gavinandresen

O(1) Block Propagation

The problem

Bitcoin miners want their newly-found blocks to propagate across the network as quickly as possible, because every millisecond of delay increases the chances that another block, found at about the same time, wins the "block race."

slothbag

2014-Mar-06 22:34:00 WRN Launching child 1
Loading: "/usr/src/rippled/build/rippled.cfg"
terminate called after throwing an instance of 'beast::BadLexicalCast'
  what():  std::bad_cast

karlgluck

What's this all about?

Digital cryptography! This is a subject I've been interested in since taking a class with Prof. Fred Schneider back in college. Articles pop up on Hacker News fairly often that pique my interest and this technique is the result of one of them.

Specifically, this is about Lamport signatures. There are many signature algorithms (ECDSA and RSA are the most commonly used) but Lamport signatures are unique because they are formed using a hash function. Many cryptographers believe that this makes them resistant to attacks made possible by quantum computers.

How does a Lamport Signature work?

piscisaureus

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = [email protected]:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

sipa

Beyond IP Transactions: towards a payment protocol
==================================================

IP transactions were originally introduced as a first "out-of-band" protocol
for negotiating a transaction output's public key. Being inconvenient and
insecure, they became obsolete, and recent versions of bitcoin don't support
them anymore.

The result is that static bitcoin addresses have become the most common way of
defining requested payments. This may be fine for anonymous donations, but is not