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What does semantic versioning have to do with Solidity

December 17, 2018
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Considering that the very first line of a solidity smart contract is something like: pragma solidity ^0.4.21 What does the caret really mean? The short answer is the caret or top hat (^) means the code will be compatible with compiler version from 0.4.21 to 0.5.0. This sounds easy to understand but it doesn’t actually tell the whole story. To really understand it, means learning about the concept of Semantic Versioning. In short, software versioning generally follows the format major.minor.revision. The caret is only one symbol out of various others such as ~ (tilde), * (wild card), || (logical or) and a bunch of typical ones such as >, >=, < and <=. The real definition of ^ is: “Allows changes that do not modify the left-most non-zero digit in the major.minor.version tuple format.“  This definition explains the following examples: ^1.2.3:  >=1.2.3 and <2.0.0 ^0.2.3: >=0.2.3 and <0.3.0 ^0.0.3: >=0.0.3 and <0.0.4 Tilde is interesting. The definition is: “Allows patch-level changes if a minor version is specified on the comparator. Allows minor-level changes if not.” which again is explained by these examples: ~1.2.3:  >=1.2.3 and <1.3.0 ~0.2.3: >=0.2.3 and <0.3.0 ~1.2:>=1.2.0 and <1.3.0 (Same as 1.2.x) ~1: >=1.0.0 <2.0.0 (Same as […]
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Checklist for developing smart contracts

December 15, 2018
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To start developing smart contracts in solidity, here is a check list of applications that will make your life easy. Note: Instructions here are geared towards Mac operating system. Remix Remix is an online Integrated Development Environment (IDE) where solidity smart contracts can be written. It can then be compiled and tested locally or combined with Metamask and deployed on testnet for instance. Editors – Atom or Sublime Atom or Sublime are popular editors. Atom is open source (ie free) while Sublime costs $80USD. While solidity smart contracts are written in remix, editors are useful to handle json, javascript and regular text files. Metamask Metamask is a browser extension that allows smart contracts to connect to various blockchains. It can be thought of as a bridge connecting the two together. Geth Geth or Go Ethereum is an Ethereum client which when run, acts as a node to connect to the Ethereum blockchain. It can be configured to point to mainnet, testnet or even set up in private mode. The following command will tell you if you have geth installed or not. > geth version Geth Version: 1.8.14-stable Architecture: amd64 Protocol Versions: [63 62] Network Id: 1 Go Version: go1.10.3 Operating […]
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Blockchain Training with Union Bank in Manila

December 5, 2018
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I had another opportunity to deliver a 5 day blockchain Ethereum developers course to Union Bank in Manila. Union Bank have been exploring blockchain technologies for a while and have several projects on the go. They created a blockchain institute which is part of their CSR program and invited students to apply. They had hundreds of applicants and filtered them down to 100. ConsenSys Academy was then invited to train the students. The students already had 9 days of training from NEM prior to us and will also have Hyperledger and Corda training in the New Year as well. Day 0 I had the option of arrive at either 5:30pm or 10:30pm and luckily choose the earlier option even though it was more expensive. This was because the flight eventually touched down at 7pm and it took 30 minutes to get my luggage and figure out how to order a Grab taxi. Even getting to the Grab taxi took a while coz when the taxi arrived in the “no pick up zone”, it was shuffled off and I had to figure out where it went to and how to get their. The ride took 90 minutes to cover ~15km due […]
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Blockchain training with LG in Korea

November 9, 2018
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Even as the crypto market continues to tank, the technology that underpins it is still going strong. Lots of very smart people are working very hard behind the scenes and lots more want to learn about blockchains. I had the chance to help train LG CNS (Consulting and Solutions, one of the business units) who were particularly interested in Quorum which is used for creating permissioned blockchains. From our hotel room we could see the many buildings of LG CNS. Security was very tight. Not surprising as it was around their R&D facility. We had to go through airport style x-ray scanners when leaving the building every day and have our laptops checked to make sure the serial number matched the one we registered with them.   The biggest challenge was actually the fact that we had a Korean interpreter for the entire 5 days. We had to speak slowly, clearly and pause after a few sentences to let the interpreter do her thing. It certainly did make things interesting! I teamed up with Carlos, who is the Global lead of Enterprise Education at ConsenSys Academy and has amazing knowledge of blockchains and is a world class trainer. Day one […]
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Chilling out with Tyler from Viant

November 2, 2018
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After our presentation at Proctor and Gamble, where Tyler, the co-founder of Viant (a blockchain-based platform for modeling business processes, tracking assets and building the supply chains of the future), demonstrated the platform with a hands on demo, we took the opportunity to have lunch at the local markets. The food available was amazing, especially the Hainan Chicken but we did sample a whole range of dishes. Viant is a very neat solution and is making great progress in the blockchain supply chain space. Keep an eye out for more announcements at https://viant.io/
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Blockchain 101 for Proctor & Gamble Singapore

