Linked Questions

151
votes
16answers
42k views

How can I securely generate a random number in my smart contract?

If I am writing a smart contract for some kind of (gambling) game, how can I generate a random number securely? What are the best practises and security trade-offs to be aware of?
13
votes
6answers
17k views

Is there a list of DAPPS that are already useable? [closed]

Is there a list of DAPPs that are already useable? Useable means there is an easy accessible GUI, that can interact with the contract.
13
votes
5answers
3k views

What is the difference between a smart contract and a DAO?

The Ethereum space is full of new terminology, and it's sometimes difficult to mentally discriminate between some of the concepts that this new terminology describes. (I'm having this trouble now... ) ...
19
votes
2answers
6k views

Deploying the Greeter contract via the geth CLI is not registering in my private blockchain

I am running a local private Ethereum blockchain using: geth --networkid 60098 --genesis CustomGenesis.json --nodiscover --maxpeers 0 --rpc --rpccorsdomain "http://localhost:3000" --datadir "./data" ...
17
votes
1answer
6k views

How to clear large arrays without blowing the gas limit?

As posted by redditor ethererik in the post GovernMental's 1100 ETH jackpot payout is stuck because it uses too much gas, 1,100 ethers are stuck in limbo because the payout of this GovernMental ...
7
votes
3answers
2k views

What are GavCoins and what is their significance?

Quite simply, what are GavCoins and what is their significance?
8
votes
1answer
12k views

Where can I learn how to develop DApps using the solidity programming language? [closed]

What resources exist to help people learn the solidity programming language and create smart contracts & DApps on Ethereum?
6
votes
3answers
2k views

How can I modify bytes32 result to uint?

I want to separate three last digits of the most recent block header hash and get the result as uint. I can get the answer as bytes32 by this code, but how can I change this result to uint? contract ...
8
votes
1answer
2k views

Documentation On Multisig Wallet in Mist?

Is there documentation related to the built-in multisig wallet contract in the Mist Wallet? I see there are many additional functions in this contract like changing / adding / removing owners etc. ...
2
votes
2answers
596 views

What programs should a beginner solidity developers use?

At this time I write code in the 'Solidity realtime ethereum compiler and runtime' chrome extension. And I test my codes on the main net. Are there better programs or how can I get test ether?
2
votes
3answers
921 views

How to verify Mist's standard multisig wallet using Etherscan tool?

I've found standard Mist wallet contract code, thanks to another answer. I am trying to verify this contract over and over using different compiler versions but verification fails. Can somebody point ...
4
votes
1answer
548 views

Understanding TokenCreator/OwnedToken example from Solidity documentation

Here's the page containing the example https://solidity.readthedocs.io Here are two contracts that are supposed to work together(my questions are below): Here's how I think it works. Please correct ...
2
votes
1answer
721 views

recommended datatype for “data” in ethereum transaction

I am sending data with my transaction by using following way var tx = {from: eth.coinbase, to:eth.accounts[1], value: web3.toWei(1, "ether"),data:web3.toHex("Test Data")} personal.sendTransaction(tx,...
3
votes
1answer
521 views

Understanding SimpleStorage example from Solidity documentation

Just started learning solidity from https://solidity.readthedocs.io. Here's the code I'm trying to understand: My questions: Why does get() function has constant keyword? Is it neccessary to put ...