#why does cps make transparent images look like that

[catgirlweed]

flat worlds/flat minds

[capechicago]

CAPE Network Forum Newsletter: Issue II

Students at New Sullivan Elementary’s CAPE After School program led by Jordan Knecht and Darlene Carothers learned how to “glitch” digital images by tampering with computer codes to create original art pieces.

Welcome to the second edition of the CAPE Network Forum Newsletter. In this edition you will find the voices of teachers, artists and CAPE staff exploring the new reality in which we find ourselves, a reality that places us all in an unknown and undefined relational space. As William Estrada expressed in a recent CAPE Network Forum post, “I am a big supporter of public education and teaching in front of students in their neighborhood schools, so jumping into remote teaching feels so disconnected for me.”

William is not alone in that sentiment but as he aptly points out, this moment also offers a learning opportunity for us all: “I am curious how this experience will shape our thinking about making mistakes, thinking out loud what our artistic and teaching practice is and what we want it to look like with others. These videos are meant to remind us what art can do, and what we can do with art and I am excited to learn more about it with others in these uncertain times.” Additionally, this moment asks us to collectively question how we all relate to one another and how we form a network.

For years, CAPE has explored the concepts and the interactions of space and identity as a network. Through aesthetic and pedagogical explorations, we have examined the ways in which spaces are both physical and how they are also the constructs of our social interactions. In the context of a school building or a neighborhood, CAPE teachers and teaching artists along with their students have re-imagined and redefined spaces, creating new paradigms that flatten hierarchies amongst participants through art making and dialogue. In some cases, this has involved changing the physicality of a space by painting staircases (see full documentation of that project here) or rearranging furniture. In other cases, the spaces are co-constructed by altering the political and power structures within school spaces wherein teachers, artists and students engage in shared inquiry that follows uncharted trajectories, where there is no “expert” in the room, only a group of collaborating thinkers and doers.

Working in digital spaces is not a new concept for many CAPE teachers, artists and students. In 2018, CAPE program staff partnered with researcher partners Dr. Louanne Smolin and Erin Preston to co-write a chapter in the book Negotiating Place and Space through Digital Literacies entitled “Digital Media Explorations: How Space and Identity Become Sources of Learning.” In it, past examples of CAPE school-based projects illustrated how “CAPE teachers and artists co-created curriculum that diverged from the linearity of instruction, conceiving of digital technology as material to produce space and identity creating opportunities for all to better understand the world and themselves.”

However, the lack of person to person physical interactions still raises many questions

about what is possible for the construction of identity in relation to the co-creation of space. How will we as a network navigate this current scenario and maintain upholding the value of shared envisioning of teaching, learning and arts practice? How can we co- create digital spaces in a way that allows for exploration of content and material? And how do we as a network share our insights and learn together in ways that are relevant right now, but also for the future of our shared work?

— Joseph Spilberg

Updates

On April 12, Chicago Public Schools central office issued a prohibition on external guests joining in virtual learning lessons. This would prevent CAPE teaching artists joining live, online instruction happening in students’ homes. This should not prevent sharing pre-recorded artist instructional videos for students, nor should it prevent take-home instructions for students. CAPE program staff is seeking further information and clarifications on this policy. CPS central office has also issued a best practices document to parents on live virtual learning, and provided suggestions as to different platforms for remote and online learning. Individual schools know best which platforms they are using and how they are using it. Artists must consult with their teacher partners as to how students receive pre-recorded videos or take-home instructions.

CPS central office has out a guide for accessing internet from various providers:

https://docs.google.com/document/d/1ejwEUTt56mDdcNUDQ2oLFlL--qhC3qe- lhlOe5mD4gs/edit

State Superintendent of Education Dr. Ayala’s message for April 13 includes an interactive map for finding drive-up wifi hotspots (http://illinois.maps.arcgis.com/apps/webappviewer/index.html? id=23e8046edd2940bc8ad3ad1725e47cd0). In addition, she asks schools and other public institutions who may have wifi accessible from their building to fill out this survey: https://survey123.arcgis.com/share/7dabc7cdbd7149d3ab49254568295502

The Artists For Illinois Relief Fund (AIRF) will open for applications again on Monday, May 4. Artists who wish to receive information and email notification when the application reopens should go to https://3arts.org/news/airf-artists/.

