A description of known problems in Satoshi Nakamoto's paper, "Bitcoin: A Peer-to-Peer Electronic Cash System", as well as notes on terminology changes and how Bitcoin's implementation differs from that described in the paper.
The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power.
| # Add this snippet to the top of your playbook. | |
| # It will install python2 if missing (but checks first so no expensive repeated apt updates) | |
| # [email protected] | |
| - hosts: all | |
| gather_facts: False | |
| tasks: | |
| - name: install python 2 | |
| raw: test -e /usr/bin/python || (apt -y update && apt install -y python-minimal) |
Hi, I'm Lorna and I don't use a mouse. I have had RSI issues since a bad workstation setup at work in 2006. I've tried a number of extra hardware modifications but what works best for me is to use the keyboard and only the keyboard, so I'm in a good position and never reaching for anything else (except my coffee cup!). I rather unwisely took a job which required me to use a mac (I've been a linux user until now and also had the ability to choose my tools carefully) so here is my cheatsheet of the apps, tricks and keyboard shortcuts I'm using, mostly for my own reference. Since keyboard-only use is also great for productivity, you may also find some of these ideas useful, in which case at least something good has come of this :)
There's more detail on a few of these apps but here is a quick overview of the tools I've installed and found helpful
| Tool | Link | Comments |
|---|
| # Based on http://fearby.com/article/update-openssl-on-a-digital-ocean-vm/ | |
| $ sudo apt-get update | |
| $ sudo apt-get dist-upgrade | |
| $ wget ftp://ftp.openssl.org/source/openssl-1.0.2h.tar.gz | |
| $ tar -xvzf openssl-1.0.2h.tar.gz | |
| $ cd openssl-1.0.2h | |
| $ ./config --prefix=/usr/ | |
| $ make depend |
This is a basic collection of things I do when setting up a new headless ubuntu machine as a webserver. Following the steps below should give you a reasonable secure server with HTTP/2 support (including ALPN in chrome) and the fast NGINX server. I am happy to add things so leave a comment.
After creating the server (droplet on DigitalOcean) log in with
| #!/bin/bash | |
| head -n100 /dev/urandom | strings | egrep -o '([a-zA-Z0-9#%&^])' | awk '{ORS=""; print $1}' | head -c 35; echo |
| Latency Comparison Numbers | |
| -------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
Around 2006-2007, it was a bit of a fashion to hook lava lamps up to the build server. Normally, the green lava lamp would be on, but if the build failed, it would turn off and the red lava lamp would turn on.
By coincidence, I've actually met, about that time, (probably) the first person to hook up a lava lamp to a build server. It was Alberto Savoia, who'd founded a testing tools company (that did some very interesting things around generative testing that have basically never been noticed). Alberto had noticed that people did not react with any urgency when the build broke. They'd check in broken code and go off to something else, only reacting to the breakage they'd caused when some other programmer pulled the change and had problems.
Today, there is no reliable way to persist metadata for digital media as it travels across the internet.
Mine is working to build a global content registry on top of the Bitcoin blockchain to serve as an open metadata layer for canonical representations of digital media.
The goal of such a registry is to enable a new decentralized hypermedia protocol that powers the next generation of digital content applications, where creators and consumers to own their media, identity and interactions across the internet, without dependency on industrial or platform gatekeepers.
In March, we published a high level summary of how such such a system could work, titled the Canonical Content Registry. Today, we are taking the first steps to start building it by sharing a proposal for a technical implementation on top of Blockstore. We welcome your feedback and look forward to starting a conversation.
| <a href="https://github.com/lyoshenka" class="github-corner"> | |
| <svg width="80" height="80" viewBox="0 0 250 250" style="fill:#eee; color:#151513; position: absolute; top: 0; border: 0; right: 0;"> | |
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| <path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 15 |
