We have created the Azure Blockchain Service to store a data securely. But we need a way to write and read the data from Transaction Node.
As of now, we can store the data in Transaction node using HTTP Post method as per this article
https://tsmatz.wordpress.com/2019/11/06/azure-blockchain-service-quorum-tutorial-web3-truffle-develop/
But how to read the same data again from Transaction Node?
After a couple of weeks of study, I realized that we need to write smart contracts to read and write data to blockchain.
Truffle Framework provides a suite of tools for developing Ethereum smart contracts with the Solidity programming language.
Web3.js library, the main JavaScript library for interacting with the Ethereum Blockchain.
Thanks to Gregory McCubbin, a Ethereum Development Expert from Dapp University who explains the Ethereum blockchain in a very effective manner.
https://www.dappuniversity.com/articles/blockchain-app-tutorial
The good news with azure blockchain service is that you can use Azure Blockchain Development Kit for Ethereum VS Code extension to attach to a consortium, create, connect, build, and deploy smart contracts on Ethereum blockchain ledgers.
https://learn.microsoft.com/en-us/azure/blockchain/service/connect-vscode
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I'm developing a nodejs application and trying to integrate blockchain in it. Here in my application, I want to create a blockchain where only the server (my app) can create blocks. The blockchain is public and anyone can view it. I just need a simple way to store this blockchain publically and everyone has the read permission.
With my limited knowledge, I have created a system using node and MongoDB. where each block is stored as a document in db. using an api anyone can view the database, which didn't work.
Which backend technology should i use to get this done? Which specific npm modules should into?
There are three types of blockchain Public Blockchain, Private Blockchain and Consortium Blockchain. What you want is the Consortium Blockchain in which you can have a Control on blockchain and it is semi decentralised.
To interact with the blockchain to Show all the data you have to make the distributted application and use the Web3 Libraray to interact with blockchain.
So all your data can be Access through web3 library api and you Show it to your app. Through that anyone can see the data publicly.
I’m interested into the development of Blockchain Apps using Fabric and Composer.
I’ve got just one question: while Ethereum is a public blockchain so you can deploy your Smart Contract on it and use them freely, can we do the same thing with Fabric? Let me explain: Ethereum has a running Blockchain on which we can work and access, but Fabric has not, right? Should I set up an entire new blockchain network before (setting up all the nodes, giving permissions etc.)?
Thank you
Hyperledger Fabric is different to the blockchain systems you mention in it is private and permissioned. Rather than an open permissionless system that allows unknown identities to participate in the network (requiring protocols like “proof of work” to validate transactions and secure the network), the members of a Hyperledger Fabric network enroll through a trusted Membership Service Provider (MSP). Member organisations would generally set up their own Fabric infrastructure, if they're participating in the blockchain network (context provided earlier). See more on FAQ here -> http://hyperledger-fabric.readthedocs.io/en/release-1.2/Fabric-FAQ.html and understand more on key Fabric Concepts here -> http://hyperledger-fabric.readthedocs.io/en/release-1.2/key_concepts.html . As for Hyperledger Composer, that is a development framework, with tools etc to accelerate development and abstract things to a business level (ie App development using structure/validated, model driven development as a given). See more here -> https://hyperledger.github.io/composer/latest/introduction/introduction (and also see the architectural and key concept links there).
So yes, you will have a running, private blockchain network (including all of the functionality discussed in the docs) with Hyperledger Fabric.
As in Ethereum we can able to create public blockchain and then the user can able to run smart contract on it, same thing we can do in Hyperledger fabric also.
Hyperledger Fabric has the same functionality as smart contracts called as “chaincode”.
A chaincode is a program that is written to read and update the ledger state. All the business logic handled by chaincode.
For example, if a transaction created then chaincode share and update the ledger throughout the network.
About a Fabric based running blockchain we can work on it and can access it but that's only possible when someone from existing network invites you.
It is quite difficult to say you should setup an entire new blockchain network until I know your use case. Based on your use case you can setup an entire new blockchain network using fabric which will be private.
We were planning to build a blockchain based on below logic, but understand due to the private data(a portion of our data is private while some data is public), it is not possible on Ethereum. Would the same design / implementation be possible using Hyperledger Fabric?
Our current design : Blockchain on ethereum but keeping the data related to blocks in some distributed file storage system like IPFS or Storj and storing the hash of data in blocks. But we need our data to be private / shared, so to achieve that we are thinking of using some Key Management Service like NuCypher KMS. But we will have smart contracts on ethereum which can access the data and perform some operations.
We understand that the above logic is unable due to the private nature of data. Is there anyway to establish communication between Hyperledger fabric data and Ethereum smart contract?