CAPE Network Forum Tumblr Highlight:

This week's Tumblr highlight is a video produced by teaching artist Shenequa Brooks and New Sullivan Elementary School teacher Jacquelyn Limon. Here, Brooks and Limon are filming in split screen, a prime example of co-teaching in the digital space. Click to see their channel.

CAPE Network Interview: William Estrada, Interviewed by Jenny Lee

William Estrada was born to immigrant parents and grew up in California, Chicago, and Mexico. His teaching and art making practice focus on exploring inequality, migration, historical passivity, cultural recognition, self-preservation, and media representation in under-represented communities. He documents and engages experiences in public spaces to transform, question, and make connections to established and organic systems through discussion, creation, and amplification of stories already present. He is currently a visual art teacher at Telpochcalli Elementary School and faculty at the School of Arts and Art History at UIC. He has worked as an educator at many organizations, including as an Artist/Researcher with CAPE since 2002.

Your most recent CAPE Network Forum video was on a read-aloud on the book The Table Where Rich People Sit. Why did you choose this book, and how does it resonate with you in general and during this pandemic?

I’m trying to figure out how to have conversations that we’d usually have at Telpochcalli. How do we start reframing what art education looks like and what it can do.

The Table Where Rich People Sit is about thinking about inequality and wages, but it’s also exploring the idea of decolonizing wealth and what we value. Especially when we think about invisible labor, and who is considered essential workers right now and who was considered essential workers four weeks ago. The online videos themselves are meant to be a reflection of conversations that I would have with students anyway. It’s also a way for me, as an adult, as a teacher, as a parent, and as a community member, to amplify voices that are missing in these discussions.

How have you centered play and experimentation in your projects now?

I’m trying to make videos with intention and me playing, both with the technology and the content. I’m specifically thinking about the audience. I primarily teach elementary

students, so I’m trying to figure out how to engage in conversations with younger audiences, but the content isn’t distilled. That’s how I teach anyway, but I’m really trying to figure out how to play around with words and concepts, like being read to. I’m trying to curate the books that I read. How do we use stories to address inequality? Who generates knowledge? Whose stories get to be told? Those are all conversations that I try to have with elementary age students that I teach, but they’re also conversations that I have in studio courses at the college level. It’s about access to culture, power, and resources.

How do you see community support during this time?

I’m specifically thinking of myself as a cis-Latino male. We’re constantly thinking of ourselves as strong, like we’ll get through this. But what does it mean for me to be afraid? And how do we begin to have these discussions about being transparent, vulnerable, and complex. This is what makes us who we are. And this is how we take care of each other. We don’t have all the answers, but the answers that we do have, they can comfort others. And the fears that we have, others can comfort us. This is what it’s like being in a collective. This is what we do everyday, and this is what relationships are. But in this moment in time, it’s allowed us to be more transparent and intentional, and thanking those that make us feel safe and take care of us. This is a moment to remind people that they’re important to us.

Telpochcalli Community Education Project (TCEP) is really coming together as a community to self-organize and help others gather resources that they might not have the connections to, like diapers and formula. TCEP has always done community organizing, but now all these efforts are condensed into one, and these are our immediate needs. It’s been really amazing to see the love and the hard work that’s taking place, but it’s also disheartening because the inequality that existed in the city was present before, but with this pandemic it’s being emphasized tenfold. Who has access to food? Who is able to wash their clothes?

How have you seen collaboration change?

It’s not the same. The meaning for me to teach comes from the relationships that are formed. The relationships are different when we aren’t necessarily in the same room. It obviously makes it more accessible to others, and we can document what we’re teaching. It’s good. But I feel like it’s one-way. I’m not responding to people’s comments or facial expressions. If I’m filming a video, I can sit and talk for three hours. But in a classroom, I would break it down because I would see students and adults wiggling in their seats...

Right now, the projects are very one directional. They’re very “This is what I want!” But when we’re teaching collaboratively, I usually introduce ideas, and I have an idea on what the final project might look like, but we never end up with that project. The students know that they’re collaborators. They’re part of that creative process. It helps to come in with an idea and structure, but you know that idea and structure are going to change based on the responsiveness of the people in front of you, and that’s kind of missing right now. I really enjoy being with others and creating with others. It’s missing -- the conversation that we have with our bodies.

