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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.

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Incorrect Usage. flag needs an argument: -rpcaddr = Ethereum private blockchain

I'm trying to make Ethereum private blockchain. But facing a error while running this "geth --nodiscover --networkid 42 --datadir .ethereum/ --unlock 0x526d8a6baa472da27215f748236af96bc9f256d7--mine ...
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1answer
33 views

Is there any period of custody for block rewards in Ethereum?

In Bitcoin, some block heights are required for spending coinbase transaction. But in Ethereum, there's no input/output. Then, is there any maturity time for using block rewards in Ethereum? If yes, ...
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2answers
32 views

What is meant by locking of ether in proof of stake?

In PoS, forgers stake their ether on a block. These ether are locked and can't be used. What does it mean by locking of ether and how does it work?
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1answer
129 views

Invalid sender when sending Raw Transaction, signed w/ ethereum-tx on PHP

I am using PHP and ethereum-tx library https://github.com/web3p/ethereum-tx to sign transactions but when trying to send them to the node I got an "invalid sender" error. Besides, exactly the same ...
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0answers
35 views

Ethereum Blocksci parser tool

I need a blocksci parser for ethereum. I am using https://github.com/citp/BlockSci for bitcoin . Is any similar blocksci parsing tool for ethereum?.
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0answers
26 views

When locate a block with both the hash and block number?

In the go-ethereum code, I see functions use both the number and block hash to locate a block. Why is that? Isn't block hash enough? An example function: https://github.com/ethereum/go-ethereum/blob/...
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3answers
47 views

Blockchain flow in food industry [closed]

I am trying to learn blockchain by doing small projects. I was able to complete a small project in blockchain for cryptocurrency using c#. Now, I am trying to understand the flow of a blockchain in ...
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0answers
22 views

simulation or performance evaluation with Ethereum testnet

I was if you could help me about simulation. How can I simulate the performance of my following IoT-based Application with Ethereum testnet? In my senario,there are some nodes that store sensor data ...
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1answer
111 views

Cloning geth and adding a POS consensus algorithm? [closed]

I am currently learning how to use geth, so far I was able to create a private POW and POA blockchain using one of its consensus types (Clique). I am wondering how feasible it would be to clone the ...
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1answer
66 views

ERC 721 card game

The general concept of ERC 721 is clear to me. My question is more about the contract deployment. I want to have 100 unique cards, So I thought of these two implementations: Having an initial supply(...
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0answers
25 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....
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1answer
51 views

create multiple transactions between two accounts using SendTransactionAsync method nethereum

I am trying to create multiple transactions between two accounts using SendTransactionAsync method. But I am getting "replacement transaction underpriced" message. I found some links which says we ...
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2answers
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Will a transfer go through on a testnet transaction on meta mask to luno

What if you sent your ETH on the Ropsten testnet via Metamask to an ETH platform gateway like Luno (https://www.luno.com) ? Will you receive your Ether and will it reflect on that account? I've done ...
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1answer
50 views

How to limit latest block in Geth

I need some test Ethereum blockchains for development purposes. I need only part of blocks synced for example, blochain synced from 0 to 10'000`th block, because for example Rinkeby synced in archive/...
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1answer
134 views

Creation of test network using ganache

Can we reuse the values stored in the ganache test network which is running in the local machine, even if the terminal which is running ganache test network is closed or what are the possible ways to ...
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0answers
83 views

Questions with Building a dapp using Quorum [closed]

I am working on a project to build a dapp for a trust system using Quorum, which needs a permissioned blockchain for data privacy. Only the admin, beneficiary, caregivers, case manager and authorized ...
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0answers
28 views

Read args object from particular block transaction in truffle console.

Hi I have question on how to read args from specific block transaction that are passed when event was called. I have triggered an event, my block is created and i got transaction tx. In the ' Logs: ' ...
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1answer
51 views

Ropsten Ethereum not showing transaction information

I am using geth 1.7.3-stable-4bb3c89d to sync with Ropsten network. I started synchronization with fast mode and restarted the service. When I type eth.syncing in geth console it always shows false ...
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1answer
314 views

web3 not connecting to Infura / Rinkeby Testnet

I've successfully deployed my Smart-Contract to the Rinkeby TestNet via Remix. Everything works perfectly from within Remix. But when I try to get my web DApp to fire methods in my Smart-Contract - ...
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1answer
116 views

What does Error: Provided address “1.2870172725867908e+48” is invalid, the capitalization checksum test failed

I have assigned my variables here > var contractAddress = 0xb5A5F22694352C15B00323844aD545ABb2B11028 > var cont = new web3.eth.Contract(abi, contractAddress) I am getting the error : ...
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1answer
120 views

difference between return and returns

contract Helloworld { uint private simpleInt; function getValue() public view returns (uint) { return simpleInt; } } What is the difference between "return" and "returns", I am a ...
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2answers
56 views

Solidity can't modify block.timestamp due to lvalue xpression

I have a problem regarding modifying block.timestamp. I would like to modify timestamp in my network and change block.timestamp to unix timestamp, but I got an error at modification: TypeError: ...
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3answers
64 views

What is Metamask?

I know it's a dApp web3 browser, a wallet. But which ethereum client is used in the back end to interact with block chain? How the same account is able to connect with all networks (mainnet,testnet, ...
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1answer
23 views

Which type of Projects/Apps are suitable/best to be developed in blockchain/dapp technology? [closed]

Which kind of Apps are best to be developed on the base of blockchain/dapp/web3 technology. Suggest me please as I am looking for an advice for an academic final year project.
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1answer
36 views

Contract's transaction count in a certain period

I want to determine the number of transactions of a contract in a certain period. My question is that in the transaction receipt, if we want to say that contract A has x number of transactions will ...
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1answer
14 views

how to fix a fact that the recipient received the file so that the recipient could not dispute it?

how to fix a fact that the recipient received the file so that the recipient could not dispute it? How to do this by a smart contract? thanks in advance.
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1answer
129 views

Unable to interact with DApp deployed on quorum

I am unable to interact with contract using Dapp deployed on Quorum blockchain (using metamask). I am following "https://truffleframework.com/tutorials/building-dapps-for-quorum-private-enterprise-...
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1answer
81 views

Is there a way to prevent any client connected using web3.js to Quorum from deploying a contract?

