MENU

ISO/TC307 Blockchains and New Zealand

April 6, 2018
0
6102
0
I had the opportunity to give a brief presentation on Blockchains and the NZ landscape to the Standards Approval Board (https://www.standards.govt.nz/about-us/approval-board/) as part of Standards NZ proposal for NZ to move from an observer membership (O) status to participation (P) status for “ISO/TC 307 Blockchain and distributed ledger technologies”. Steve Lowe from Standards NZ is leading the charge where the standards covers the following scope: ISO/TC 307/SG 1 Reference architecture, taxonomy and ontology ISO/TC 307/SG 2 Use cases ISO/TC 307/SG 3 Security and privacy ISO/TC 307/SG 4 Identity ISO/TC 307/SG 5 Smart contracts ISO/TC 307/SG 6 Governance of blockchain and distributed ledger technology systems ISO/TC 307/SG 7 Interoperability of blockchain and distributed ledger technology systems ISO/TC 307/WG 1 Foundations ISO/TC 307/WG 2 Security, privacy and identity ISO/TC 307/WG 3 Smart contracts and their applications SG: Study Group, WG: Working Group. Participation status means NZ will have a voice and a vote to help contribute to the future direction of blockchain technologies. Currently there are 32 participating members and 14 observing members. ISO/TC 307 has met twice, most recently in Tokyo. Work is progressing in many areas including reference architecture, terminology, smart contracts, and security and identity. Separate study groups were established […]
Read More ›

Cryptocurrencies and Tax in NZ

April 3, 2018
0
4874
0
This is how to official handle cryptocurrencies and tax in New Zealand. https://media.ird.govt.nz/articles/cryptocurrency-investors-reminded-of-their-tax-obligations/
Read More ›

Great resources for learning about NEO

March 9, 2018
0
5366
0
Here are some great links to learn about NEO. The analogies are very good. https://steemit.com/cryptocurrency/@basiccrypto/almost-everything-you-wanted-to-know-about-neo-part-1-of-2 https://steemit.com/cryptocurrency/@basiccrypto/almost-everything-you-wanted-to-know-about-neo-part-2-of-2 https://steemit.com/neo/@basiccrypto/neo-s-consensus-protocol-how-delegated-byzantine-fault-tolerance-works
Read More ›

Raspberry Pi 3, Node and Ethereum

March 6, 2018
0
9889
0
Ever wanted to receive payment with a cryptocurrency and then enable an action such as open a door or turn on a light? Here is a quick overview of how this can be done with Ethereum, a Raspberry Pi and Nodejs. Summary The idea is to display a QR code on a tablet where payments can be made with crypto and upon receipt of payment an LED is turned on. The webpage is running on a Raspberry Pi which is also running geth which is the Ethereum blockchain client. The neat thing is that there is an experimental “light” sync mode that only obtains the current blockchain state and only requires ~400Mb of disk space. See it in action In the video above I use Metamask to make the test ether payment. It takes about 30 seconds for the transaction to be acknowledge and the LED to light up. Html Payment Page The payment page basically consists of a QR code for the user to make a crypto payment and in the background, it connects to the local Ethereum blockchain to get the current balance and to listen for the next block to arrive. When it does, it queries the […]
Read More ›

How to run Ethereum on a Raspberry Pi 2

March 2, 2018
1
8799
0
Interested in getting Ethereum running on a Raspberry Pi 2? Here are some simple steps: Step 1: You get, I get, We get >> wget https://gethstore.blob.core.windows.net/builds/geth-linux-arm7-1.8.1-1e67410e.tar.gz Of course this means you know what wget is (a way to download files using cmd) and you have already ssh’d into your raspberry pi with something like ssh pi@192.168.x.x Where did this link come from? It came from https://geth.ethereum.org/downloads/ Search for Linux -> armv7 for the Raspberry Pi 2 and you’ll find the link. This is important to know because you’ll want to change the link to retrieve the latest binary. Step 2: Lay down the tar-seal and zip it up >> tar -xvf geth-linux-arm7-1.8.1-1e67410e.tar.gz The file downloaded is a tar or a “Tape Archive” in reference to the good old days when files would be put on “tapes” and then archived for storage. It is also known as a tarball. It stores multiple files together as a single file. gz  stands for GNU zip which compresses it. This is the equivalent of Winzip in the windows world. The x flag extracts it, v stands for verbose output, telling the user what is happening in more details and f tells tar to use the file […]
Read More ›

