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István András Seres seresistvanandras

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@alexvandesande
alexvandesande / Random generator
Last active December 23, 2022 09:10
A very simple random generator. A miner can influence the number by not publishing a block with an unwanted outcome, and forfeiting the 5 block reward.
contract random {
/* Generates a random number from 0 to 100 based on the last block hash */
function randomGen(uint seed) constant returns (uint randomNumber) {
return(uint(sha3(block.blockhash(block.number-1), seed ))%100);
}
/* generates a number from 0 to 2^n based on the last n blocks */
function multiBlockRandomGen(uint seed, uint size) constant returns (uint randomNumber) {
uint n = 0;
for (uint i = 0; i < size; i++){
@bretton
bretton / improved-lnd-bitcoind-mainnet.md
Last active June 26, 2024 16:08
Detailed guide to installing LND and Bitcoind on Ubuntu 16.04 LTS for Mainnet

Intro

This guide is specific to getting LND 0.5-beta and Bitcoind running on Ubuntu 16.04 LTS for mainnet. It is aging rapidly and includes steps not necessary on newer versions of LND. As of April 2021 it is very out of date for bitcoind. As of December 2021 it is outdated for LND too.

Original installation guide:

This guide is broken into the following sections:

  • Install bitcoind and set to start automatically
  • Install development tools and dependancies
@amiller
amiller / TinyDuplex.sol
Last active May 13, 2019 20:38
TinyDuplex.sol: minimalist duplex micropayment channel for Ethereum
pragma solidity ^0.4.22;
// ECE 398 SC - Smart Contracts and Blockchain Security
// http://soc1024.ece.illinois.edu/teaching/ece398sc/spring2018/
// Simpest possible duplex-micropayment channel
// - Funded with an up front amount at initialization
// - The contract creator is called "alice". The other party, "bob", is passed
// as an argument to the Constructor
// - There is no fixed deadline, but instead any party can initiate a dispute,
// which lasts for a fixed time
@BjornvdLaan
BjornvdLaan / BLSExample.sol
Last active April 10, 2023 07:49
Verification of BLS signatures and BGLS aggregate signatures in Ethereum
pragma solidity ^0.4.14;
/*
Example of how to verify BLS signatures and BGLS aggregate signatures in Ethereum.
Signatures are generated using https://github.com/Project-Arda/bgls
Code is based on https://github.com/jstoxrocky/zksnarks_example
*/
contract BLSExample {