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.

377 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
1
vote
1answer
123 views

Is there an explorer like Etherscan for Remix JS VM sandbox blockchain

I created a contract and did some transactions. I would like to explore the transactions in the sandbox blockchain in my brower (Chrome). But the tx hash is not found in the REMIX VM Debugger http://...
1
vote
2answers
642 views

The method eth_compileSolidity does not exist/is not available at Object.InvalidResponse stacktrace

I am new to Ethereum. Trying to run a smart contract. I verified the contract content by running it on online compiler. But I am getting an error at the following line of code. var simpleCompiled = ...
1
vote
4answers
211 views

Mist / Ethereum Wallet question

I bought a very small amount of ETH on coinbase just to try it, and I wanted to create my own wallet to get it out. However, I've been trying to get Mist working for 3 days and it is always stuck on ...
1
vote
0answers
236 views

transaction failed - out of gas (How can i return my ethereum and cancel Transaction)

How can i return my ether and cancel this transaction.?? and Ethereum will be return back fund Cryptopia right..?? Transaction link: 0x0991adfb4e316c920f32365b8949e46ae741c055547257e848c6fe92aa308757 ...
1
vote
1answer
74 views

Would this make sense as a smart contract application? Trying to understand features and limitations

I'm starting to read up on Ethereum and smart contracts and some questions are popping up in my mind. I can understand that smart contracts can be used, for example, to make a bet for/against the ...
1
vote
1answer
154 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 ...
1
vote
0answers
150 views

State channel implementation

Say I have a data chain, a party is moving data to a party and so on and so on, and I'd like to trace exactly what party touched what data (given my data has an ID). I wouldn't like to store this on-...
1
vote
1answer
159 views

Python state channel client

Stumbled upon this piece of Solidity code which is an Ethereum payment channel : https://github.com/mattdf/payment-channel How am I to write a Python client that interacts with it over Web3 ? What ...
1
vote
0answers
76 views

Can't deploy contract as I can't input value into “FROM” field

I'm trying to deploy contract through ethereum wallet . But I can't input value into the FROM field . What should I do?
1
vote
2answers
553 views

How to connect peers which are on different computers in geth on private network?

I am trying to setup a private network and trying to connect peers. Currently I'm trying it on my laptop and virtual machine(VM) runing on the same laptop (both of them are connected to internet). I ...
1
vote
0answers
188 views

What is the physical location of Blockchain?

Hello everyone i am new in this technology and i am confused please clear my few doubts. Thanks in advance. Blockchain consist of Blocks but where these blocks are stored, i mean what is the physical ...
1
vote
0answers
289 views

Build secure private ethereum blockchain with geth!

I have read on the StackExchange how to build a private blockchain in LAN with private IPs and geth clients. As I understood to communicate in lan the geth peers need for P2P communication the form ...
1
vote
1answer
283 views

Ethereum Solidity smart contract code Input Output Testing

I have written a solidity based smart contract. I need to test the code on web browser and mobile app. Please suggest the steps what I should do to test and execute the code on - Web browser:- I am ...
1
vote
0answers
113 views

Anyone hitting the blockchain with Go?

I'd love to switch from JS to Go on our back-end, but the constant development of web3 is such a boon. I can see some web3 wrappers for Gopherjs, and of course it's easy to do direct RPC calls with Go,...
1
vote
0answers
233 views

Homomorphic Secret Sharing

Speaking of Ethereum blockchain, Is it possible to perform homomorphic secret sharing algorithmic calculations like SSS/pVSS/VSS on-chain? or should this be calculations performed off-chain
1
vote
0answers
78 views

Will Dapps in production be able to buy and use SaaS solutions?

SaaS services help centralized organizations or apps solve their business problems. For example, Google Apps offers startups as an easy solution for company email and document storage. The sales ...
1
vote
0answers
45 views

Would this three address Ethereum transaction be possible through Geth?

I would like to store an amount of Ether in an specific wallet, likely a wallet generated in Geth. From there I would like to send the correct amount of Ether, I suppose in the form of Gas, or ...
1
vote
0answers
43 views

Is there a way to halt a transaction from being confirmed until an event occurs?

For example, user 1 sends a transaction to user 2, but that transaction is not able to be confirmed until an event occurs, allowing the transaction to be confirmed and thus sent into user 2's wallet. ...
1
vote
0answers
319 views

DB - How do I roll back to a block height?