CustomContracts is not defined at

February 20, 2018
0
8735
0
Trying to delete a contract in Mist and getting this error? VM659:1 Uncaught ReferenceError: CustomContracts is not defined at <anonymous>:1:1 There is a work around you’ll find useful. Right click in the Contracts window and click Open developers tools. It should have an autocomplete and you should be able to run CustomContracts.find().fetch(). Expand an object, grab the _id and run CustomContracts.remove(“put_id_here”)  
Read More ›

The Subtleties of Siacoin

February 16, 2018
0
5484
0
First of all, I’m a fan of Siacoin. The team appears upfront and transparent. They’ve had a working product for a long time now and the concept is good, monetising spare hard disk space. But it’s not until you go through the process that you really understand some of the subtleties of Siacoin. The main one being, it’s not really designed for the average Joe to rent a few Gb of disk space and make some money. It’s for the professionals and here is why. When I heard of monetising spare disk space, I quickly started hunting for the old spare hard drives I had lying around. A few 2.5 40Gb from old laptops 5 years ago, an 80Gb and a 160Gb. Great. I downloaded the client and then discovered I needed to buy Siacoin to make Siacoin. This is because wannabe hosters like myself need to put some Siacoins on the line because if I don’t keep my hard drives running, my customers (renters) will lose their files they store with me. This is called collateral and that’s fair. So I got set up with some Siacoins and managed to connect to the network and make 40Gb + 40Gb […]
Read More ›

Schnorr Signatures by Pieter Wuille

February 12, 2018
0
6544
0
Another neat video by Pieter explaining Schnorr Signatures Another useful reference link: http://diyhpl.us/~bryan/papers2/bitcoin/bitcoin-tech-dev-talks-schnorr-signatures.2018-02-01.pdf    
Read More ›

Connecting Geth to MetaMask and Mist

February 8, 2018
0
9307
1
If you have geth, the Go Ethereum client running and you want to connect Mist or MetaMask to you get a nice front end, here is how you do it. Start geth with: > geth --datadir ./chaindata init ./myGenesisFile.json Note: If you don’t have a genesis file, one is provided at the end. The run > geth --datadir ./chaindata --networkid 1994 to spin up the private Ethereum blockchain Mist The easiest way to connect Mist to this private blockchain is to start it via command line and passing in the location of the ipc file with the rpc flag. > ./Mist --rpc /Users/cloudnthings/privatechain/chaindata/geth.ipc You should get the word PRIVATE-NET at the top. Click Launch Application and you should be away. If you get this error: NCAUGHT EXCEPTION { Error: connect ENOENT Users/cloudnthings/privatechain/chaindata/geth.ipc Then it means you have your syntax wrong. The most common mistake is not having a double dash before rpc (- – rpc) MetaMask To connect to MetaMask, you need to start the private Ethereum blockchain with an extra rpc flag. > geth --datadir ./chaindata --networkid 1994 --rpc You can connect to the blockchain as per normal via geth attach like so: > geth attach http://127.0.0.1:8545 or in MetaMask, simple choose localhost […]
Read More ›

Talking Bitcoin on NewstalkZB

February 6, 2018
0
6393
0
It was a great experience going into the NewstalkZB studio and doing a brief radio interview with Heather Du Plessis-Allan on Bitcoin. http://www.newstalkzb.co.nz/on-air/wellington/wellington-mornings-with-heather-du-plessis-allan/audio/sean-au-bitcoin/ In case that link breaks, click below. Managed to garner a pic as well!  
Read More ›

Australian Blockchain Landscape Tour

February 2, 2018
0
5890
0
I landed in Sydney on the evening of Wednesday the 11th of October at 6pm and arrived at my apartment ready to chillax. I knew there was a Sydney Bitcoin meetup at the Metropolitan Hotel and was in two minds about attending. Being an introverted geek my first instinct was “Yeah, nah, I’ll go next time”. The uncomfortable feeling of walking into a room not knowing anyone and feeling awkward has been with me my whole life but on this occasion, I told myself to just get over it! What transpired set the scene for the entire trip. I met Adriana, one of the meetup founder stalwarts and started asking a million questions. Sitting next to her was a guy called Jack who lives about an hour out of Sydney but makes the trip in to all these meetups. I was then introduced to Jason, the man with the red hat. The other founder of the meetup and respected community member.   Adriana mentioned she was running a blockchain event at a co-working space called Fishburners as part of the Sydney Spark Festival Fintech event the following week. I ended up volunteering and had a blast.   I learnt about […]
Read More ›

What is Geth?