Beginning in the 2000s, CAPE began to see itself as a network. You are part of that network, and you are on the CAPE Board. How do you see the CAPE network in relation to the present crisis?

The CAPE network has been essential in forming and informing the relationships that have been created. One part is the extensive network of artists, teachers, administrators, and schools that has really helped in getting off the ground these remote learning plans. Without these relationships that CAPE has built, it would be so hard to do. The other part is that because CAPE has created professional developments and is in constant communication with all the teachers and artists about needs, about new ways of thinking about our own practice, about how to deliver that practice, it hasn’t been as difficult to reframe what our teaching can look like. Obviously there are still challenges around technologies and accessibility, but I think the underlying threads and foundations that we’ve been dealing with for a really long time: relevancy to the schools we’re teaching, how we’re being responsive to the needs of our particular communities, what resources we’re using....all of this has been so transparent as we’ve been transitioning. It’s CAPE’s model that has been changing, but ongoing, that has alleviated some of the pressure and stress of what we could potentially do because we’ve been doing it all along. The only difference is how it’s being delivered.

As a CAPE board member, as all this was happening and having these conversations about how to support the teaching artists was really heartfelt for me -- being able to make that commitment to support the artists no matter what happens. We’re shaping what art education is, and we’re shaping how other people see art education, not only as an organization but as teachers and artists.

Contemporary Recall:

Written by: Scott Sikkema

In the spring of 2012, Mark Diaz and I planned a session to look at archives/archiving for a group of teaching artists. We looked at the frameworks through which archives are seen, and how the teaching artists can think about archiving in their own practice and how they represent their own work to others.

In order to get at these notions and questions around archiving, Mark and I first met with Karen Kanemoto from the Japanese American Service Committee (JASC). The JASC was formed after World War II to provide support services for Japanese Americans relocated to the Chicago area after having been incarcerated in internment camps during the war. The JASC has extensive holdings of documents, artifacts, photographs, and other material relating to the Japanese American experience prior to coming to the U.S., early years in the U.S., World War II and the internment camps, and post-war life. With Karen, we looked through a portion of the archives, and settled on a selection of materials.

We asked ourselves, how do we look at these powerful materials in such a way as to build the artists’ capacity to look at themselves and what they generate out of their own practice, and, if they archive, how is that archive used and what can it say to others?

This was not an easy task. After much discussion, Mark and I determined that we should ourselves select what we thought were key frameworks for looking at an archive. Following are the frameworks, with the short definitions we provided the artists:

Big Idea (Some archives represent an overarching big idea, such as World War II, internment, diaspora, etc.)

Personal Stories (Within archives there are often potent and compelling stories of individual people.)

Institutional (Within archives there are often legal documents and processes, which, while official, give another sense of how people were living or how conditions were or were not functioning.)

Taxonomy/ways of categorizing (An archive often uses an organizing system, also known as a taxonomy. Taxonomies provide viewers with a variety of ways to approach and begin exploring the materials contained in an archive. Taxonomies are either naturally dictated by the materials, or are constructed by the archivist.)

Site (While some archives are more geared towards the temporal, other archives capture all the different aspects of a site, including the space, people, physicality, objects, relationships, and more.)

Once we settled on these frameworks, our next challenge was how to explore them, in relation to two things: the JASC artifacts, and the artists themselves (their self reflection). This again proved a debate, but it finally settled us into the final format of the workshop we led at the JASC.

Mark, Karen, and I chose artifacts that were varied in a number of ways. They varied in their physicality: some pieces were in journal/scrapbook form, some were photo stock paper, some were thin and fragile newsprint, etc. They varied in the nature of their content: some were official documents, some were personal, some were text, some were images, and some were commercial ephemera. They were also varied in terms of their levels of accessibility, i.e., some artifacts were not easy to decipher, and some had little or no visual appeal.

The artifacts were divided up into 10 tables. The participants were divided up into groups of two. Each pair went to a table. They were given timed intervals to be at a table, and then we would tell them to switch. During their time there, they would examine the artifacts, and discuss and debate them. Mark and I gave them framework analysis worksheets, using the overarching ideas listed above. For each overarching idea, such as “Site” or “Institutional”, they were also provided with a series of questions to understand the artifacts/archive through that framework, and after that questions to transfer that framework over to how they think about their own archive of work.

