t4sk

gen_tcp and GenServer example in Elixir (1.5.2)

Usage

server.ex

Server.start

t4sk

How to convert private key to WIF

0. Overview

WIF = base58check encode ([version byte][private key][checksum])

version byte = 80 for mainnet, ef for testnet and regtest

checksum = first 4 bytes of double SHA256 of private key

t4sk

How to compute OP_HASH160 of public key

OP_HASH160 of public key = RIPEMD160(SHA256(ECDSA_publicKey))

1. Generate address

> getnewaddress
mpLwhoaRWxfgdQAz8JnnH7NUuhS157DM61

2. Get public key

t4sk

How to get Public Key of a Bitcoin Address

Generate bitcoin address

> getnewaddress
mkAhnkryoSs3dLWeBhbhJsw5d1LMs3B3Lt

Get public key

> validateaddress mkAhnkryoSs3dLWeBhbhJsw5d1LMs3B3Lt

t4sk

How to create bitcoin address

0. Overview

Address = base58 encode ([version byte][public key hash][checksum])

version byte = 00 (for P2PKH on mainnet)

public key hash = RIPEMD160(SHA256(public key))

t4sk

How to create scriptPubKey for P2PKH

1. Get public key hash

Get the public key hash by computing OP_HASH160 of public key

In this example:

• public key: 033e8c5dcb8e35670de496b57c1fa4366800ce3be5fded9b8800759881bc8da2e5
• public key hash: 60d47ac02b129c08f94232ea506d1826424fe7be

t4sk

const Web3 = require("web3");
const assert = require("assert");

const web3 = new Web3();

const email = "email@email.com";
const COLORS = [
    "red",
    "blue",
    "yellow",

t4sk

Keybase proof

I hereby claim:

• I am t4sk on github.
• I am tsknk (https://keybase.io/tsknk) on keybase.
• I have a public key ASDyZ1hblodO_TVvXYnHmPsWLpqRbYlgG6xzpy0Br_8m7Qo

To claim this, I am signing this object:

t4sk

How to activate segwit on regtest

Start bitcoind

> bitcoind -regtest -daemon

Generate block chain

> bitcoin-cli -regtest generate 432

t4sk

pragma solidity ^0.5.3;

contract Wei {
    uint public oneEther = 1 ether;

    function test() public pure {
        assert(1 ether == 1e18 wei);
        assert(1 wei == 1);
    }
}