Daniel Himmelstein dhimmel

Chat GPT "DAN" (and other "Jailbreaks")

Git pre-push hook

It will check if current branch is master, then ask a confirmation, in case of master branch

install

install a recent version of git (https://git-scm.com/download/mac) eg:

$ brew install git

If you are on a Mac, substitute command for control. Don't type the + (it means press both keys at once).

Shortcuts when in either command mode (outside the cells) or edit mode (inside a cell):

Shift + Enter run selected cell or cells - if no cells below, insert a code cell below
Ctrl + B toggle hide/show left sidebar
Ctrl + S save and checkpoint
Ctrl + Shift + S save as

Bitcoin Gold (BTG) was 51% attacked

Preamble

Bitcoin Gold is a Bitcoin hard-fork that aims to be GPU-mineable by using the Equihash algorithm with parameters (144, 5) also known as "Zhash". The Bitcoin Gold website claims Zhash "uses more memory than an ASIC can muster, but runs fine on many graphics cards". Bitcoin Gold was previously 51% attacked in May 2018 when it was estimated that up to $18 million worth of BTG was double-spent.

The Attacks

Between Thursday and Friday we detected two deep reorgs on BTG, both of which contained double-spends. Their details are listed below. All times are GMT.

	prefixes: \|
	PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
	PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
	PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
	PREFIX dct: <http://purl.org/dc/terms/>
	PREFIX owl: <http://www.w3.org/2002/07/owl#>
	PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
	PREFIX meshv: <http://id.nlm.nih.gov/mesh/vocab#>
	PREFIX mesh: <http://id.nlm.nih.gov/mesh/>
	PREFIX meshsv: <http://id.nlm.nih.gov/mesh/skos/>

	Reorg 0 at 2020-01-23T18:01:32 db ID: 85779
	Depth 14
	Length 13
	Est attacker chain duration 2:13:28
	Est attacker hashrate 2.53 MH/s
	Nicehash hashrate 3.41 MH/s
	Nicehash price 0.86 BTC/MH/s/Day
	Est Nicehash cost 0.2013653 BTC

	Reorg Blocks

	#!/usr/bin/env python
	'''
	if you find this script helpful and would like to give some crypto to
	the cause, we would be very happy to receive it :)
	donate bitcoin / counterparty: 3L19gTtMMJHpkAjYVduUZETdduwAfM7NGR
	'''
	import sys
	import json
	import requests
	from requests.auth import HTTPBasicAuth

	#
	# Apple SuperDrive initialization rule
	#
	# See: https://gist.github.com/yookoala/818c1ff057e3d965980b7fd3bf8f77a6

	ACTION=="add", ATTRS{idProduct}=="1500", ATTRS{idVendor}=="05ac", DRIVERS=="usb", RUN+="/usr/bin/sg_raw --cmdset=1 %r/sr%n EA 00 00 00 00 00 01"