In education, we (arts organizations or other similar bodies) often ask teachers or students or teaching artists to document their work, to collect samples, and to write short explanations. That documentation often is used by the organization for its own purposes. Sometimes it is used by the teacher and/or teaching artists to tell the story of what they did. Both of those results have their value. But in our own work, or looking at the work of others, how often do we pull back and try to look at an individual piece or fragments of work? How often do we try to look at the work as a collective accumulation, without immediately forcing it into a story, or into a narrative of what we want?How can we build on collective knowledge by collectively examining an archive? How often do we clearly think about the frameworks we inherently almost always bring to looking at artifacts and archives? How often do we ask ourselves, what other frameworks are possible?

Questions like these can allow us to take more time to become more open to what archives, artifacts, and documentation can say to us, and what meanings they might hold beyond the particular meaning we have predetermined. Questions like this can also help us examine closely how we ourselves actually produce artifacts for our own archives, what constitutes an artifact itself for inclusion, and how one artifact relates or does not relate (without value judgments) to another.

Looking back on this workshop, I am also thinking about what might resonate today, about life before and during the pandemic, our relationships, what artifacts we generate or encounter, and how we frame meaning from this.

CAPE Program Staff:

Scott Sikkema, Education Director (scott@capechicago.org) Mark Diaz, Associate Director of Education (mark@capechicago.org) Joseph Spilberg, Associate Director of Education (joseph@capechicago.org) Brandon Phouybanhdyt, Program Coordinator (brandon@capechicago.org) Jenny Lee, Research Program Coordinator (jenny@capechicago.org)

[johanlouwers]

Blockchain, Part II: Configuring a Blockchain Network and Leveraging the Technology

Blockchain, Part II: Configuring a Blockchain Network and Leveraging the Technology

Image

Petros Koutoupis Tue, 04/24/2018 - 11:30

Blockchain

HOW-TOs

Cryptocurrency

Cryptominig

How to set up a private ethereum blockchain using open-source tools and a look at some markets and industries where blockchain technologies can add value.

In Part I, I spent quite a bit of time exploring cryptocurrency and the mechanism that makes it possible: the blockchain. I covered details on how the blockchain works and why it is so secure and powerful. In this second part, I describe how to set up and configure your very own private ethereum blockchain using open-source tools. I also look at where this technology can bring some value or help redefine how people transact across a more open web.

Setting Up Your Very Own Private Blockchain Network

In this section, I explore the mechanics of an ethereum-based blockchain network—specifically, how to create a private ethereum blockchain, a private network to host and share this blockchain, an account, and then how to do some interesting things with the blockchain.

What is ethereum, again? Ethereum is an open-source and public blockchain platform featuring smart contract (that is, scripting) functionality. It is similar to bitcoin but differs in that it extends beyond monetary transactions.

Smart contracts are written in programming languages, such as Solidity (similar to C and JavaScript), Serpent (similar to Python), LLL (a Lisp-like language) and Mutan (Go-based). Smart contracts are compiled into EVM (see below) bytecode and deployed across the ethereum blockchain for execution. Smart contracts help in the exchange of money, property, shares or anything of value, and it does so in a transparent and conflict-free way avoiding the traditional middleman.

If you recall from Part I, a typical layout for any blockchain is one where all nodes are connected to every other node, creating a mesh. In the world of ethereum, these nodes are referred to as Ethereum Virtual Machines (EVMs), and each EVM will host a copy of the entire blockchain. Each EVM also will compete to mine the next block or validate a transaction. Once the new block is appended to the blockchain, the updates are propagated to the entire network, so that each node is synchronized.

In order to become an EVM node on an ethereum network, you'll need to download and install the proper software. To accomplish this, you'll be using Geth (Go Ethereum). Geth is the official Go implementation of the ethereum protocol. It is one of three such implementations; the other two are written in C++ and Python. These open-source software packages are licensed under the GNU Lesser General Public License (LGPL) version 3. The standalone Geth client packages for all supported operating systems and architectures, including Linux, are available here. The source code for the package is hosted on GitHub.

