All Questions

0
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0answers
1 view

Truffle and Ganache - do I need to set the same gas-price and gas-limit in both of them?

Or can I set different values? If I can set different values, then how will they be used in the system (i.e., what gas-price and gas-limit will apply in every transaction that I execute)? Here is my ...
-1
votes
0answers
11 views

Wrong Txfee 10.143 Eth for 0.8 Eth transaction

TxHash: 0x913bbcc78ca3c56cb1531a99c0c5febba427427f322d86f74b52e4647dc558a3 Block #7103411 I made a mistake while I entered Txfee manually and Txfee : 10.143 deducted from my account. My wallet ...
0
votes
1answer
15 views

Tokens are not visible in meta mask

I have deployed my ERC223Token contract in my private blockchain. I have transferred some tokens to my wallet It is showing tokens in my mist wallet and remix as well, but it is not showing tokens in ...
0
votes
0answers
17 views

Invalid implicit conversion from bytes32 to bytes memory requested

Error in given code, Invalid type for argument in function call. return ecrecover(operationHash, v, r, s); And, function sendMultiSigToken (address toAddress, uint value, address ...
0
votes
1answer
10 views

timed commitment using ethereum blockchain

I read this paper: https://eprint.iacr.org/2013/784.pdf that introduces the idea of Bitcoin-based time commitment scheme. In which if the commiter does not open his commitment before a specific time ...
1
vote
1answer
10 views

How to burn non burnable ERC20?

Suppose you received 250 HELLOCoins and you want to burn them. Unfortunately, HELLOCoins uses OpenZeppelin ERC20 which implements the following function: function _transfer(address from, address to,...
0
votes
1answer
5 views

Ethers in a light node

Since a light node makes transactions from a connected full node, does a light node need ethers to make transactions or it uses the ethers from the full node?
0
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0answers
13 views

Algorand Consensus vs Ethereum 2.0 Proof of Stake

I studied Algorand and Ethereum 2.0 Proof of Stake. Algorand seems superior. Why can't public Ethereum adopt Algorand as its consensus mechanism? Algorand Agreement - Super Fast and Partition ...
0
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0answers
10 views

How to use a transfer function from an EOA holding a token to a contract address?

I am using an ERC20 token which is used by a smart contact, EOAs also holds tokens How can I use the transfer function for transferring tokens from the EOA to a different Smart Contract address . ...
0
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0answers
12 views

Is signatures from web3.eth/personal.sign deterministic and a safe to be used as seeds for private keys?

The first part of the question: if I give the same inputs (content and signing address) to the web3.eth/personal.sign, am I correct to expect the signature generated to be the same no matter how many ...
0
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1answer
15 views

How to limit N bytes to value range using Oraclize Ledger-Proof Random Number — unfair raffle

Lets say you have 50 tickets to a raffle. You choose to return 4 random bytes from the ledger proof RNG(https://github.com/oraclize/ethereum-examples/blob/master/solidity/random-datasource/...
1
vote
1answer
18 views

how to get input of time in solidity?

I want to run a session for a product in auction , my product struct contains the time interval we need for being the session of the bidding. While initializing a product, I need to take the input of ...
0
votes
0answers
17 views

Setting up the gas price

I wanted to ask that is there any chance by which i can save a particular gas price in meta-mask so i don't have to maximize it when ever i call a function. I want to save a gas price in meta-mask for ...
0
votes
0answers
31 views

Transfer ERC20 token from a smart-contract

I am facing an issue and I can't figure what's going wrong. It is a very simple scenario: A smart-contract, that implements ERC20 and ERC20Mintable from OpenZeppelin. pragma solidity ^0.5.0; ...
0
votes
2answers
13 views

How to calculate the difference between what was transferred and what was sent / received?

Hi I'm trying to get some clarity as to what the difference is between what was Transferred Sent Received Shouldn't what's transferred and received be the same? Transferred means the amount that was ...
1
vote
1answer
8 views

What to enter for NODE_ENDPOINT on blk.io explorer

blk-io/blk-explorer: https://github.com/blk-io/blk-explorer-free Hi, I'm relatively new to ethereum, and I am having difficulty implementing the blk.io block explorer (for my private ethereum ...
0
votes
0answers
9 views

What should we do if s in the ecdsa signature is greater than n/2?