October 26, 2018
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I had the opportunity to present a blockchain 101 to Proctor and Gamble in Singapore recently trying to engage an audience for an hour talking about ConsenSys, consensus and all things blockchains included concepts such as blockchains v distributed ledgers, cryptocurrencies v tokens, and of course use cases. Proctor and Gamble have launched a digital transformation program to learn more about disruptive technologies of which blockchains is one of them. The whole week was part of their ONWARD program where staff could attend all sorts of training in the area of their interest.   After I finished, Tyler Mulihive, the co-founder of Viant talked about their blockchain-based platform for modelling business processes, tracking assets and building the supply chains of the future. The attendees also managed to create an example supply chain application for themselves which was really neat.   Tyler, Michael Teo, (P&G Senior IT Manager for IT Innovations) and I. I also managed to have lunch with some of the awesome Singapore ConsenSys crew at WeWork at Suntec city. The office is a very nice space.  
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CareChain NZ: Blockchain in Healthcare Symposium

October 14, 2018
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I had to the opportunity to contribute to CareChain NZ: Blockchain in Healthcare Symposium in Auckland recently that was brilliantly organised by Tom Varghese and Tech Futures Lab. Mark from Blockchain Labs NZ kicked the evening off with a Blockchain 101 talking about what is distributed ledger technology, how does it work, and how can blockchain help healthcare. Mark had a great example of explaining trust and decentralisation using neighbourhood trading using trusty “Harold” (love the name!) who Alice and Bob have known for a long time as an example. Blockchain enables Harold to be removed from the equation. Next was Shahid Saiyad from IBM talking about what applications blockchains have the most promise in healthcare. IBM have put significant efforts in the blockchain space. The funniest talk of the evening had to go to Jerome Faury from Centrality. He kinda set the scene from the beginning with his t-shirt! Katherine Noall from Sphere Identity shared fascinating blockchain insights for identity management in healthcare. Kris Vette from Chain Ecosystem discussed the options to enable blockchain adoption and success in healthcare and what factors influence the scalability of blockchain projects. Alex Sims talked regulation and privacy (a topic she could talk […]
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Understanding The ICO Landscape Podcast with Jose Mota from OST

October 10, 2018
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I had the opportunity to share my knowledge on Tokenomics talking about tokens, ICOs and blockchains with podcaster Jose Mota. Check it out below. https://medium.com/ostdotcom/recap-from-ost-live-with-tokenomics-author-sean-au-understanding-the-ico-landscape-ed498d4700a0 https://itunes.apple.com/us/podcast/ost-live-blockchain-branded-tokens-and-token-economies/id1432951800?mt=2#episodeGuid=http%3A%2F%2Fwww.blubrry.com%2Fostlive%2F38114241%2F  
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How long does it take to do geth sync?

October 6, 2018
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Here are some latest stats on how long it takes to synchronise with the Ethereum blockchain. Geth can run in 3 modes. Fast, full or light. In light mode, geth gets only the current state. To verify elements, it needs to ask to full (archive) nodes for the corresponding tree leaves. Light > geth --syncmode=light will take about 15-20 minutes and take about 500Mb of disk space. The starting block was about 300,000 blocks behind the current block. Fast In fast mode, which is the default so no flag is required, it can take a bit of time. It gets the block headers, the block bodies, it processes no transactions until current block - 64(*). Then it gets a snapshot state and goes like a full synchronization > geth For me it took 1 hr to download 60% of the blockchain but the remaining 40% took another 5 hrs. It currently takes ~120 Gb of HDD.   Full Fully mode will take over 1Tb in storage and will take forever to sync. Currently sync’ing so TBA.   The specs of my laptop is: The Internet connection was around 50Mb/s (Wireless home fibre)   Ref: https://ethereum.stackexchange.com/questions/11297/what-is-geths-light-sync-and-why-is-it-so-fast
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Tokenization: It isn’t new but it is the future

October 2, 2018
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I had the opportunity to publish a piece in the Crypto AM publication where the audience of City A.M. (of which Crypto AM is part of) is sophisticated/high net worth/qualified City of London workers with  315,000 daily readers in print. As the Crypto winter maintains its steady grip on token prices and the ICO craze of 2017 has all but subsided, for now at least, many are wondering what to make of all these tokens that now float around in cyber space? In this article we look at the emergence of all these tokens in this tokenized economy, if the concept is really new and what’s installed in the next few years. Blockchain technology has enabled a large wave of enormous innovation with respect to the creation of these so called “utility tokens”, which are essentially promises that they can be redeemed at some point in the future for a product or a service. With over 1,600 tokens and counting, they all have created their own miniature economies battling for investors, developers and users and of course promised the masses that their Blockchain platform or application is the one that will solve the most relevant problems in today’s society. Problems […]
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Wellington Hashgraph Meetup #3

