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.

385 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6
votes
1answer
685 views

Block header structure change under Proof of Stake?

The yellow paper describes the below block header structure: This includes difficulty, beneficiary, mixHash and nonce values. Presumably these will be redundant under Proof-of-Stake. How will the ...
5
votes
1answer
796 views

Call write function, which doesn't change contract value

I'm new in smart contracts and faced with one problem. After deploying contract to my test local blockchain network, i try to set new value via setter, after that I call get method of contract and it ...
4
votes
0answers
345 views

What is the current size of the Ethereum State?

What is the current size of Ethereum's state in bytes? I am not asking about the size of the blockchain with blocks headers, transactions and receipts. I am looking for the size of all the structure ...
4
votes
1answer
424 views

Storing private data off-chain with a sharing feature upon request

My question is not very technical from an implementation point of view, but I am looking for advice to achieve a specific use case using blockchain tech. I would greatly appreciate any insights or ...
4
votes
1answer
324 views

Why does geth -light start importing block headers from 3297471

I've been using geth to download the blockchain (on full) and one of the requirements for my research involves the use of light clients. I used 2 computers to download the blockchain on the -light ...
4
votes
0answers
111 views

Did the ripemd precompiled contract get deleted?

A bug "caused account 0000000000000000000000000000000000000003 to be deleted in block 2675119, even though the deletion should have been reverted due to an out of gas error." Source Did account 0..3 ...
4
votes
0answers
131 views

Genesis.json permanence and updating the blockchain

I understand that the initial genesis.json attributes are a permanent thing, and it cannot be changed retroactively. But what I want to know is which parameters are changeable afterwards and how? ...
4
votes
1answer
132 views

Can someone share your geth export file with me?

I need to setup an archival node ASAP but the download takes around 1-2 block per second. With this speed it will finish in 2 months (if it doesn't stall, but it does, I have to restart it manually ...
3
votes
0answers
74 views

Zero Knowledge Range Proofs

I am new to the world of Zero Knowledge Range Proofs. I read the following on GitHub: https://github.com/ing-bank/zkproofs The Zero Knowledge Range Proof allows the blockchain network to validate ...
3
votes
0answers
158 views

What filesystem should I use for geth and leveldb?

I used old LGA775 machine for running geth node. Its mobo has older sata 3gb/s (benchmark showed that ssd bottlenecked there) and only 4gb of DDR2, with windows installed. So syncing is a real pain ...
3
votes
1answer
64 views

Understanding what happens between transaction creation and block creation in Proof of Authority

I am currently writing my thesis where I'm investigating the potential of blockchain technology to become the underlying technology in a system that is create and record qualifications. I'm at the ...
3
votes
0answers
192 views

How to access txpool pending transactions using Netherum?

I want to get list of transactions which are in pending state & queued state in txpool. I can see these transactions in pool using txpool.inspect command. I tried code given in nethereum sample ...
3
votes
0answers
1k views

Mining hangs on Generating DAG in progress

I am trying to initialize rpc using the below command and start miner using miner.start(1); geth --rpcapi eth,web3,personal --rpc --networkid=15 Mining starts successfully with below logs but it ...
3
votes
0answers
106 views

Parity create testing transactions and blocks

For test purposes, I would like to make test blocks including test transactions against main net. For example I would like to make a transaction that sends one ether from 0x1234567... to 0x99999999......
3
votes
1answer
206 views

Uncle blocks in Parity PoA blockchain

As I know that there is no competition for mining new blocks in POA blockchain as each node mines new block at its given time slot. I have a parity PoA blockchain setup with 5 nodes. While examining ...
3
votes
1answer
640 views

geth - admin,addPeer() and static-nodes.json don't work

I'm trying to connect two nodes (both miners) on my private network. They are based on the same VM in different data directories. They have different ports and are based on the same genesis file and ...
3
votes
0answers
308 views

SSL Support for Communication Between Geth Nodes

We are using private Ethereum network for a multi entity use-case. The problem is that all these entities geth nodes sits behind a firewall which only allows TLS traffic. The node that's broadcasting ...
3
votes
0answers
1k views

How to encode data payload in ETH transaction

I'm using python to sign and send ETH transactions, and would like to do the same for ERC-20 token transactions as well. I'm having trouble correctly encoding the data payload to invoke the transfer ...
3
votes
0answers
439 views

How can i confirm transaction in geth from other peer of blockchain?

