MENU

Sydney Bitcoin ATM Machine

October 21, 2016
0
5274
0
On my recent trip to Sydney, I went back to visit the only bitcoin ATM machine that allows you to withdraw cash. Unfortunately it has been removed. I was there in August 2015 and documented the interesting process. Bitcoin ATM machines are not that scary I’ve contacted Patrick from Abatech but with no success. They have recently updated their website (http://abatech.com.au) promoting their mobile wallet instead of their ATM machines. They did have 1 in Melbourne and Brisbane but who knows if they are operational as well. It was the right step in the right direction but maybe it wasn’t making as much money for the owners. It is probably ahead of its time as well.
Read More ›

The Creature from Jekyll Island : A Second Look at the Federal Reserve

October 15, 2016
0
5316
0
The study of crypto-currencies and blockchain technologies has led me on a path that I would have never travelled on otherwise. Never in a million years would I have thought to read this book. The Creature from Jekyll Island is about how the Federal Reserve was created. It talks about where does money come from? Where does it go? Who makes it? The book is pretty chunky and I must admit, from about half way to 3/4 it got a bit heavy but the first half and the last quarter are brilliant. They say that to predict the future, one must study the past. From reading this book, I am not surprised that we are in the financial mess that we are in today. What is more alarming is that I don’t think it was even preventable. In fact, it was inevitable! Crypto-currencies with it’s fixed supply won’t solve all the problems, but it’s a start. Just the mere concept of being able to create a trillion dollars out of nothing blows my mind knowing what I know now.
Read More ›

Wellington October Blockchain Meetup

October 11, 2016
0
5516
0
Another interesting evening at the Wellington Bitcoin/Blockchain meetup. I presented on “How transactions are secured on the blockchain”, got some audience participation and gave a live demo as well. We took a closer look at the genesis block from the bitcoin blockchain and looked at the components of a single block. We highlighted the point that to understand how a blockchain works, it’s valuable to understand what’s in a single block. We went through some hands on Proof of Work examples where I dusted off my origami skills and made some candidate blocks. We had a race to see who could roll a 3 or lower. The winner then got their version of the block secured on the blockchain. There were some really good discussions afterwards on China’s involvement, on bitcoin scaling, on how blocks were constructed and if someone could create their own block if it followed all the right specifications. Many of the audience members contributed their knowledge and point of view also. Here is a pdf to the presentation. securing-the-blockchain-key Thanks to Sebastian and Wyn from API Talent for their hospitality.
Read More ›

Building Blockchain Momentum in Wellington, New Zealand

October 3, 2016
0
4685
0
The last few months has seen an increased in activity in Wellington around blockchains and smart contract. September 3 2016 – Lets Talk Ethereum September 7 2016 – What’s happening with Bitcoin/Blockchain in Wgtn September 28 2016 – Ethereum: Smart Contract Basics What’s coming up: October 10 2016 – Guest international speaker – Arthur Falls from ConsenSys Systems October 11 2016 – Live demo on “How transactions are secured on the Blockchain” Currently there is an Wellington Ethereum NZ meetup and a Wellington bitcoin/blockchain meet up. We are in the process of combining the 2 communities and keeping the momentum going, so stay tuned!
Read More ›

Neat paper on Blockchains, Smart Contracts and IoT

October 2, 2016
0
4571
0
Here is a link to a neat paper called Blockchains and Smart Contracts for the Internet of Things by Konstantinos Christidis, (Graduate Student Member, IEEE) and Michael Devetsikiotis, (Fellow, IEEE). http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7467408 It does a great job explaining some of the basics of blockchains and smart contracts before getting into lots of possible applications. If the above link is broken, here is another link: blockchains-and-smart-contracts-for-the-iot
Read More ›

How to build bfgminer for the Alchemy miner from scratch

September 30, 2016
0
4443
0
Sometimes when everything has gone wrong and nothing is working, the last resort is to build the software from scratch. It actually isn’t as hard as it sounds. Here are the steps for a raspberry pi: Grab the latest raspberry pi image by downloading the image and placing it on an 8Gb usb card. Connect the raspberry pi to your computer via USB to TTL Serial Cable or with an ethernet cable. Run these commands >> sudo apt-get install >> sudo apt-get install build-essential autoconf automake libtool pkg-config libcurl4-gnutls-dev libjansson-dev uthash-dev libncurses5-dev libudev-dev libusb-1.0-0-dev libevent-dev >> mkdir bfgminer >> sudo git clone --branch alcheminer_USB-Dongle_Support https://github.com/jstefanop/bfgminer.git >> cd bfgminer >> ./autogen.sh >> sudo chmod +x ./configure >> ./configure CFLAGS=-O3 --enable-scrypt --enable-alchemist --disable-other-drivers --enable-broad-udevrules >> sudo make >> sudo make install It should take about 30-60 minutes depending on if you have a fresh pi image already at hand or you need to create it and the speed of your internet. Reference: https://bitcointalk.org/index.php?topic=1468120.0
Read More ›

