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1500 questions
42
votes
3 answers

How does the Casper proof of stake algorithm work?

Ethereum plans to move to the Casper proof of stake algorithm in a future version of the network. What are the details of that algorithm, and how does it compare to previous Proof of Stake consensus protocols?
Jeff Coleman
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41
votes
5 answers

Convert address to string

In Solidity, how can I convert the sender address to a string? The comments in How to convert an address to bytes in Solidity? did not provide a working solution
nick carraway
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41
votes
10 answers

How can I find out what the highest block is?

I'm syncing up a new node. How can I find out what the latest block is so that I know how far I've got to go?
paulmorriss
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41
votes
5 answers

How can I run go-ethereum as daemon process on Ubuntu?

The Installation Instructions for Ubuntu suggest running geth from the command line, how can I run it as daemon process / service on Ubuntu?
J-B
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41
votes
5 answers

How to detect if an address is a contract?

I'm interested in knowing whether any particular address is a contract address or a standard address. There have been similar questions on the topic, but I'm not looking to detect whether an address is valid as this is child's play. I assume…
Sandwich
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41
votes
2 answers

Deploy contract from contract in Solidity

It's a common pattern to use a hub/factory contract to create multiple instances of a standard contract. It's also common to require a way to enumerate the addresses of the created contracts. Is there a simple minimal example of a good approach?
Rob Hitchens
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41
votes
1 answer

How to Mine Ether and use Ethereum on Windows?

Which programs should be installed and what do you need to do to start mining Ether and use Ethereum?
user75798
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40
votes
5 answers

How can I store data in ethereum blockchain

I want to store pdf hash in blockchain I already read this post What are some proposed ways of storing data in Ethereum? But I'm beginner in this domain and I don't understand... Is it possible to store data (hash in my case) in Ethereum? How many…
wxcvbn
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40
votes
2 answers

How do I convert my The DAO tokens into ethers using the withdrawal contract after the hard fork?

The DAO contract was attacked on 17th June 2016 where the attacker drained about USD 50 million worth of ethers using a recursive call vulnerability in The DAO contract code. The attacker drained the stolen ethers into a few child DAOs and the…
BokkyPooBah
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40
votes
4 answers

Error: account unlock with HTTP access is forbidden when unlock an account in Geth console

personal.unlockAccount(eth.accounts[0],"") Error: account unlock with HTTP access is forbidden I run Geth in a Docker container and use docker exec -it bootstrap geth --datadir=~/.ethereum/devchain attach to exec the Geth console.
Wayne
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40
votes
8 answers

Where are my keys and chain data located if I am using Parity?

Switched from geth to Parity and wondering where my information now is. Thanks.
tayvano
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40
votes
3 answers

Can a contract safely rely on block.timestamp?

How safe is it to use block.timestamp as contract expiration time? If a miner provides an incorrect timestamp in a block header, how much can it be off before it is rejected by other nodes? Is there a strategy to make a contract more robust to this?
J-B
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40
votes
2 answers

How do I detect a failed transaction after the Byzantium fork as the REVERT opcode does not consume all gas?

Pre Byzantium fork, I could use gas == gasUsed to detect when a transaction has failed (further details in How can the transaction status from a thrown error be detected when gas can be exactly the same as the gasUsed for a successful…
BokkyPooBah
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40
votes
3 answers

What does it mean that Ethereum is "turing complete"

People often say that Ethereum is a "turing complete" blockchain, or that it comes with a built-in "turing complete" programming language. What does this mean, and why is it an important feature for Ethereum?
Josh Stark
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40
votes
2 answers

What exactly is the Nothing-At-Stake problem?

What exactly is the Nothing-At-Stake problem in Proof-of-Stake consensus networks? While I understand what the nothing at stake problem means, I do not really understand the security implications. What are they?
q9f
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