✅Viettel++

Blockchain 101 – A Visual Demo



This is a very basic visual introduction to the concepts behind a blockchain. We introduce the idea of an immutable ledger using an interactive web demo.

0:00 Intro
0:15 SHA256 Hash
2:18 Block
5:16 Blockchain
9:20 Distributed Blockchain
12:19 Tokens
14:36 Coinbase Transaction

Part 2 is here: https://youtu.be/xIDL_akeras

If you are interested in playing with this on your own, it is available online at:

http://anders.com/blockchain/

The code that runs this demo is also on GitHub:

https://github.com/anders94/blockchain-demo

I’m @anders94 on Twitter and @andersbrownworth on Steemit.

Donations:
BTC: 1K3NvcuZzVTueHW1qhkG2Cm3viRkh2EXJp
ETH: 0x84a90e21d9d02e30ddcea56d618aa75ba90331ff
ETC: 0xab75ad757c89fa33b92090193a797e6700769ef8

source

Giới thiệuThúy Navi

Thúy Navi 26 tuổi đam mê du lịch, công nghệ,đang sống và làm việc tại Hà Nội. Founder,Blogger tại Website: http://www.internetviettelnhatrang.com/

48 Bình luận

  1. I have had to turn comments off on my blockchain videos due to spam. If you want to reach out to me, please find me on twitter @anders94 instead.

    Most of the recent comments (which I've been judiciously deleting these past few years) have been people pushing an "I can get your private keys back for you" scam which, as everyone who has watched these videos knows. is quite impossible. I hate to take such a drastic measure but I'm afraid I just don't have the time.

  2. Where can i find more quality content like this? Im looking for good course for a computer science engineer, a technical course. Not something like "blockchain is taking over the world". I wanna know how it works and how to develop things with it.

  3. Even if I'm not a native speaker this is the best explanation I have ever received. Your ability to explain complicated things in such a simple way is amazing! I wish I had professors like you at school! Just a couple of litte questions, Anders. In the Coinbase section you list as a separate field the transaction Coinbase to Anders. First question: Do you mean Coinbase as the famous Coinbase company and so you are assuming that Anders receives money from a Coinbase transaction is his favour? What is the sense of repeating the same $100 coinbase -> Anders in all next blocks ? Why on the last block there is a $100 Coinbase ->Sophia? It seems not to make any sense as Sophia would not give out any further money to anyone in that block. Thank you very much again!

  4. hello sorry im also trying to just use your program online in a browser but i cant get it to wrok..ot says save file and i save it andnothing happens or if i try to open with i try a browser but it still saves the file ..thx if anyone can help..jessica

  5. npm ERR! Linux 4.4.0-31-generic
    npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install"
    npm ERR! node v4.2.6
    npm ERR! npm v3.5.2
    npm ERR! file sh
    npm ERR! code ELIFECYCLE
    npm ERR! errno ENOENT
    npm ERR! syscall spawn

    npm ERR! [email protected] preinstall: `node ./cyclic.js`
    npm ERR! spawn ENOENT
    npm ERR!
    npm ERR! Failed at the [email protected] preinstall script 'node ./cyclic.js'.
    npm ERR! Make sure you have the latest version of node.js and npm installed.
    npm ERR! If you do, this is most likely a problem with the typechecker package,
    npm ERR! not with npm itself.
    npm ERR! Tell the author that this fails on your system:
    npm ERR! node ./cyclic.js
    npm ERR! You can get information on how to open an issue for this project with:
    npm ERR! npm bugs typechecker
    npm ERR! Or if that isn't available, you can get their info via:
    npm ERR! npm owner ls typechecker
    npm ERR! There is likely additional logging output above.