September 27, 2018
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We hosted the 3rd Wellington Hashgraph meetup a few days ago and had some international guests from around the world. About 15 people turned up so we are slowly growing (some new faces) and again, food and drinks were provided as well. We had developers Magnus Bondesson, Chi Hao Poon, Jonas Wallenius and Patrik Åkerlund join from Sweden to talk about their interesting game called BlockWars. (https://blockwars.live/) BlockWars is a map based war game running on the Ethereum blockchain and the team is looking to port this over to Hashgraph. The idea is to conquer the world by owning territory similar to the board game Risk. Above you can see Morne owning some territory in New Zealand and it was attacked by one of the BlockWars guys. Afterwards we had Shiv Aggarwal, CEO of  MyEarth.id talk about this project of creating an decentralised identity management system. It is an ambitious project and they raising capital. Afterwards, there was a good discussion about the up and coming hackathon and developers conference where we are looking to live stream the event. The next meetup is scheduled for October 17th 2018. More details can be found at: H18 – Hedera Hashgraph Developer Conference Wednesday, Oct […]
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Wellington Blockchain Meetup September 2018

September 20, 2018
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It was time for another get together of the community and to see who the true dedicated enthusiast were in amidst this crypto winter. Only about 20 people turned up but the topics were certainly very interesting. Jevon gave an update on Cryptfolio.com, a site that keeps track of your crypto portfolio, and how all your trades can be pulled from various sources to help your accountant deal with tax. Although prefaced with the disclaimer that this was not financial or legal or tax advice, in NZ, each trade is considered a taxable event and needs to be tracked. Jevon even walked through several examples and there were great questions from the audience. Jevon gave a demo of extracting a bunch of trades from various exchanges and exporting it as a CSV. Then we had Andy from Horizon State talk about their new charity app Coin Pocket (https://coinpocket.hs.app). What was interesting was a tweet from Nimo, co-founder of Horizon State. Two #blockchain meetups this week. Two different countries. Two fire alarms go off. The only thing in common was me 😂😂😂 #blockchainflowerkids in da house!? — Nimo Naamani (@nimo_ni) September 20, 2018 We had an alarm of some sort go […]
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An intro in the world of ISO/TC 307

September 13, 2018
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My first foray into the ISO world came in the form of helping companies attain ISO 9001, Total Quality Management. This is the stamp of approval indicating that a company is following good practices and procedures usually in the manufacturing industry. I spent some time looking at the ISO 27000 series when I was a briefly a Certified Information Systems Auditor (CISM) and then I learnt the entire NZ Electricity Act 1992 (the regs) and the AS/NZS 3000 for the electrical industry. Having studied (not invested unfortunately) blockchains since 2014, when ISO/TC 307 blockchains and distributed ledger technology came out I jumped at the chance to get involved. I had been in contact with Standards NZ and contributed to New Zealand upgrading its status from an O member (Observing) to a P member (Participating). It was very challenging at first because you indicate from a list of topics what interests you and your Standards body rep registers you to various groups. Then you get hammed with all sorts of emails and there is no one to help “onboard” or explain what all of this means. In May 2018 there were 7 Study Groups (SG) and 3 Work Groups (WG). ISO/TC […]
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Developments in the Blockchain Ecosystem

August 27, 2018
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This evening there was a meetup under the Decentralised Future Education Program where there was  a panel discussion about the latest development in the blockchain space covering legal aspects including jurisdictional, privacy and tax issues. The panelists were: Anand Chawra (Principal @ Boston Consulting Group) Bonnie Yiu (Co-founder @ Consulere.io) Michael Bacina (Partner @ Piper Alderman) Nick Addison (Systems Architect @ Consensys) Tom Terado (moderator) There was also Zhongxing Ming (Founder & CEO) from BlockCloud talking about  Blockchain-based Advanced TCP/IP. There was a great turn out and the food was something from the top draw! I’m sure the sponsors, Adelaide Blockchain, bitfwd, NextGenius had something to do with that!   There are two further events coming up next Monday and the Monday after so keep a look out at: https://www.meetup.com/bitfwd/
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BokkyPooBah’s Sydney Ethereum Workshop

