchain?

Smart locks like Slock.it are supposed to allow locks to be able to do things based on the blockchain state. Does that work with locks that don't have their own internet connection? If so, how does ...
8
votes
2answers
1k views

What are the trade-offs between Ethereum's public chain and private, permissioned chains?

I see a large number of news stories and companies talking about the possibilities for private or permissioned blockchains. What are the key tradeoffs between using a permissioned/private chain and ...