I have a query , I have create a private blockchain in which one geth node1 is use for transaction taking and other one(node2) is for mining .They are peered with each other and perfectly ...
3
votes
0answers
142 views

Geth bus fatal error

My geth node (v1.4.18 on testnet) has unexpectedly go down throwing an error like this: I1028 04:46:29.305710 ethash.go:259] Generating DAG for epoch 44 (size 1442839168) (...
3
votes
0answers
188 views

Blockchain compression Suggestions

I am planning to do a course project on block chain compression so that network transfer time is optimized. I read somewhere that the EVM bytecode component of the blockchain can be compressed. Is ...
3
votes
0answers
139 views

Updated geth, now I am re-syncing the whole blockchain

This is the first time I have updated geth. I was at a build of geth from several weeks ago, and this morning I updated to 1.4.12. I downloaded the pre-built binary to a new location on disk, ...
2
votes
0answers
34 views

Confidential data encryption on blockchain

I already built a supply chain that is able to collect product information on Ethereum. Now, that data can be confidential, but I still want to do Matrix calculations on it. I came across homomorphic ...
2
votes
0answers
22 views

How can I test a consensus protocol that I created?

Currently, I am designing my own blockchain consensus protocol and I want to test its performance. Is there any available tool or well-known framework that gives me this ability?
2
votes
1answer
37 views

Blockchain overhead - general question

I was reviewing the blockchain technology the other day, Maybe this is not the right place or maybe I should rephrase my question but.. Blockchain is peer to peer, every peer stores the data Data is ...
2
votes
1answer
56 views

How to download the blockchain of a single ethereum contract’s address?

The blockchain required to run ethereum is several Terabytes large. This means more than 9 years would be required to download it with my connection speed. In my case, I just want to know if the ...
2
votes
2answers
23 views

How can I find the block where a user enacted a certain event on a contract?

I'm trying to build a web3.py program to take in a given user's address, and return the amount of ETH traded since they added liquidity to a Uniswap exchange. Uniswap is a smart contract on the ...
2
votes
1answer
25 views

Etherescan Unique Address Growth Chart - How is it computed?

how does Etherscan get this information from the blockchain? Is it possible via using a web3 module? Any insight? https://etherscan.io/chart/address
2
votes
0answers
14 views

I am sending some ether from account[0] to account[1] using geth console. But the amount is not getting added to the receiving account

I tried to mine the transaction using miner.start() command, still account balance remains the same > miner.start(8) I0428 16:27:15.927553 miner/miner.go:136] Starting mining operation (CPU=8 TOT=...
2
votes
0answers
51 views

Automatic sign of Transaction

Is there any secure solution(without exposing a Private key of the user) to automatically sign transactions, which are requested from a DApp, so that user doesn't have to sign each of them manually? I ...
2
votes
0answers
512 views

How Merkle trees are implemented in a database exactly

I have just checked out these resources: What is a Merkle Tree? Beginner’s Guide to this Blockchain Component Using Merkle trees to detect inconsistencies in data Exploring the use of Hash Trees for ...
2
votes
1answer
91 views

How can I execute transferFrom function in node js

There is solidity erc865 code function transferFromPreSigned( bytes _signature, address _from, address _to, uint256 _value, uint256 _fee, uint256 _nonce ) public ...
2
votes
0answers
147 views

Gas estimation failed

whenever I want to run this code I get this error "Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending? VM ...
2
votes
0answers
50 views

Transactions are not mining for accounts created by Nethereum.Accounts.Account method but works for accounts created by web3.Personal.NewAccount

Transactions are not mining & in pending state for long time, for transactions with accounts created using Nethereum.Accounts.Account(privateKey). But mining works for accounts created using web3....
2
votes
1answer
86 views

In what way does Sharding allocate transactions for each shard? state? or node selection?