August 24, 2018
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Bokky’s continues to run his legendary Ethereum smart contract workshop that has grown to over 700 members and it was his 82nd workshop since he’s been counting which is staggering. It would probably be in excess of 100 if he had counted from the beginning! This evening it was going back to basics talking about memory and registries of the Ethereum Virtual Machine (EVM), going through his mind map of Ethereum of Bunnies and also about FOMO3D. We all learn better when we combine individual learning with group discussions so Bokky’s contribution to the ecosystem is so vital. He is world class and I even noticed the accompanying snacks and beverages to be amazing too. Sharon Lu, the General Manager of Tyro Fintech Hub is the glue that brings everything together and does a wonderful job. To find out more about the meetup visit. https://www.meetup.com/BokkyPooBahs-Ethereum-Workshop/ Check out the mind map at: https://github.com/bokkypoobah/EthereumForBunnies There is also a forked copy of the Mastering Ethereum book (authored by Andreas Antonopoulos and Gavin Wood) in a nicer format also: https://github.com/bokkypoobah/MasteringEthereum
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Consensus protocol explained with Ethan Buchman from Tendermint

August 17, 2018
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Here is a great podcast on a bit of history of consensus protocol, what they are and how they work and also what Tendermint is and what it is useful for. Worth 60mins of your time. The transcript can be found here. Consensus Systems with Ethan Buchman
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Wellington Blockchain Meetup with NEO, Moonlight and Hyperledger

August 15, 2018
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Last night the Wellington community came together to talk blockchains at BizDojo. Some of us formed a support group to help get us through this crypto winter or crypto ice age we are experiencing at the moment also! Andrew kicked things off sharing his experience in the crypto space with some interesting stats on companies in China such as Alibaba and Tencent and how big these companies actually are. This was the basis of his interest in NEO. Next Elias Tan from Moonlight which is a decentralized platform, built on the NEO network that will change the way you recruit and scale your workforce. Elias talked about how they are using the blockchain as a means to record work experience and have it verified so that potential employers can trust someone’s work history and can also hire them based on this information instead of race, age or gender. “Trustless Hiring” it is called. For more info visit: https://moonlight.io/ Finally we had Sandy from IBM explain a bit about Hyperledger or technical Hyperledger Fabric or the “IBM Blockchain”. Here is a link for more information: https://www.ibm.com/blockchain/getting-started Thanks to BizDojo as always and if anyone has anything to share, let us know and […]
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How blockchains work

August 1, 2018
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This is a great example showing how blockchains work. Highly recommend watching it.
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First New Zealand Hashgraph Meetup

July 25, 2018
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A few nights ago Wellington held its first Hedera Hashgraph meetup to learn more about this new technology. It was very well organised with food, drinks and international guests as well. Shout out to Morne for organising the venue, food, schedule and testing all the tech to ensure a smooth meetup! Billy “Gossip Guy” from New York dialed in to give an overview of Hashgraph and some of the projects that are using Hashgraph. Then Edgar Seah (Head of Asia Pacific for Hedera) ran through some of the technical aspects of Hashgraph and how it works under the covers in terms of consensus algorithms and then Calvin Cheng, a Hashgraph developer advocate talked about the SDK and the public ledger and how one can start testing and developing using Hashgraph. For anyone interested in Hashgraph, here are some interesting links: Wellington Hashgraph Meetup Page Hedera Hashgraph Website Swirlds SDK Telegram Channel Discord (for devs)  
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Running NEM on a Raspberry Pi in 5 minutes

July 24, 2018
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A raspberry pi is a very neat device and very powerful for its size. Here is a simple guide on getting the NEM blockchain running on it in 5 minutes. What you’ll need: Raspberry Pi. I’m using the Pi 3 Model B as it has inbuilt wifi and 1Gb ram Step 1: Download NIS Visit: https://nem.io/downloads/ and download the NEM Infrastructure Server. Assuming you have ssh’d into your Raspberry Pi, I navigated to the Downloads folder and ran wget. wget https://bob.nem.ninja/nis-0.6.95.tgz You might encounter a certificate error: ERROR: The certificate of ‘bob.nem.ninja’ is not trusted. ERROR: The certificate of ‘bob.nem.ninja’ has expired. If you do, run the following: wget --no-check-certificate https://bob.nem.ninja/nis-0.6.95.tgz Step 2: Extract NIS Extract the file with: tar -xvf nis-0.6.95.tgz You will see a new package folder. cd into this folder and you’ll see a whole bunch of files. You can actually start the NEM node now if you want to run on mainnet. For testing purposes, let’s configure it for testnet. Step 3: Switching to testnet cd into nis and edit config.properties cd nis nano config.properties Look for “nem.network = mainnet” and change to “nem.network = testnet” Step 4: Start NEM Node ./nix.runNis.sh You should see the node […]
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