What should we do if s in the ecdsa signature is greater than n/2? As we all know, in the ECDSA signature of Ethernum, the output s must be smaller than n/2, where s is the signature output and n is ...
0
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0answers
9 views

Can I use a WebSocket client for multiple abigen watchers?

I have question about abigen and websocket. My code is in Go. I'm sending a bunch of transactions using abigen and I'm using abigen to watch each of the transaction and do something when it's mined. ...
0
votes
2answers
21 views

Which ERC standard is suitable for an ICO token to have types?

There will be ICO with multiple cycles... Here, investors can purchase tokens and after a fixed window of 270 days, they can redeem it back. But within this window period, they can transfer tokens to ...
0
votes
1answer
8 views

Error in Forwarder creation in MultiSig Wallet

The following code, function createForwarder() public returns (address) { return new Forwarder(); } gives error, TypeError: Return argument type contract Forwarder is not implicitly convertible ...
0
votes
0answers
11 views

How to find contact with a site? [on hold]

good day, I want information about the site icentyr.co, because I've put in an etheric, and I can not get any information about my money. thanks in advance
0
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1answer
17 views

i want to get data from the transaction hash i tried many codes at last i am getting boxes in the output

1) First, I got the input console.log(web3.eth.getTransaction('0x725fc75264726f409793164e336e7d5ed35df8d2be469a0cc1a3a8cc4756b9b9').then((i) => console.log(i) )); 2) I manually pasted the input ...
1
vote
1answer
15 views

Zero knowledge contingent payment on etherum?

I know that bitcoin supports Zero knowledge contingent payment (ZKCP) , can etherum support such ZKCP Payment ?
1
vote
1answer
38 views

What is the behavior of solc with optimizer disabled?

When enabling the optimizer the documentation of solc tells you that you can choose between optimizing the gas cost at deployment or the gas cost at execution by setting the runs parameter. But what ...
0
votes
1answer
22 views

Error during Testing Contract using Ethereum-bridge for oraclize

I'm getting the following error when I'm trying to test (truffle test) my contract which uses Oraclize API 0.5 to get the ledger random from oraclize (datasource = "random"). I'm using solidity 0.5.0 ...
0
votes
0answers
32 views

Error when executing transfer with sufficient funds

When executing a function which buys a loan from a portfolio (sellPortfolio in the code here), I get the following error: I am using Remix 0.5.2 and I have tried to run this from the Java front-end ...
0
votes
1answer
10 views

Invalid type for argument in function call. Invalid implicit conversion from address to address payable requested

function endSuply() public { require(msg.sender == admin,"only admin can end the token sale"); require(tokenContract.transfer(admin, tokenContract.balanceOf(address(this))),"balance not ...
0
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0answers
8 views

Research Papers related to Mythril, Truffle and ReMix

I have found research papers related to most of the testing tools like Oyente, Gasper, MadMax, Securify and so on but I can't find research papers related to Mythril, Truffle and Remix. Are these ...
0
votes
1answer
10 views

ERC777 granularity rounding error

I'm making a token with ERC777 standard. I've got my decimals at 18, and I want whole tokens, so I set granularity to 10^18. when I try to mint 20 tokens, I get granularity error. So I made a ...
0
votes
1answer
17 views

truffle-contract: Contract has not been deployed to detected network (network/artifact mismatch)

I am running a private network and would like to use truffle-contract to interact with the contracts. Unfortunately it gives me this error: Error: Contract has not been deployed to detected network (...
2
votes
1answer
41 views

Function “is not a function” in Truffle dev

I am not sure why I am being told my function is not a function. I am doing calls as I always do from the Truffle console. pragma solidity >=0.4.22 <0.6.0; contract store { string public ...
1
vote
1answer
18 views

Development lifecycle in building a dapp [on hold]

I was wondering if anyone who has experience in working with Solidity/decentralized applications, could share their development cycle in contrast with normal web/app development? Normally, we would 1)...
0
votes
0answers
35 views

Estimate gas limit without eth_estimateGas method

POA Network (Ethereum Like) blockchain has eth_estimateGas to estimate gas limit but this method does not work in POA Network Sokol (Testnet) blockchain. When i call this method it gives response: { ...
0
votes
1answer
22 views

ethLogFlowable: how to get event args?