    npm ERR! Please include the following file with any support request:
    npm ERR! /home/r1/blockchain-demo/npm-debug.log
    [email protected]:~/blockchain-demo$ npm bugs typechecker
    [email protected]:~/blockchain-demo$ cd ..
    [email protected]:~$ ls
    blockchain-demo Downloads install-cc.1 Public Videos
    Desktop examples.desktop Music s9s_tmp
    Documents install-cc Pictures Templates
    [email protected]:~$ cd blockchain-demo
    [email protected]:~/blockchain-demo$ ls
    app.js Dockerfile node_modules public views
    bin LICENSE package.json README.md
    docker-compose.yml locales package-lock.json routes
    [email protected]:~/blockchain-demo$ npm start

    > [email protected] start /home/r1/blockchain-demo
    > node ./bin/www

    sh: 1: node: not found

    npm ERR! Linux 4.4.0-31-generic
    npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "start"
    npm ERR! node v4.2.6
    npm ERR! npm v3.5.2
    npm ERR! file sh
    npm ERR! code ELIFECYCLE
    npm ERR! errno ENOENT
    npm ERR! syscall spawn
    npm ERR! [email protected] start: `node ./bin/www`
    npm ERR! spawn ENOENT
    npm ERR!
    npm ERR! Failed at the [email protected] start script 'node ./bin/www'.
    npm ERR! Make sure you have the latest version of node.js and npm installed.
    npm ERR! If you do, this is most likely a problem with the blockchain-demo package,
    npm ERR! not with npm itself.
    npm ERR! Tell the author that this fails on your system:
    npm ERR! node ./bin/www
    npm ERR! You can get information on how to open an issue for this project with:
    npm ERR! npm bugs blockchain-demo
    npm ERR! Or if that isn't available, you can get their info via:
    npm ERR! npm owner ls blockchain-demo
    npm ERR! There is likely additional logging output above.

    npm ERR! Please include the following file with any support request:
    npm ERR! /home/r1/blockchain-demo/npm-debug.log
    [email protected]:~/blockchain-demo$ ./bin/www
    /usr/bin/env: ‘node’: No such file or directory
    [email protected]:~/blockchain-demo$ node ./bin/www
    The program 'node' is currently not installed. You can install it by typing:
    sudo apt install nodejs-legacy
    [email protected]:~/blockchain-demo$ sudo apt install nodejs-legacy
    [sudo] password for r1:
    Reading package lists… Done
    Building dependency tree
    Reading state information… Done
    The following NEW packages will be installed:
    nodejs-legacy
    0 upgraded, 1 newly installed, 0 to remove and 81 not upgraded.
    Need to get 27.9 kB of archives.
    After this operation, 82.9 kB of additional disk space will be used.
    Get:1 http://us.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 nodejs-legacy all 4.2.6~dfsg-1ubuntu4.2 [27.9 kB]
    Fetched 27.9 kB in 0s (70.5 kB/s)
    Selecting previously unselected package nodejs-legacy.
    (Reading database … 195804 files and directories currently installed.)
    Preparing to unpack …/nodejs-legacy_4.2.6~dfsg-1ubuntu4.2_all.deb …
    Unpacking nodejs-legacy (4.2.6~dfsg-1ubuntu4.2) …
    Processing triggers for man-db (2.7.5-1) …
    Setting up nodejs-legacy (4.2.6~dfsg-1ubuntu4.2) …
    [email protected]:~/blockchain-demo$ node ./bin/www
    module.js:328
    throw err;
    ^

    Error: Cannot find module 'express'
    at Function.Module._resolveFilename (module.js:326:15)
    at Function.Module._load (module.js:277:25)
    at Module.require (module.js:354:17)
    at require (internal/module.js:12:17)
    at Object.<anonymous> (/home/r1/blockchain-demo/app.js:1:77)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
    at Function.Module._load (module.js:301:12)
    at Module.require (module.js:354:17)
    [email protected]:~/blockchain-demo$ npm start