It is quite possible to make a part of the transaction data private and other part of the transaction data private in Ethereum using various smart contract obfuscation techniques. One such technique is known as Zero Knowledge Proof which can be implemented in Ethereum at a Smart Contract level using Aztech Protocol. It is possible to implement Zero Knowledge Proofs in Ethereum in a further extended way using ZoKrates libraries which implements libsnarks. In Hyperledger Fabric, from version 1.2 onwards there is a feature known as 'Side DB' which helps us to have private transaction between two peers.
As you have mentioned, using NuCypher platform with homomorphic encryption and proxy re-encryption is always a good idea. We may need to push data from NuCypher into a Smart Contract through Web3.js or by some other easier approach.
With regard to your third question, yes, it is possible to integrated Ethereum and Hyperledger Fabric from Hyperledger 1.4 easily. It has integrated Hyperledger Burrow which makes compiling and deploying Ethereum Smart Contracts on Hyperledger Fabric easier. However I am not sure how much it will help your purpose.
Thinking again, I believe offline encryption using NuCypher / Decentralised Oracles and then invoking Smart Contracts with Meta Data from encrypted data vault looks like a good design choice. I feel Hyperledger Fabric may be an overkill for implementing an offline encryption vault.
Hyperledger offers etereum support. Please look for Seth, Burrow etc. May be that can be your lead.
When I was tasting the fabric, I found many other blockchain projects, like Composer, Cello, Explorer. They are all belong to Hyperledger. I'm very confused that there are so many projects. Should I learn all of them? It seems each project plays a role in the blockchain. BUT:
What's the relation between them?
I draw a picture to explain my question. The picture is not correct, I just want to make my question clear.
If I figure it out, when we want to use the blockchain in our project, I can just study few of them, and use them appropriately.
Fabric provides a framework to set up a blockchain network. It is data/application agnostic.
Composer provides a set of tools to define a business network on top of Fabric. This provides a higher level of abstraction than Fabric where the data are essentially just bits. With Composer you can define assets, transactions, etc.
Cello helps with provisioning of the network.
Explorer simply provides a web based interface to explore what's on a blockchain.
Fabric is a permissioned blockchain distributed ledger, it is at the end; an implementation of a permissioned blockchain.
Hyperledger project comprises a suite of tools for building blockchain business networks, what they name it "Hyperledger Composer".
it is used for developing,testing, deploying application on blockchain
also it is used for integrating your blockchain with external systems,
Cello, is a blockchain provision and operation system, which helps manage blockchain networks, and make the blockchain as service BaaS, it is not a blockchain, but it is used to manage the blockchain network.
Check this link for better understanding Cello
Hyperledger Cello
Explorer provide you KPI that show the blockchain
Cello is admin tool that help you to monitor the host and network with and container inside it, actually cello using fabric script if you take around in fabric you will find byfn (build your first network) script that setup container and example peer.
so cello uses this script to create container and show to you status of this and delete it or edit.
composer provide a tools to help you create your business card and your smart contract to write your smart contract you need to write acl(access control language which define rule),your logic , define participant and assets.
then composer will create bna archive file and install it on blockchain.
there is some module in composer like playground and restserver and also there is generator for frontend
fabric is the framework that setup the blockchain network, it's the base that cello and other module uses it
i hope i help you
I am looking for a way to integrate the IOT with Blockchain. I need to record the device data (IOT device) into the blockchain. I am successfully able to send data from the device to the IOT Hub.How can I record this data in a block chain created using Azure Ethereum Consortium?
Blockchain and IoT are a marriage made in heaven. Blockchain can enable and augment a variety of application scenarios and usecases for the IoT. No longer are such possibilities too futuristic – as we will discuss in this post.
IoT Meets Blockchain...
Blockchain and Internet Of Things (IoT) are easily the two biggest buzzwords in technology at the moment. The IoT encompasses the world of sensors,moving objects like vehicles and really any device that has embedded electronics to communicate with the outside world – typically over an IP protocol.
Combine that with Blockchain – a distributed ledger architecture (DLT) pattern. Combining the two can facilitate the entire lifecycle of IoT devices and applications and prove to be the glue for business processes to act on these events. Consider the following scenario – a private blockchain for a driverless connected car that will enable secure and realtime interactions from the car starting with car startup, driver authentication, smart contracts to exchange insurance and maintenance service information and realtime location info to track safety.
You can learn more about IBM BlockChain and develop your own BlockChain # https://www.ibm.com/developerworks/cloud/library/cl-ibm-blockchain-101-quick-start-guide-for-developers-bluemix-trs/index.html