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Sign and verify Signature with Solidity and Javascript

Tutorial about signing and validating data in solidity and javascript.

Creating and validating signatures is crucial part in many transactions and applications.

In this tutorial the signature is created in javascript utilizing the libraries eth-crypto, web3 and ganache-cli.

The javascript library EthCrypto ist responsible for signing the message (for example with a keccak256).

The validation takes place in a smart contract (Solidity).

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Validating a signature in Solidity.

Validating a  signature in Solidity. This smart contract written in Solidity shows how to validate a signature passed to a function.

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How to create your own ethereum fork

This stackexchange thread explains how to induce a fork in a private Ethereum testnet. The solution is to block the network ports. It also shows the test details.

Creating forks in a Ethereum blockchain can be useful for testing different behaviors.

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How to fork Ethereum testnet

Question raised how to create a fork on a private Ethereum testnet.

Unfortunately without satisfying answer.

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Antonopoulos talking about the Internet of Money

Video showing Andreas Antonopoulos in Chicago talking about the years 2013 – 2018. He reflects the development in price and attention the blockchain technology received. And he predicts a bright future for this technology.

The essence of his talk is that the incredible price hike between mid-2017 and end of 2017 distracted many people from making progress in the technological development of the blockchain technologies. And now is the time to make progress in improving the user experience and the manageability of the underlying technology. As Antonopoulos said put it, it is time to plant the seed for the future, since we are right at the beginning.

He encourages startups and individuals alike to contribute and offer support to the community.

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Ganache – a truffle framework

Ganache is a local blockchain setup for coding, testing and developing Ethereum smart contracts.

Ganache offers you several accounts which who you can interact with your smart contract. The accounts have a certain amount of Ether and an address. It helps you to inspect the state while firing transactions and calling functions of your smart contract.

There is no local Ethereum client necessary which makes the setup faster and more stable.

The website features also some tutorials that help you to set up Ganache and use it in your production.

Ganache is part of truffle.

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Connecting Angular and Ethereum to build a dApp

This resource describes how to build dApps (decentralised apps) using Angular and Ethereum.

The tutorial walks us step by step towards creating an dApp.

In order to do so it utilizes tools and librariey like Truffle, web3, Ganache, nodejs and of cource angular, which need to be installed on your computer. Links to tutorials are provided.

Angular serves in the show case as UI framework. The autor notifys us that other UI frameworks than Angular and blockchain solutions can be tied together.

Ganache – a truffle framework

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List of Angular resources

Comprehensive list of resources for coding and development with Angular.

  • IDEs
  • Tools
  • Books
  • Libraries
  • UI Components
  • Workshops and Trainings

Connecting Angular and Ethereum to build a dApp

Tutorial on how to create an Ethereum dApp and Angular as backend.
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Position Paper on Blockchain, GDPR and Dataprotection

In this position paper Bundesblock criticizes that the GDPR does not take blockchain into consideration. I provides recommendations on how to treat blockchain with respect to the GDPR.

The pdf outlines briefly which data fall under the GDPR and what private data is.

It also explains what Data are storedy and used typically in a blockchain and that those data are stored permanently.

According to the position paper the GDPR is a threat to blockchain initiatives in Europe and Germany. Particularly Miner and Nodes might be liable for storing sensitive information.

The paper makes statements about Principles in handling data, the right to e, the right to restrict processing and the right to port personal data.

 

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Proxy Libraries for Ethereum Smart Contracts

This article describes a proxy library approach. It allows for updateable Solidity (ethereum) smart contracts.