I am planning on using Quorum for a permissioned setup,Is it possible to prevent anyone having a web client and connected to any quorum node deployed in the network from deploying a contract?
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1answer
41 views

Ideal Blockchain decentralized app [closed]

I want to know your opinions about what do you think the best architecture for building a decentralized application? Taking into consideration the global adoption, and how to avoid telling the users ...
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1answer
37 views

how to deploy dapps into production (mainnetwork) [closed]

i'm newbee as a blockchain developer.I have deployed smart contract into ethereum test network.as part of next step i want to know what are the steps invovled in deploying blockchain at production ...
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1answer
55 views

Use of RPC, IPC and ws in go-ethereum?

RPC provides http-rpc server.But what is the use of IPC and ws?
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0answers
78 views

Same Block Received More Than Once With Same Block Parameters

Use Case: I am implementing a deposit system where I will get a block as it is mined and parse transactions to check for a deposit of Ether or a specific token. Getting the same block twice will ...
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2answers
362 views

How much does it cost to store each IPFS hash in Ethereum blockchain

I've looked in some of the resource on calculating the Gas costs like this spreadsheet I found on this thread. But the spreadsheet only have computations gas costs but not storing of hashing. I'm a ...
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1answer
55 views

Deploying fails with different compile version

I'm trying to implement a simple card game. Actually, everything is working fine. Until I tried to move from 0.4.0 to 0.4.22. Any idea what is going wrong? Thanks a lot. And here the code: pragma ...
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1answer
105 views

Converting int to default block parameter

I am using Infura and web3j to query the Ethereum blockchain. My aim is to get information about certain blocks so i'm using the function web3.eth.getBlockByNumber, however it gives me incompatible ...
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0answers
236 views

Total number of state entries

I am syncing my ethereum blockchain using the default syncmode. I want to know how many total state entries are there because currently the highest block is 6544578 and the number of pulled states i.e....
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1answer
14 views

Is it available to have an application that is managed by single Entity?

If For example Entity A wants to build a smart contract that manage a group of devices. But since each device uses pseudonym and he may change it later, is there any way to build the contract such ...
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0answers
60 views

Not able to Get the response from the function call from Node Js Service Using Web3@1.0.0-beta.36

I am deploying two contracts A and B using Web3(1.0) and solc. My Solidity file looks something like this: pragma solidity ^0.4.21; contract A { uint public value; constructor(uint newValue) ...
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1answer
73 views

Get time when the transaction was included in your node

Is there any way to obtain the time when you have received a transaction? I would like to know when is a Smart contract included in my node. (local testnet)
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1answer
111 views

Ethereum propagation delay

I have a very beginner level question. Suppose I have a list containing the IP address of different machines and I want to share them via ethereum blockchain and suppose that the list is very large as ...
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1answer
30 views

How can I get the records of invalid blocks once have been mined?

As we all know, an invalid block will be ignored and won't be propagated when a verifier finds its invalidity. However, if there is a need to get the records of all invalid blocks once have been mined ...
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2answers
195 views

Quorum 7nodes example unable to attach to geth node 1,2,4,5,6,7 but node 3 is working

Quorum 7nodes example all of sudden gave fatal error unable to attach to remote geth. Problem: can't attach to geth node Every time I import metamask account to geth node (using personal.importRawKey(...
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2answers
29 views

Proper way to design a descentralized game

Let's say I'm designing a multiplayer game, where players can fight each other in different battles. As a result of each battle, players get a punctuation. Suppose I'm using a sidechain. Which should ...
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1answer
227 views

IPFS. Add a directory recursively with an HTTP api

Is there an HTTP api equivalent of doing: ipfs add -r resources/public where resources/public is a directory with a static website (index.html in the root, css, js etc). Doing: curl -F file=...
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1answer
43 views

Can we transfer ethers using a EOS smart contract

Suppose we want to transfer ether from our EOS smart contract. I know atomic swaps is not possible between ether and EOS blockchain, may be in the future but not now. Is there any other ways round to ...
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1answer
163 views

Ethereum gas limit issue while sending transaction from web3 client (private network)

I have setup a private Ethereum system using geth. And am running a client that uses a web3.js file to connect to the Ethereum system. While trying to send a transaction or call some contract function,...
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1answer
46 views

Should I use Node.js server along with ethereum smart contracts to make Dapps?

I want to make a Dapp using ethereum. So, should I use a Node.js server and a database to store some user's data and store rest of the data on the smart contract that needs to be decentralized or ...
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0answers
52 views

What are some fullnode health indicators in geth? (mgasps etc.)

I run a few ETH fullnodes using the Geth implementation, and I'm curious about some of the metrics, specifically mgas, mgasps and how they reflect the health state of the node. Here is the output of ...
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2answers
91 views

How can I store and read data from Etherum blockchain? [closed]

I'm doing a project and I want to store some basic information on Etherum, for example: Name, ID, Height, Weight. How can I store this on the blockchain and after that be availble to read it. I read ...
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1answer
48 views

Retrieving transaction hash in all blocks after fast sync

I have set up an ethereum node using fast syncmode. I want to retrieve all the transaction hashes and the recipient between a range of blocks, let's say 0 - 13000. Will I be able to retrieve the ...