In what way does Sharding allocate transactions for each shard? I know that accounts are assigned to each shard based on prefix in the account's address and each shard processes the transactions ...
2
votes
1answer
57 views

How to increase stored block states from 128 to 10 000 in Geth?

AFAIK Geth preserves states for the last 128 blocks by default. I would like to keep states for, say 10000 blocks (not turning myself into archive node). Is it possible?
2
votes
3answers
279 views

Does Using Infura Breaks Decentralization?

Decentralized applications have a philosophy: they are immutable,secure and trustless applications. You can connect to Blockchain and be sure about that features. Infura is a great tool when ...
2
votes
1answer
41 views

Are there any forks or alternate flavors of Ethereum that allow cross-chain swaps between two EVM-like chains?

I’d like to run an alternative consensus protocol based on the geth client. Since geth already has a ton of consensus protocols, I was wondering if any coins on the market were able to do the ...
2
votes
0answers
44 views

can raiden network be used on ethereum PoA(proof of Authority)?

https://github.com/raiden-network/raiden can raiden network be used on ethereum PoA(proof of Authority) ? If it can , how to use it? Please help.
2
votes
1answer
380 views

How to change block generation period?in POA private ethereum blockchain

my genesis.json like that: "config": { "chainId": 333, "homesteadBlock": 1, "eip150Block": 2, "eip150Hash": "0x0000000000000000000000000000000000000000000000000000000000000000", "...
2
votes
0answers
143 views

Who created this alt-Ropsten blockchain and why?

I usually test on Rinkeby, but this week I have to test some mining stuff, so I tried to get synced up with Ropsten. Unfortunately, after 3 days of trying, I still haven't had any success. The main ...
2
votes
0answers
152 views

Can not access quorum's contract from webpage *CORS*

I am getting following error on browser's console while accessing contracts. Failed to load http://localhost:22000/: Response to preflight request doesn't pass access control check: No 'Access-...
2
votes
0answers
572 views

Hyperledger Fabric and Ethereum Blockchain Integration

How can I connect Hyperledger Fabric to the ethereum blockchain so as to make payments. I am recording the number of tokens to be alloted in the hyperledger system I want to access the data and then ...
2
votes
2answers
408 views

How to check if blockchain is downloading correctly or not?

I've few questions: 1) How to check Eth chain is downloading or not? 2) Does chaindata folder contain the whole blockchain? 3) How to check if blockchain downloading is completed? 4) After ...
2
votes
1answer
169 views

State tree diagram with real world ethereum transaction

Newbee here. Just getting used to StackExchange interface and protocol. Apologies up front for any feeling of misgiving. Would anyone be able to provide an ethereum state trie diagram depicting how ...
2
votes
0answers
123 views

Ethereumjs: How to save the blockchain / state

Ethereumjs noob here. Using the code below, I'm able to create a new blockchain and add blocks to it. But the blocks are not being saved to the database. var blockdb = levelup("./blockdb", {...
2
votes
0answers
98 views

Importing wallet into Mist using custom datadir

I'm having an issue that seems to be quite common but I haven't found a solution. I'm using Ethereum Wallet 0.9 and I have all the application data, including the blockchain on an external drive. When ...
2
votes
0answers
137 views

Read function returning blank array in geth

I have deployed a smart contract on geth which has 2 simple read, write functions in it. Then I called the write function; e.g. payment.place_order("Laptop", 10,{from:eth.accounts[0]}). After the ...
2
votes
0answers
481 views

Geth always returning a 0 balance?

i´m mining now for about 3 days with 3 rigs each with over 50Mh/s, but my balance is still 0. Does anybody know why ?
2
votes
0answers
164 views

Deploy Button is not responding

I am newbie to solidity, this is my first PoC on testnet, i am just trying to understand how things works. i am following the main tutorial on Ethereum website, under this URL https://www.ethereum....

1
2 3 4 5
8