January 23, 2018
6
17048
0
Understanding how to download and interact with the Ethereum blockchain is a crucial part for anyone learning Ethereum. There are several popular clients to work with the Ethereum blockchain. They are: eth – a client written in C++ geth – a client written in Go pyethapp – a client written in python There’s also Haskell and Java. There is a more detailed description here. Here we will focus on Geth. What is Geth? Geth is a multipurpose command line tool that runs a full Ethereum node implemented in Go. It offers three interfaces: the command line subcommands and options, a Json-rpc server and an interactive console. Downloading Geth There are several ways to download Geth. One is to visit https://geth.ethereum.org/downloads/ and download the latest version suitable for your OS. Another option is to use brew for OSX users. Follow the instructions here. With brew, the steps are essentially: brew tap ethereum/ethereum brew install ethereum What this does is install the geth client at /usr/local/Cellar/ethereum/1.7.3/bin Then you can go to your terminal and run >> geth When you run this command, geth will start downloading the entire blockchain onto your laptop. The location of the chaindata will be shown in the terminal window. […]
Read More ›

Great Siacoin farming tutorial

January 18, 2018
0
5448
0
Here is a great resource from Sia Today (https://sia.today/) on how to get a computer up and running as a host to rent our excess storage on your hard drive. Unfortunately the article doesn’t have the date it was published but it seems like it was mid 2017. There are lots of screenshots, probably a bit too much but this is great for beginners.  
Read More ›

Smart contract workshop #2: Remix and MetaMask

January 14, 2018
0
8065
0
It was great to see the dedicated ones turned up yesterday on a beautiful Saturday morning to learn about MetaMask and Remix and deploy a hello world smart contract. We went through the following topics: Install MetaMask Get some test ether Mixing it up with Remix Hello World Compile and deploy captain! Interactive with your smart contract Understanding the code Bonus code It really was about downloading and installing MetaMask, getting some test ether, opening Remix and deploying 4 lines of code and seeing the contract on the Etherscan. It was great to see some new faces and hopefully the learning by doing is helping those who actually want to get a better understanding of what this technology can do. Next week we’ll be looking at MyEtherWallet (MEW) and also creating professional paper wallets on photographic paper with holographic stickers as souvenirs or gifts or just if you want something physical to tuck under your mattress. There will be a catch up meetup on Tuesday 5:30pm for the city folks. Details of that can be found at: https://www.meetup.com/smartcontracts/events/246629747/ If you missed the meetup but want to check out the topics, visit: https://blockchains.learndot.com/ and connect with us on Telegram: https://t.me/joinchat/G84KThDRZaXOJsxa7oQHmw Catch everyone next week.
Read More ›

Vitalik and Gavin on Craig

January 10, 2018
0
5921
0
I had the opportunity to ask Craig Wright a question last week about BitcoinCash. (He is obviously a BitcoinCash fan). He was also challenged to transfer some funds from block #1 but politely declined. There is a continuous debate on whether he is Satoshi or not and we may never know. He speaks very knowledgeably on subject and is obviously very smart. I can’t help to re-share the short video down below where Gavin shares why he thinks Craig is Satoshi and Vitalik gives a great reason why he isn’t based on signal theory. What gets me though is that if Craig is Satoshi, he would know both methods of proving he is Satoshi as described by Vitalik. The first method would leave no doubt in everyone’s mind. The second option is actually the more clever. It leaves doubt, but keeps him in the lime light. It also gives Satoshi this split personality. A messiah type figure in one realm and a very normal person in the other realm. I still not 100% sure and if I had to guess I would say that Craig is not Satoshi, but there is always more than meets the eye.
Read More ›

Hello World Ethereum Smart Contract

January 4, 2018
0
7654
1
Introduction There are lots of simple Ethereum Hello World tutorials around to cater for everyone’s level. This tutorial builds on a 2016 version by Karl Floersh and attempts to keep things very simple. All that is required to be installed is Meta Mask which is currently a Chrome only plugin and is essentially an Ethereum light client browser plugin. More formally: “MetaMask is a bridge that allows you to visit the distributed web of tomorrow in your browser today. It allows you to run Ethereum dApps right in your browser without running a full Ethereum node.“ Outcome To deploy a hello world smart contract on the Ethereum network. Here is the code. It’s 1 contract consisting of 1 function and 1 event. contract HelloWorld { event log_string(bytes32 log); // Event function () { // Fallback Function log_string("Hello World!"); } } This guide should only take about 10 minutes to follow. Step 1: Install MetaMask In Chrome, search for MetaMask and install it as a plugin. Then create an account and change the network to Ropsten. This is the test network. In order to get some test ether, click “BUY” and click “Ropsten test Faucet”. This will take you to https://faucet.metamask.io/ […]
Read More ›