I was informed on this post that I was, indeed, on a fork. My client starts syncing and encounters a discrepancy with my local DB copy. My peers then vanish. In my case, it would be a great hassle if ...
1
vote
0answers
33 views

I have token in eth I'd 0x5ae3876e3f26b6c99895b1ff9e094e6e6992b88b

Please help how can I transfer my tokens from 0x5ae3876e3f26b6c99895b1ff9e094e6e6992b88b to my another eth wallet account at 0xfdC1049162dd014AF7Fb11099DAe8F2A09f330e2.(both are my wallet ids). But ...
1
vote
0answers
225 views

Event log history is not getting generated ropsten test network

I want to view event log history in my html screen. But I am getting below error in console. Can any one please look into this. I am new in blockchain and this is the first blockchain code I am ...
1
vote
0answers
250 views

Local ethereum node contain two different blocks but with same height

I am using geth node and found 2 different block with same number eth.getBlock("0x162ae4b189f77ed65d0be270aa8dea08d4e7dcd70432a7d1fd4e6b0fb1b301d6") { difficulty: 1001546728, extraData: "...
1
vote
0answers
59 views

How do I verify the integrity of my local chainblock data?

If I suspect local data corruption, is there a way to verify that my blockchain data is valid and will not affect my Ethereum work and transactions? Example: I switched to a self-compiled version of ...
1
vote
1answer
655 views

What is the best parity configuration to run a full archive node on raspberry pi?

I am using a raspberry pi to download the archived version of the blockchain with parity. I've started parity with parity -d /home/xxx/data/Ethereum --pruning archive --public-node However, the ...
1
vote
0answers
93 views

Ethereum performance when fetching transactions from blocks

I need to fetch the completed transactions from the ethereum blockchain ledger. At the moment I am retrieving individual blocks in order to fetch the transactions using web3.eth.getBlock synchronously....
1
vote
0answers
199 views

Can't open ethereum wallet when blockchain is on my SSD

After a lot of searching I found how to set the datadir path to download the blockchain on my SSD instead of my :C/ drive since that's almost full and now that it's downloading the blockchain i would ...
1
vote
1answer
127 views

iOS node not syncing with private BKC

I use the Geth framework and Swift 4 to boot a node inside an iOS 11.0 app. This node connects to my local BKC (to 4 nodes to be precise). Here are some tests I made : if I start 3 computer nodes ...
1
vote
0answers
97 views

Setting balance to an account

After i created a wallet for a user i want to modify his balance, how could i do that without setting the account address' balance in the genesis, I'm using quorum blockchain with web3j. Thank you!
1
vote
1answer
62 views

liaison entre web3 et nodejs [using web3js and nodjs]

Bonjour, j'ai développé une app avec nodejs et je voulais la transférer vers une dapp en intégrant le web3 librairie. En effet j'ai crée les smart contract il le me reste juste la façon de faire la ...
1
vote
0answers
113 views

How to test forked block on local machine?

Read this article How can I reliably induce a blockchain fork for testing purposes?. Example from that thread is outdated, and need to be refreshed. First my step is create initial chaindata from ...
1
vote
0answers
26 views

Use-Case: building a small test-network, did I got it right?

I've to implement a simple use case and I'm not really sure if I understood everything correctly. What I'm trying to do is to build up a network with a few Raspberry-Pi's, running as full-nodes. ...
1
vote
0answers
175 views

How to configure Azure STRATO Blockchain LTS with Visual Studio?

I'm learning all about Blockchain but I wanted to make an example of smart contract, i followed this tutorial, but I can't find much about how to integrate Azure Strato Blockchain with my application ...
1
vote
0answers
205 views

Ethereum raw data files folder

Where is the folder on Mac OSX where Ethereum put raw blockchain data? I find only *.ldb files, but as I understand it is only the index of full database. For example, in Bitcoin there is blk*.dat ...
1
vote
2answers
337 views

Smart Contract - Update implementation using a Relay with delegateCall

I know that smart contracts are supposed to be immutable and that's the whole point, but to expect someone to implement a logic that never changes (no upgrade or no bugs) from day 1 is also ...
1
vote
0answers
234 views

Parity scheduled transaction stuck at submitting

I scheduled a transaction for the BAT token after block 3798640. It remained pending before the block for hours, then submitted about an hour ago, see Tx local viewer screenshot. Anyone know if this ...
1
vote
0answers
245 views

Is there any benchmark about the speed of blocks search engines?