Geth is a command-line interface (CLI) tool that's used to communicate with the ethereum network. It's designed to act as a link between your computer and all other nodes across the ethereum network. When a block is being mined by another node on the network, your Geth installation will be notified of the update and then pass the information along to update your local copy of the blockchain. With the Geth utility, you'll be able to mine ether (similar to bitcoin but the cryptocurrency of the ethereum network), transfer funds between two addresses, create smart contracts and more.

Download and Installation

In my examples here, I'm configuring this ethereum blockchain on the latest LTS release of Ubuntu. Note that the tools themselves are not restricted to this distribution or release.

Downloading and Installing the Binary from the Project Website

Download the latest stable release, extract it and copy it to a proper directory:

$ wget https://gethstore.blob.core.windows.net/builds/ ↪geth-linux-amd64-1.7.3-4bb3c89d.tar.gz $ tar xzf geth-linux-amd64-1.7.3-4bb3c89d.tar.gz $ cd geth-linux-amd64-1.7.3-4bb3c89d/ $ sudo cp geth /usr/bin/

Building from Source Code

If you are building from source code, you need to install both Go and C compilers:

$ sudo apt-get install -y build-essential golang

Change into the directory and do:

$ make geth

Installing from a Public Repository

If you are running on Ubuntu and decide to install the package from a public repository, run the following commands:

$ sudo apt-get install software-properties-common $ sudo add-apt-repository -y ppa:ethereum/ethereum $ sudo apt-get update $ sudo apt-get install ethereum

Getting Started

Here is the thing, you don't have any ether to start with. With that in mind, let's limit this deployment to a "private" blockchain network that will sort of run as a development or staging version of the main ethereum network. From a functionality standpoint, this private network will be identical to the main blockchain, with the exception that all transactions and smart contracts deployed on this network will be accessible only to the nodes connected in this private network. Geth will aid in this private or "testnet" setup. Using the tool, you'll be able to do everything the ethereum platform advertises, without needing real ether.

Remember, the blockchain is nothing more than a digital and public ledger preserving transactions in their chronological order. When new transactions are verified and configured into a block, the block is then appended to the chain, which is then distributed across the network. Every node on that network will update its local copy of the chain to the latest copy. But you need to start from some point—a beginning or a genesis. Every blockchain starts with a genesis block, that is, a block "zero" or the very first block of the chain. It will be the only block without a predecessor. To create your private blockchain, you need to create this genesis block. To do this, you need to create a custom genesis file and then tell Geth to use that file to create your own genesis block.

Create a directory path to host all of your ethereum-related data and configurations and change into the config subdirectory:

$ mkdir ~/eth-evm $ cd ~/eth-evm $ mkdir config data $ cd config

Open your preferred text editor and save the following contents to a file named Genesis.json in that same directory:

{ "config": { "chainId": 999, "homesteadBlock": 0, "eip155Block": 0, "eip158Block": 0 }, "difficulty": "0x400", "gasLimit": "0x8000000", "alloc": {} }

This is what your genesis file will look like. This simple JSON-formatted string describes the following:

config — this block defines the settings for your custom chain.

chainId — this identifies your Blockchain, and because the main ethereum network has its own, you need to configure your own unique value for your private chain.

homesteadBlock — defines the version and protocol of the ethereum platform.

eip155Block / eip158Block — these fields add support for non-backward-compatible protocol changes to the Homestead version used. For the purposes of this example, you won't be leveraging these, so they are set to "0".

difficulty — this value controls block generation time of the blockchain. The higher the value, the more calculations a miner must perform to discover a valid block. Because this example is simply deploying a test network, let's keep this value low to reduce wait times.

gasLimit — gas is ethereum's fuel spent during transactions. As you do not want to be limited in your tests, keep this value high.

alloc — this section prefunds accounts, but because you'll be mining your ether locally, you don't need this option.

