Matt Tyndall tyndallm

ETH 2.0 concept Go client

Initial design doc for a new Go client for ETH 2.0. By @protolambda.

Hope the ideas and outlined problems help design the ETH 2.0 successor of Geth ("Firefly"? See F.A.Q.).

This is a starting point for a work-doc for initial contributors, some of the goals may still change.

Analysis of Casper PoW Reward Reduction

EIP 1011 - Hybrid Casper FFG proposes further reducing PoW block reward from 3 ETH to 0.6 ETH. The EIP briefly mentions that this is "because the security of the chain is greatly shifted from PoW difficulty to PoS finality and because rewards are now issued to both validators and miners." This document is to serve as an addendum to that statement, providing additional data, analysis, and arguments.

We aim to show that in Hybrid Casper FFG with an 80% reduction in block reward:

a PoW attack on the finality enabled chain cannot do much in comparison to a pure PoW attack
a pure PoW attack just as costly as other prominent PoW chains
there are options in the event of an attack
all of the above is a strong discouragement for an attack to be conducted in the meantime before full pos

Answers to Deep Questions about Solidity

The following list of questions was taken from https://www.reddit.com/r/ethereum/comments/72reba/do_you_have_deep_questions_about_solidity_or_the/

An updated summary on the different ways one could have two contracts interact (DELEGATECALL, STATICCALL, libraries, all that stuff) with clear pros/cons for each (gas cost, whether it requires EVM assembly directives, etc)

Question by /u/drcode

I won't talk about low-level opcodes here because of the brevity of the answer. In general, there are four ways functions can be called in Solidity:

This gist shows how formal conditions of Solidity smart contracts can be automatically verified even in the presence of potential re-entrant calls from other contracts.

Solidity already supports formal verification of some contracts that do not make calls to other contracts. This of course excludes any contract that transfers Ether or tokens.

The Solidity contract below models a crude crowdfunding contract that can hold Ether and some person can withdraw Ether according to their shares. It is missing the actual access control, but the point that wants to be made

	module.exports = {
	promisify: function (web3) {
	// Pipes values from a Web3 callback.
	var callbackToResolve = function (resolve, reject) {
	return function (error, value) {
	if (error) {
	reject(error);
	} else {
	resolve(value);
	}

	// This is a simple NodeJS app to display triggered events on a smart contract
	// you need your contract ABI and deployed address and also a synced geth running
	// github.com/shayanb

	var optionsABI = [YOUR_CONTRACT_ABI]
	var contractAddress = "0xYOUR_CONTRACT_ADDRESS"



	var Web3 = require('web3');

	contract AmIOnTheFork {
	// Tracks whether hard fork is effective on this chain. True means the fork is passed, false it hasn't.
	bool public forked = false;

	// Dark DAO address
	address constant darkDAO = 0x304a554a310c7e546dfe434669c62820b7d83490;

	// This function should be called between block 1920000 and 1921200.
	// Approximately between 2016-07-20 12:00:00 UTC and 2016-07-20 17:00:00 UTC.
	// After that the status will be locked in.

	express = require("express")
	request = require("request")
	BufferList = require("bufferlist").BufferList
	app = express.createServer(express.logger(), express.bodyParser())
	app.get "/", (req, res) ->
	if req.param("url")
	url = unescape(req.param("url"))
	request
	uri: url
	encoding: 'binary'

	var express = require('express'),
	request = require('request'),
	BufferList = require('bufferlist').BufferList,
	sys = require('sys');

	var app = express.createServer(
	express.logger(),
	express.bodyDecoder()
	);