Wellington Ethereum Meetup: Smart Contract Basics

September 28, 2016
0
3705
0
Great to see momentum continuing at the Wellington Ethereum meetup yesterday. It was great to see a smart contract in action with Felix provided a short demo of a birthday contract in Ethereum. Thanks to Mark and 3months for hosting. Discussions included how the birthday smart contract worked, a plugin that provided Ethereum features and functions to the chrome browser called Metamask and that the DevCon2 videos should be coming out soon. The slides for DevCon2 day one are out and can be seen here: #PowerPoint Slides from #ethereum #DevCon2 by Misha Yang https://t.co/U2uXhr79Cp — Sean (@seandotau) September 28, 2016 Discussions also centered around how to get hold of bitcoins and one person talked about accepting bitcoins and saving up to 7% of transaction cost for his laser cut golden mean caliper business. (I had to google that too!) The next blockchain meet up is in 2 weeks time. Live demo on “How transactions are secured on the Blockchain” Tuesday, Oct 11, 2016, 5:45 PM API TalentLevel 1, 166 Featherston Street Wellington, NZ 20 Members Went Howdy all!To continue the momentum, join us for a live demo showing how transactions are secured on the blockchain. This will give everyone a chance to see how things work instead […]
Read More ›

IBM Blockchain for developers

September 15, 2016
0
4671
0
Introduction I had heard about IBM donating 44k lines of code to the Hyperledger project a while ago and was curious interested to see what IBM had to offer in the blockchain space. IBM has a neat little learning path to understand more about blockchain technologies. It’s a free self paced course that takes a few hours (not really the 6 that it says) and does a pretty good job at explaining IBM, blockchain and the Hyperledger. What was good The course was professionally done with goals, quizzes at the end of each course, videos and notes and the best part was the hands on development environment Bluemix. It’s only a 30 day trial but no credit card was required. The content was good where IBM introduced terminology such as “world state” to mean the state of the blockchain or the ledger and “blockchain fabric” to mean blockchain framework. Above is a neat diagram of the various blockchain components in the IBM Hyperledger stack. The above screenshot shows the 1 click blockchain deployment process within Bluemix where everything is set up automatically. The car leasing demo was interesting behind the scenes but the front end interface was just like any […]
Read More ›

Rich Dad’s Conspiracy of the Rich and Cryptocurrencies

September 12, 2016
0
4891
0
What is the link between this book and digital currencies or cryptocurrencies or even blockchain technologies? Surprisingly, the first part of the book goes into the history of where money came from, how in 1971, the USD was severed from the gold standard and from then on the US and other countries started printing money. Printing money is regarded as a bad thing for many reasons. This is why when bitcoin was created, it has a fixed supply of around 21 million. It was designed to mimic that of a natural resource like good. Finite. Everyone nowadays is jumping on this band wagon of blockchain technologies and smart contracts, which is great. I am as well. The difference being that my apprenticeship has started at the bottom. Learning about bitcoin has forced me to learn about what money is, where it came from and hopefully where it is going. Bitcoin wasn’t invented just for fun. It wasn’t invented so we could have smart contracts to automatically contracts without the need for lawyers. It was invented because there is a fundamental problem with the worlds money supply. There is an imbalance which means there will be a shift if something is […]
Read More ›

Wellington September Bitcoin/Blockchain Meetup

September 8, 2016
0
3850
0
I co-organised the Wellington bitcoin/blockchain meet up yesterday and it was great to see a bunch of dedicated people turn up. We discussed topics from blockchain technologies, to Ethereum smart contracts to bitcoin trading. We also shared the mandatory rabbit hold story of how we all got into this “thing”. Thanks to Sebastian from API Talent for hosting us. Sebastian is the organiser of the Wellington AWS Users group. I am currently planning the next bitcoin/blockchain meetup so stay tuned!
Read More ›

Learning how to secure the blockchain

September 4, 2016
0
4032
0
It has been a very busy few weeks since my first trip to the US. As part of my STEM contribution, I was looking for old mining boards to first learn how mining works and then to share this knowledge with the younger generation. I put a shout on the community forums a while ago and a very generous person offered one of his boards. It would have cost a lot to send it to NZ so I ended up picking it up while in the US. From attending various meet ups and talking with all sorts of people, everyone wants “in” on blockchain applications and smart contracts. That is because it’s the buzz at the moment. The good old bitcoin cryptocurrency has been left in the dust. There is also the negative connotation that surrounds bitcoins such as “it’s used for buying drugs” and “it’s a speculative currency”. Whilst these maybe true, understanding components of how bitcoin works provides an excellent foundation to build upon. One example is analysing what is inside a blockchain. Another example is that of securing the blockchain, aka mining. Currently the main algorithm used to secure transactions on the blockchain is Proof of Work. It has […]
Read More ›