I am using ethLogFlowable to subscribe to an event and read the args of the event, in my case an address and a uint256 value. I have followed this answer stackExchangeLink, but I am always getting ...
0
votes
1answer
6 views

POA chain: intrinsic gas too low, contract deployment

I'm trying to deploy my smart contract to a private proof of authority chain with geth, but i always get the following error message intrinsic gas too low This is the JSON RPC request i'm sending. ...
0
votes
2answers
37 views

How to choose between Ethereum, EOS, and TRON if I want to build a dapp? [on hold]

In 2018, Ethereum dapps has $2.6 Billion worth transaction volume in 2018; EOS has $3.45B; TRON has $600M. However, number of transactions on Ethereum is way less than EOS and TRON. Ethereum has a ...
0
votes
1answer
15 views

“The constructor should be payable if you send value” although my address and constructor are already payable

I tried to write a simple contract (deployed on Virtual VM java script on Remix) that send a certain amount of money from an account to the other. I construct my receiver and sender address, and my ...
0
votes
1answer
16 views

How to use soliditySha3 in web3py

I have tested soliditySha3 function with web3js. var msg = web3Infura.utils.soliditySha3("transferPreSigned", mainContractAddress, recepientAddress, tokenAmountWei, transferFee, randomNounce); I ...
1
vote
1answer
9 views

Error when trying to open Ganache on Ubuntu: archive type not supported

After downloading a fresh copy of the latest Ganache and double click to run it, the following error is shown: archive type not supported Versions Ubuntu: 16 and 17 All Ganache versions: for ...
1
vote
1answer
34 views

Does this function send ether from the contract or from the message sender?

Solidity newbie here...: function transfer(address payable to, address sender) public onlyadmin { to.transfer(msg.value); } what I want to achieve is sending from the contract's ...
0
votes
0answers
12 views

VET coins lost in My Ether wallet [on hold]

Ive sent some VET coins to My Ether Wallet (MEW)recently and to my surprise they do not show up in my account. Ive done some research on how to get the VET coins back and apparently I need the ...
0
votes
1answer
25 views

Measuring energy usage of smart contract execution [on hold]

Looking into measuring the energy consumption to me of executing particular smart contracts when mining, any tips on how to go about this?
1
vote
1answer
15 views

Importing in SOLC to deploy smart contract

I don't run an Ethereum framework like Truffle and I want to deploy a smart contract using infura node. The smart contract is very simple: pragma solidity ^0.5.2; import "http://github.com/...
0
votes
0answers
14 views

Where should we actually need to set the token price?

I have seen a video which sets the "token price" in a contract using that token (erc20), If the same token is used in another contact for transferring in another contract with a different value of "...
0
votes
1answer
8 views

How do you add miner address so that it can mint tokens?

I have ERC721 that I'm making. function mint(address to, uint256 tokenId) public onlyMinter returns (bool) { _mint(to, tokenId); return true; } How can I add an address so that it is able ...
1
vote
1answer
13 views

How to improve web3 when importing and stop doing the same task over and over again?

When using web3js, you will automatically have to make file to create an instance of that contract which you will use in your main project to interact with. For example, smartContract.js import ...
1
vote
1answer
15 views

Solidity/Truffle - Suddenly getting TypeError on Migration file

Suddenly getting an error when doing a truffle compile --reset - even though I didn't make any code changes on my Migrations.sol file. TypeError: Name has to refer to a struct, enum or contract. ...
0
votes
0answers
17 views

Automatically collect Etherium on one wallet [on hold]

I have a need to create a smart contract. The task is for the smart contract to perform the withdrawal of the entire balance of ETH coming to several of my wallets to one another my wallet. ...
1
vote
1answer
15 views

Uint256 division in vyper (and solidity)

Floating point division is not supported in solidity as mentioned here: How can I perform float type division in solidity? I want to divide two uint256 numbers and save them as a decimal, retaining ...
1
vote
1answer
27 views

How to search through blockchain?

I m doing project for document verification using blockchain in which we don't have to carry documents everywhere, hash key of block will fetch data of doc from blockchain.I m not getting how to ...

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