Now it's time to instantiate the data directory. Open a terminal window, and assuming you have the Geth binary installed and that it's accessible via your working path, type the following:

$ geth --datadir /home/petros/eth-evm/data/PrivateBlockchain ↪init /home/petros/eth-evm/config/Genesis.json WARN [02-10|15:11:41] No etherbase set and no accounts found ↪as default INFO [02-10|15:11:41] Allocated cache and file handles ↪database=/home/petros/eth-evm/data/PrivateBlockchain/ ↪geth/chaindata cache=16 handles=16 INFO [02-10|15:11:41] Writing custom genesis block INFO [02-10|15:11:41] Successfully wrote genesis state ↪database=chaindata hash=d1a12d...4c8725 INFO [02-10|15:11:41] Allocated cache and file handles ↪database=/home/petros/eth-evm/data/PrivateBlockchain/ ↪geth/lightchaindata cache=16 handles=16 INFO [02-10|15:11:41] Writing custom genesis block INFO [02-10|15:11:41] Successfully wrote genesis state ↪database=lightchaindata

The command will need to reference a working data directory to store your private chain data. Here, I have specified eth-evm/data/PrivateBlockchain subdirectories in my home directory. You'll also need to tell the utility to initialize using your genesis file.

This command populates your data directory with a tree of subdirectories and files:

$ ls -R /home/petros/eth-evm/ .: config data ./config: Genesis.json ./data: PrivateBlockchain ./data/PrivateBlockchain: geth keystore ./data/PrivateBlockchain/geth: chaindata lightchaindata LOCK nodekey nodes transactions.rlp ./data/PrivateBlockchain/geth/chaindata: 000002.ldb 000003.log CURRENT LOCK LOG MANIFEST-000004 ./data/PrivateBlockchain/geth/lightchaindata: 000001.log CURRENT LOCK LOG MANIFEST-000000 ./data/PrivateBlockchain/geth/nodes: 000001.log CURRENT LOCK LOG MANIFEST-000000 ./data/PrivateBlockchain/keystore:

Your private blockchain is now created. The next step involves starting the private network that will allow you to mine new blocks and have them added to your blockchain. To do this, type:

petros@ubuntu-evm1:~/eth-evm$ geth --datadir ↪/home/petros/eth-evm/data/PrivateBlockchain --networkid 9999 WARN [02-10|15:11:59] No etherbase set and no accounts found ↪as default INFO [02-10|15:11:59] Starting peer-to-peer node ↪instance=Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.2 INFO [02-10|15:11:59] Allocated cache and file handles ↪database=/home/petros/eth-evm/data/PrivateBlockchain/ ↪geth/chaindata cache=128 handles=1024 WARN [02-10|15:11:59] Upgrading database to use lookup entries INFO [02-10|15:11:59] Initialised chain configuration ↪config="{ChainID: 999 Homestead: 0 DAO: DAOSupport: ↪false EIP150: EIP155: 0 EIP158: 0 Byzantium: ↪Engine: unknown}" INFO [02-10|15:11:59] Disk storage enabled for ethash caches ↪dir=/home/petros/eth-evm/data/PrivateBlockchain/ ↪geth/ethash count=3 INFO [02-10|15:11:59] Disk storage enabled for ethash DAGs ↪dir=/home/petros/.ethash count=2 INFO [02-10|15:11:59] Initialising Ethereum protocol ↪versions="[63 62]" network=9999 INFO [02-10|15:11:59] Database deduplication successful ↪deduped=0 INFO [02-10|15:11:59] Loaded most recent local header ↪number=0 hash=d1a12d...4c8725 td=1024 INFO [02-10|15:11:59] Loaded most recent local full block ↪number=0 hash=d1a12d...4c8725 td=1024 INFO [02-10|15:11:59] Loaded most recent local fast block ↪number=0 hash=d1a12d...4c8725 td=1024 INFO [02-10|15:11:59] Regenerated local transaction journal ↪transactions=0 accounts=0 INFO [02-10|15:11:59] Starting P2P networking INFO [02-10|15:12:01] UDP listener up ↪self=enode://f51957cd4441f19d187f9601541d66dcbaf560 ↪770d3da1db4e71ce5ba3ebc66e60ffe73c2ff01ae683be0527b77c0f96 ↪a178e53b925968b7aea824796e36ad27@[::]:30303 INFO [02-10|15:12:01] IPC endpoint opened: /home/petros/eth-evm/ ↪data/PrivateBlockchain/geth.ipc INFO [02-10|15:12:01] RLPx listener up ↪self=enode://f51957cd4441f19d187f9601541d66dcbaf560 ↪770d3da1db4e71ce5ba3ebc66e60ffe73c2ff01ae683be0527b77c0f96 ↪a178e53b925968b7aea824796e36ad27@[::]:30303

Notice the use of the new parameter, networkid. This networkid helps ensure the privacy of your network. Any number can be used here. I have decided to use 9999. Note that other peers joining your network will need to use the same ID.