Visiting Coinbase in San Francisco

August 16, 2016
0
4805
0
    I had the privilege visiting the Coinbase Headquarters in San Francisco as I was interested in a position there. Coinbase is one of the largest digital currency exchanges in the world and certainly well funded. I had an initial phone screening conversation with Brittany, the HR person there. Then I talked to another HR person, Alvin. I then had a phone interview with John. I was then invited to come onsite for 2 face to face technical interviews. Gotta say, the process was thorough! Their office was nice with amazing views in downtown San Francisco. The first technical interview was with Brad who was a nice and knowledgable guy. I was given a problem of trying to balance the spend of a group of people where one person paid for the rest of the group or sub group. After an hour I then moved to another room and talked with Craig, a software engineer where I had a warm up question. It was to find the angle between the long hand and the short hand of an analogue clock at the time of 3:15. Next, I had to code up a function to perform the Fibonacci sequence using https://codepair.hackerrank.com It […]
Read More ›

Nakamoto: San Francisco’s First Bitcoin Store

August 11, 2016
0
3734
0
My curiosity for knowledge led me to visit a store in San Francisco called Nakamotos. It wasn’t hard to find but I walked right past it the first time. I was expecting but the actual shop front was like:       It was pretty quite on the day I was there. Inside were 2 ATMs, some books and lots of other souvenirs. Managed to leave with a souvenir for myself. I walked from San Francisco CalTrain station partly to explore the city. It took ages. I would highly recommend Ubering it.  
Read More ›

Going POW on the Blockchain

July 27, 2016
2
4646
0
When I first came across PoW, thoughts of the dynamic duo batman and robin came to mind. Then “Prisoner of War”. Maybe Proof of Weapons (of Mass Destruction)? It actually stands for Proof of Work and to understand it, let’s take a step back. Miners process transactions on the blockchain. What this really means is that miners collect all the transactions into a block and then validate and verify the information based on preset rules. Once all the rules are satisfied, miners then proposes that their particular collection of transactions should be accepted as the next block on the blockchain. Thousands of miners around the world do this, so whose block should be accepted? This is where Proof of Work comes in. All the miners need to “prove they did some work”. They don’t have to prove they did the most work or the best quality work, just that some work was done. Proof of Work is designed to be computationally hard to perform but easy to validate and also random in nature. There are lots of in-depth articles on the inner workings of PoW but let’s draw an analogy. Imagine having 2 dice. The chances of obtain a total of […]
Read More ›

Ethereum update their crowdsale tutorial page

July 21, 2016
0
4723
0
I was surprised at why the sample code was set as regular text. Seems likes the guys at Ethereum may have missed an opening bracket or something. It was good though to see Ethereum update their crowdsale tutorial page at https://www.ethereum.org/crowdsale. I’m sure others would have noticed this as well!
Read More ›

Digital signatures and the blockchain

July 14, 2016
2
25475
0
Introduction Understanding how digital signatures work is fundamental to understanding how blockchain technologies work. Let’s first draw a comparison to paying a restaurant bill with a credit card. Paying a bill at a restaurant Think of what happened the last time you paid your bill at the restaurant with your credit card. Here is a snapshot: You pull the card from your wallet and you might have a photo ID on the card. This proves you own* the card. You sign the bill in front of the waiter. The proves you are the “rightful” owner of the card. You check the receipt against the bill. You prove that the amount charged hasn’t been altered somewhere in the process. * It actually proves possession of the card but the entire process serves to illustrate a simplistic view and is not without it’s flaws. These 3 points illustrate 3 key properties: Ownership. The card belongs to you. Transaction authentication and non-repudiation. The waiter can verify that the owner signed the bill and the owner cannot deny the signing. Data Integrity. The amount charged was accurate. How can this be performed in a digital world where both parties hide behind a screen, do not know […]
Read More ›

Bitcoin nodes around the world

July 12, 2016
0
3752
0
https://bitnodes.21.co is a very interesting site that shows all the bitcoin nodes around the world in real time. Bitcoin nodes are individuals and companies that support the bitcoin peer to peer network.
Read More ›

Transaction fee for mobile bitcoin wallets

July 9, 2016
0
3710
0
Transaction fees of mobile bitcoin wallets can vary with some set by the user and some set and controlled by the wallet provider.
Read More ›

Who’s Securing the Blockchain?

June 30, 2016
0
3536
0
Back in the days when blockchain mining started, anyone could mine with their regular home computer. Unfortunately this was as decentralised as it got. Mining remember, is the process of confirming transactions and creating a block on the blockchain. It is a fundamental component of the blockchain technology. No mining, no blockchain. As the story goes, mining technology has evolved at an incredible speeds. From using home computers, known as CPU mining, to using dedicated gaming graphics card,  (GPU mining), to using programming chips (FPGA’s) and now Application Specific Integrated Chips, ASIC’s. ASIC’s have evolved from 55 nanometer silicon wafers to 28 nm and now, to the release of 14nm chips. The lower the number, the more chips on the silicon, the more processing power to be had. To understand who is mining to secure the blockchain, let’s go to the top of the food chain. The chip foundries. These are the guys that actually make the chips and there are only a handful of foundries around the world such as Global Foundries (GF), Taiwan Semiconductor Manufacturing Company (TSMC) and Semiconductor Manufacturing International Corporation (SMIC). An enormous amount of investment is required to fabricate mining chips To get in the […]
Read More ›

How to send ethers in Mist

June 27, 2016
0
4403
0
With your Mist wallet installed and synchronised to the test network, let’s send some test ether to a friend. This should take less than 5 minutes.
Read More ›