I want to know the performance of search engines such as blockchain.info, smartbit or blockr.io I know that they are very speed but I want a real benchmark that gives the actual speed (in seconds or ...
1
vote
0answers
100 views

What is a sealer and what is the difference between Ethhash, NoProof and BasicAuthority sealers?

Default sealer in cpp-ethereum is NoProof: https://github.com/ethereum/cpp-ethereum/blob/43bae2c78e2a968ef4eb37bec2da4d9b85fa2392/libethcore/ChainOperationParams.h#L73 But I don't understand what is ...
1
vote
0answers
195 views

Ethereum usage for financial transaction

I am new to ethereum blockchain, and i have following scenario of simple money exchange to be implemented: Consider three account Sender(USD), Receiver(EURO) and Provider. Where provider is account ...
1
vote
0answers
266 views

private Ethereum Network Uncle Mining: blockchain forked from a node even that node still connected to the network

I have a private Ethereum Network. It was working without any problems when I had a single miner. But when number of miners increase, I am faced with the following problem: The way I have started my ...
1
vote
0answers
702 views

How to continue to watch the `Events` from the point `geth` was closed?

I have a private Ethereum network. The bootnode(main node)'s goal is to watch Events and if a new Event is generated than trigger a contract's function that I want to run. The key point is triggered ...
1
vote
0answers
1k views

Is my address valid?

I'm using Blockcypher's API (https://dev.blockcypher.com/eth/#generate-address-endpoint )to generate Ethereum addresses. One such address that has been generated is :- Public Address (...
1
vote
0answers
57 views

What do the progress bars on the Alethzero “blockchain download” window mean?

I'm exploring Alethzero. What do the progress bars in the "blockchain download" window mean? I'm seeing this: I'm assuming this relates to the progress in dowloading the blockchain but I can't work ...
1
vote
0answers
268 views

How is transaction finality correlated with transacted amount?

It was argued by Vitalik Buterin that transaction security can be a function of the amount the transaction carries. This is because of the economics of attacks. How many block confirmations would you ...
1
vote
1answer
153 views

Can someone download and run a local version of my contract?

Say I have a smart contract the preforms a specific function and is used in a decryption process off-chain. Would it be possible for Molly to download the entire contract and run it on their own local ...
1
vote
1answer
584 views

problem when deploy smart contract in Quorum using web3j

I'm using web3J when i try to deploy contract i get Error processing transaction request: Non-200 status code: &{Status:400 Bad Request StatusCode:400 Proto:HTTP/1.1 ProtoMajor:1 ProtoMinor:1 ...
0
votes
1answer
17 views

How to match the data in the struct?

If the Set function receives two inputs 1.["0xca35b7d915458ef540ade6068dfe2f44e8fa733c",50,"ROC","park"] 2.["0x14723a09acff6d2a60dcdf7aa4aff308fddc160c",60,"AU","school"] How can I return all the ...
0
votes
0answers
10 views

Can we treat/launch private ethereum chain ethers as a CryptoCurrency in Market?

Warm Greetings! I have a private ethereum blockchain setup on my server with multiple nodes , Also running mining software to mine blocks and earning private ethers (no value in market). Can i ...
0
votes
1answer
20 views

How do I deposit an Ether amount to the smart contract function, namely deposit ? (Metamask version 0.20.7)

I have a problem with using the deposit () function on a smart contract. How do you use metamask 0.20.7 ? const contractInstance = web3.eth.contract(contractAbi).at(contractAddress); contractInstance....
0
votes
1answer
21 views

Two smart contracts interact can't pass value when I using web3.js

I have two different smart contracts interaction_1 and interaction_2 I input the data(team) from remix ide. What I want to accomplish is when user input team in user_input function at interaction_1,...
0
votes
0answers
36 views

How to print the value of a Struct ?(mapping)

If the set function receives two inputs 1.["0xca35b7d915458ef540ade6068dfe2f44e8fa733c",50,"ROC","park"] 2.["0x14723a09acff6d2a60dcdf7aa4aff308fddc160c",60,"AU","school"] How do I display the ...