Your private network is now live! Remember, every time you need to access your private blockchain, you will need to use these last two commands with the exact same parameters (the Geth tool will not remember it for you):

$ geth --datadir /home/petros/eth-evm/data/PrivateBlockchain ↪init /home/petros/eth-evm/config/Genesis.json $ geth --datadir /home/petros/eth-evm/data/PrivateBlockchain ↪--networkid 9999

Configuring a User Account

So, now that your private blockchain network is up and running, you can start interacting with it. But in order to do so, you need to attach to the running Geth process. Open a second terminal window. The following command will attach to the instance running in the first terminal window and bring you to a JavaScript console:

$ geth attach /home/petros/eth-evm/data/PrivateBlockchain/geth.ipc Welcome to the Geth JavaScript console! instance: Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.2 modules: admin:1.0 debug:1.0 eth:1.0 miner:1.0 net:1.0 ↪personal:1.0 rpc:1.0 txpool:1.0 web3:1.0 >

Time to create a new account that will manipulate the Blockchain network:

> personal.newAccount() Passphrase: Repeat passphrase: "0x92619f0bf91c9a786b8e7570cc538995b163652d"

Remember this string. You'll need it shortly. If you forget this hexadecimal string, you can reprint it to the console by typing:

> eth.coinbase "0x92619f0bf91c9a786b8e7570cc538995b163652d"

Check your ether balance by typing the following script:

> eth.getBalance("0x92619f0bf91c9a786b8e7570cc538995b163652d") 0

Here's another way to check your balance without needing to type the entire hexadecimal string:

> eth.getBalance(eth.coinbase) 0

Mining

Doing real mining in the main ethereum blockchain requires some very specialized hardware, such as dedicated Graphics Processing Units (GPU), like the ones found on the high-end graphics cards mentioned in Part I. However, since you're mining for blocks on a private chain with a low difficulty level, you can do without that requirement. To begin mining, run the following script on the JavaScript console:

> miner.start() null

Updates in the First Terminal Window

You'll observe mining activity in the output logs displayed in the first terminal window:

INFO [02-10|15:14:47] Updated mining threads ↪threads=0 INFO [02-10|15:14:47] Transaction pool price threshold ↪updated price=18000000000 INFO [02-10|15:14:47] Starting mining operation INFO [02-10|15:14:47] Commit new mining work ↪number=1 txs=0 uncles=0 elapsed=186.855us INFO [02-10|15:14:57] Generating DAG in progress ↪epoch=1 percentage=0 elapsed=7.083s INFO [02-10|15:14:59] Successfully sealed new block ↪number=1 hash=c81539...dc9691 INFO [02-10|15:14:59] mined potential block ↪number=1 hash=c81539...dc9691 INFO [02-10|15:14:59] Commit new mining work ↪number=2 txs=0 uncles=0 elapsed=211.208us INFO [02-10|15:15:04] Generating DAG in progress ↪epoch=1 percentage=1 elapsed=13.690s INFO [02-10|15:15:06] Successfully sealed new block ↪number=2 hash=d26dda...e3b26c INFO [02-10|15:15:06] mined potential block ↪number=2 hash=d26dda...e3b26c INFO [02-10|15:15:06] Commit new mining work ↪number=3 txs=0 uncles=0 elapsed=510.357us [ ... ] INFO [02-10|15:15:52] Generating DAG in progress ↪epoch=1 percentage=8 elapsed=1m2.166s INFO [02-10|15:15:55] Successfully sealed new block ↪number=15 hash=d7979f...e89610 INFO [02-10|15:15:55] block reached canonical chain ↪number=10 hash=aedd46...913b66 INFO [02-10|15:15:55] mined potential block ↪number=15 hash=d7979f...e89610 INFO [02-10|15:15:55] Commit new mining work ↪number=16 txs=0 uncles=0 elapsed=105.111us INFO [02-10|15:15:57] Successfully sealed new block ↪number=16 hash=61cf68...b16bf2 INFO [02-10|15:15:57] block reached canonical chain ↪number=11 hash=6b89ff...de8f88 INFO [02-10|15:15:57] mined potential block ↪number=16 hash=61cf68...b16bf2 INFO [02-10|15:15:57] Commit new mining work ↪number=17 txs=0 uncles=0 elapsed=147.31us

Back to the Second Terminal Window

Wait 10–20 seconds, and on the JavaScript console, start checking your balance:

> eth.getBalance(eth.coinbase) 10000000000000000000

Wait some more, and list it again:

> eth.getBalance(eth.coinbase) 75000000000000000000

Remember, this is fake ether, so don't open that bottle of champagne, yet. You are unable to use this ether in the main ethereum network.