Smart Contract Workshop #1 – Mist

December 30, 2017
0
6395
1
It was great to see bunch of dedicated people gather at 1st Assembly in Lower Hutt to learn Mist, an Ethereum browser and wallet. The tasks were: Downloading Mist Syncing Mist Saving space Mining test ether Creating new accounts Sending ether between accounts The main challenge was downloading the 8Gb Ropsten testnet blockchain. We had some USB’s to pass around with the testnet blockchain on it, but copying that amount of data took a bit of time. For those interested in the workshop content, you can see what we went through at https://blockchains.learndot.com. Register an account, go through the notes and exercises. The process of doing the task created lots of questions such as: What is the difference between Mist and Ethereum Wallet? How do I change networks? How do I know if it is mining test ether? Where do I put the chaindata file? and many more In the end most managed to sync Mist, mine some test ether and send them between accounts which was great to see. In the coming workshops we’ll be building a Hello World smart contract, learning about tokens and eventually building an EIP20 token. There is no pre-requisite knowledge required because we’ll all end […]
Read More ›

Ethereum Smart Contract Revamp

December 28, 2017
0
6479
1
I’ve been meaning to jump back into smart contracts for a while now and thought what better time than now with so many experts around me. Here is one of the most simplest contracts you can write in Remix, which is an amazing online Solidity IDE written by some Russian Einstein like kid. pragma solidity ^0.4.17; contract light { event TurnLightOn(string thing); function () public { TurnLightOn("We should turn the light on"); } } It should be self explanatory but just in case, all smart contracts need to start with the pragma first line otherwise you’ll get a compilation error. The contract is given a name called light, it generates an event and has a public fall back function. A fall back function is how The DAO hack happened. It is a default function that gets called when no function is specified. Officially “Fallback functions are triggered when the function signature does not match any of the available functions in a Solidity contract.” This was for the hackathon so don’t use this code for real. In remix click the details button and you’ll the commands to deploy the code. Now comes the tricky part! You can’t just copy and paste […]
Read More ›

Symlink Mist data directory to save 52Gb

December 25, 2017
0
6405
0
When you download Mist and try to sync the Ethereum blockchain, your Ethereum folder will be in the following location: Mac: ~/Library/Ethereum Linux: ~/.ethereum Windows: %APPDATA%/Ethereum To save space, you can put your chaindata folder in another location such as a removable USB drive. Above you can see my chaindata folder is actually a symbolic link. To create a symbolic link run this command: > ln -s /Volumes/myUSBdrive/Ethereum/chaindata ~/Library/Ethereum/chaindata What I’ve done is I’ve put my 39Gb chaindata folder on a thumb drive and I’m linking to it. The reason why it’s 8.43Gb is because I haven’t removed test net yet. Testnet is 8.24Gb. Once this is removed, even more space will be saved. The other option is to create a symbolic link to the entire Ethereum folder but this results in an error where Mist is looking for a geth.ipc file which is created upon startup but it can’t because of the symbolic link. This is the easiest and quickest way to have the data directory located in a non default location. This is different to bitcoin-qt where the location can be specified in the configuration file. Ref: https://ethereum.stackexchange.com/questions/3307/in-mist-browser-how-can-i-move-the-data-blockchain-to-another-drive-on-mac-osx    
Read More ›

How to figure out what Hyperledger is

December 21, 2017
0
5504
0
I had the opportunity to explorer the Hyperledger project in more detail and my first impression was: “It is an inter web mess of “stuff” that takes a bit of time to understand. “ It took me a few days to slowly build a picture of what Hyperledger is and my second impression is: “It’s actually pretty neat once you breakdown the various components and there is a lot of potential.” The biggest challenge at the beginning was understanding all the terminology involved. Fabric, Sawtooth, Iroha, Composer, Indy etc, then figuring out how they fit together. Hint: They don’t. The next step involved taking 1 technology and peeling back the layers and understanding the architecture and concepts. If you have a current understanding of blockchains or even bitcoins it helps a lot because you can draw parallels. So what is Hyperledger? Some define Hyperledger by defining what it is not. This is helpful. It is not a company, not a cryptocurrency and not a blockchain. The definition that made sense straight away to me was: “Hyperledger is an umbrella project of open source blockchains and related tools” From here, let’s look at the components and rename them slightly. Platform Fabric: […]
Read More ›