    > [email protected] start /home/r1/blockchain-demo
    > node ./bin/www

    module.js:328
    throw err;
    ^

    Error: Cannot find module 'express'
    at Function.Module._resolveFilename (module.js:326:15)
    at Function.Module._load (module.js:277:25)
    at Module.require (module.js:354:17)
    at require (internal/module.js:12:17)
    at Object.<anonymous> (/home/r1/blockchain-demo/app.js:1:77)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
    at Function.Module._load (module.js:301:12)
    at Module.require (module.js:354:17)

    npm ERR! Linux 4.4.0-31-generic
    npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "start"
    npm ERR! node v4.2.6
    npm ERR! npm v3.5.2
    npm ERR! code ELIFECYCLE
    npm ERR! [email protected] start: `node ./bin/www`
    npm ERR! Exit status 1
    npm ERR!
    npm ERR! Failed at the [email protected] start script 'node ./bin/www'.
    npm ERR! Make sure you have the latest version of node.js and npm installed.
    npm ERR! If you do, this is most likely a problem with the blockchain-demo package,
    npm ERR! not with npm itself.
    npm ERR! Tell the author that this fails on your system:
    npm ERR! node ./bin/www
    npm ERR! You can get information on how to open an issue for this project with:
    npm ERR! npm bugs blockchain-demo
    npm ERR! Or if that isn't available, you can get their info via:
    npm ERR! npm owner ls blockchain-demo
    npm ERR! There is likely additional logging output above.

    npm ERR! Please include the following file with any support request:
    npm ERR! /home/r1/blockchain-demo/npm-debug.log
    [email protected]:~/blockchain-demo$ npm bugs blockchain-demo
    npm ERR! Linux 4.4.0-31-generic
    npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "bugs" "blockchain-demo"
    npm ERR! node v4.2.6
    npm ERR! npm v3.5.2
    npm ERR! code E404

    npm ERR! 404 Not found : blockchain-demo
    npm ERR! 404
    npm ERR! 404 'blockchain-demo' is not in the npm registry.
    npm ERR! 404 You should bug the author to publish it (or use the name yourself!)
    npm ERR! 404
    npm ERR! 404 Note that you can also install from a
    npm ERR! 404 tarball, folder, http url, or git url.

    npm ERR! Please include the following file with any support request:
    npm ERR! /home/r1/blockchain-demo/npm-debug.log
    [email protected]:~/blockchain-demo$
    *hello i tried running your source code with the steps from github page but i get the erors above* Jessica

  6. hello i am trying to run the code in cygwin and i am getting this error….**SyntaxError: Invalid or unexpected token
    at Module._compile (internal/modules/cjs/loader.js:723:23)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Module.require (internal/modules/cjs/loader.js:692:17)
    at require (internal/modules/cjs/helpers.js:25:18)
    at Object.<anonymous> (C:cygwin64homeTommy Robertblockchain-demoapp.js:9:14)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)**…..would you know how to solve this?..i am on a win dows 7 machine..should i try to run it on VMware ubuntu machine?,,thxz for your great vid…Jesiica

  7. Hey Anders, great work! But I have a question. Suppose we have three peers such as in your example. Let say Peer A and Peer B make same changes on the latest Block (Let say the write a completly egual addittional message in the data field) and they mine it afterwards to get a valid blockchain. So at the end we have three valid blockchains, but we know that the chains of A and B are the same but C is different. We also know, that C is the right one, but it looks like that C is manipulated, because it doesnt match with A and B. Would this scenario represent a perfect manipulation approach? When not, how can the system know that C is the right one and not A and B?

  8. Lots of news articles saying this can be a tool to evade censorship in china. Because how do you hide information? Everything you see on the computer screen are data (more explicitly, bits; zeroes and ones internally), which can be assigned to a hash, and to censor it requires tampering it, which will alter the hash and destroys the later blocks in the chain, the government can no longer view information of all the later blocks, and re-mining it does fix the chain, but does not reattaches the blocks being disconnected. Essentially you broke a real chain, reattach to the one you just created. Looks like if the government wants TRUE censorship that is unstoppable, that is only possible by removing the internet entirely, force all citizens and foreigners not to use computers that allow circumventions, and/or use the intranet.

Trả lời

Email của bạn sẽ không được hiển thị công khai.