To stop the miner, invoke the following script:

> miner.stop() true

Well, you did it. You created your own private blockchain and mined some ether.

Who Will Benefit from This Technology Today and in the Future?

Although the blockchain originally was developed around cryptocurrency (more specifically, bitcoin), its uses don't end there. Today, it may seem like that's the case, but there are untapped industries and markets where blockchain technologies can redefine how transactions are processed. The following are some examples that come to mind.

Improving Smart Contracts

Ethereum, the same open-source blockchain project deployed earlier, already is doing the whole smart-contract thing, but the idea is still in its infancy, and as it matures, it will evolve to meet consumer demands. There's plenty of room for growth in this area. It probably and eventually will creep into governance of companies (such as verifying digital assets, equity and so on), trading stocks, handling intellectual property and managing property ownership, such as land title registration.

Enabling Market Places and Shared Economies

Think of eBay but refocused to be peer-to-peer. This would mean no more transaction fees, but it also will emphasize the importance of your personal reputation, since there will be no single body governing the market in which goods or services are being traded or exchanged.

Crowdfunding

Following in the same direction as my previous remarks about a decentralized marketplace, there also are opportunities for individuals or companies to raise the capital necessary to help "kickstart" their initiatives. Think of a more open and global Kickstarter or GoFundMe.

Multimedia Sharing or Hosting

A peer-to-peer network for aspiring or established musicians definitely could go a long way here—one where the content will reach its intended audiences directly and also avoid those hefty royalty costs paid out to the studios, record labels and content distributors. The same applies to video and image content.

File Storage and Data Management

By enabling a global peer-to-peer network, blockchain technology takes cloud computing to a whole new level. As the technology continues to push itself into existing cloud service markets, it will challenge traditional vendors, including Amazon AWS and even Dropbox and others—and it will do so at a fraction of the price. For example, cold storage data offerings are a multi-hundred billion dollar market today. By distributing your encrypted archives across a global and decentralized network, the need to maintain local data-center equipment by a single entity is reduced significantly.

Social media and how your posted content is managed would change under this model as well. Under the blockchain, Facebook or Twitter or anyone else cannot lay claim to what you choose to share.

Another added benefit to leveraging blockchain here is making use of the cryptography securing your valuable data from getting hacked or lost.

Internet of Things

What is the Internet of Things (IoT)? It is a broad term describing the networked management of very specific electronic devices, which include heating and cooling thermostats, lights, garage doors and more. Using a combination of software, sensors and networking facilities, people can easily enable an environment where they can automate and monitor home and/or business equipment.

Supply Chain Audits

With a distributed public ledger made available to consumers, retailers can't falsify claims made against their products. Consumers will have the ability to verify their sources, be it food, jewelry or anything else.

Identity Management

There isn't much to explain here. The threat is very real. Identity theft never takes a day off. The dated user name/password systems of today have run their course, and it's about time that existing authentication frameworks leverage the cryptographic capabilities offered by the blockchain.

Summary

This revolutionary technology has enabled organizations in ways that weren't possible a decade ago. Its possibilities are enormous, and it seems that any industry dealing with some sort of transaction-based model will be disrupted by the technology. It's only a matter of time until it happens.

Now, what will the future for blockchain look like? At this stage, it's difficult to say. One thing is for certain though; large companies, such as IBM, are investing big into the technology and building their own blockchain infrastructure that can be sold to and used by corporate enterprises and financial institutions. This may create some issues, however. As these large companies build their blockchain infrastructures, they will file for patents to protect their technologies. And with those patents in their arsenal, there exists the possibility that they may move aggressively against the competition in an attempt to discredit them and their value.

Anyway, if you will excuse me, I need to go make some crypto-coin.

https://ift.tt/2qXdL6a via @johanlouwers . follow me also on twitter