Blockchain | simple words , Blockchain can be defined as a chain | Blockchain library

 by   nik9hil Python Version: Current License: MIT

kandi X-RAY | Blockchain Summary

kandi X-RAY | Blockchain Summary

Blockchain is a Python library typically used in Blockchain, Ethereum, Bitcoin applications. Blockchain has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. However Blockchain build file is not available. You can download it from GitHub.

WHAT IS BLOCKCHAIN? In simple words, Blockchain can be defined as a chain of the block that contains information. The technique is intended to timestamp digital documents so that it's not possible to backdate them or temper them. The blockchain is used for the secure transfer of items like money, property, contracts, etc. without requiring a third-party intermediary like bank or government. Once a data is recorded inside a blockchain, it is very difficult to change it. The blockchain is a software protocol (like SMTP is for email). However, Blockchains could not be run without the Internet. It is also called meta-technology as it affects other technologies. It is comprised of several pieces: a database, software application, some connected computers, etc. BLOCKCHAIN ARCHITECTURE A Blockchain is a chain of blocks which contain information. The data which is stored inside a block depends on the type of blockchain. For Example, A Bitcoin Block contains information about the Sender, Receiver, number of bitcoins to be transferred. The first block in the chain is called the Genesis block. Each new block in the chain is linked to the previous block. WHAT MAKES BC SO SPECIAL? A block also has a hash. It can be understood as a fingerprint which is unique to each block. It identifies a block and all of its contents, and it's always unique, just like a fingerprint. So once a block is created, any change inside the block will cause the hash to change. Therefore, the hash is very useful when you want to detect changes to intersections. If the fingerprint of a block changes, it does not remain the same block. Each Block has Data Hash Hash of the previous block Consider following example, where we have a chain of 3 blocks. The 1st block has no predecessor. Hence, it does not contain the previous block. Block 2 contains a hash of block 1. While block 3 contains Hash of block 2. Hence, all blocks are containing hashes of previous blocks. This is the technique that makes a blockchain so secure. Let's see how it works - Assume an attacker is able to change the data present in the Block 2. Correspondingly, the Hash of the Block also changes. But, Block 3 still contains the old Hash of the Block 2. This makes Block 3, and all succeeding blocks invalid as they do not have correct hash the previous block. Therefore, changing a single block can quickly make all following blocks invalid. The blockchain is designed in a way such that the average time for a block to be generated remains fairly constant. In the bitcoin blockchain, the average time for a block to generate is 10 minutes. Other blockchains may have a different time, e.g. 30 seconds, 5 minutes, etc. The controlled block generation time is achieved by adding a difficulty value inside the block. In bitcoin, the hash of the block must be strictly smaller than a given value to be accepted. The given value varies according to the total computation power of the network. The more powerful the network is, the more smaller the given value, and hence the more difficult it is to generate the block. Contributors: Nikhil Bhardwaj- @nik9hil Darshan Chheda- @darshanc99 Rohit Gupta- @rohiiit Raj Doshi- @Rajdoshi99.
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            kandi-support Support

              Blockchain has a low active ecosystem.
              It has 2 star(s) with 2 fork(s). There are no watchers for this library.
              OutlinedDot
              It had no major release in the last 6 months.
              Blockchain has no issues reported. There are no pull requests.
              It has a neutral sentiment in the developer community.
              The latest version of Blockchain is current.

            kandi-Quality Quality

              Blockchain has 0 bugs and 0 code smells.

            kandi-Security Security

              Blockchain has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              Blockchain code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              Blockchain is licensed under the MIT License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              Blockchain releases are not available. You will need to build from source code and install.
              Blockchain has no build file. You will be need to create the build yourself to build the component from source.
              It has 51 lines of code, 5 functions and 1 files.
              It has low code complexity. Code complexity directly impacts maintainability of the code.

            Top functions reviewed by kandi - BETA

            kandi has reviewed Blockchain and discovered the below as its top functions. This is intended to give you an instant insight into Blockchain implemented functionality, and help decide if they suit your requirements.
            • Compute the SHA - 256 hash of the block .
            • Adds a new block to the blockchain .
            • Mine the given block into the chain .
            • Return a string representation of the block .
            • Initialize data .
            Get all kandi verified functions for this library.

            Blockchain Key Features

            No Key Features are available at this moment for Blockchain.

            Blockchain Examples and Code Snippets

            No Code Snippets are available at this moment for Blockchain.

            Community Discussions

            QUESTION

            Why Metamask if web3.js can interact directly with ganache?
            Asked 2022-Mar-30 at 17:55

            I am new to blockchain app development, I saw a project where ganache accounts are imported into Metamask, then web3.js is used to access and print those accounts and balances on Frontend (user interface).

            If web3.js can directly access ganache blockchain accounts and balances, why do we need Metamask in between?

            ...

            ANSWER

            Answered 2022-Feb-08 at 09:11

            If web3.js can directly acccess ganache blockchain accounts and balances, why we need metamask in between?

            In this case, you don't need MetaMask to sign the transaction, as the node (Ganache) holds your private key.

            But in a public environment (testnets and mainnet), the node doesn't hold your private key, so you'd need to sign the transaction using MetaMask (or any other tool that holds the private key).

            Source https://stackoverflow.com/questions/70952165

            QUESTION

            Error: Property 'body' cannot be accessed on 'Response?' because it is potentially null
            Asked 2022-Mar-29 at 00:29

            so I'am trying to learn dart and flutter and everything went well so far. But now I'am stuck at an error which I cannot handle. I coded a function which is supposed to asynchronously return the actual BTC price from https://blockchain.info/ticker.

            Only thing it returns is errors:

            ...

            ANSWER

            Answered 2022-Mar-29 at 00:29

            To get rid of that error you need to use the bang operator to tell the compiler that snapshot.data won't be null.

            Source https://stackoverflow.com/questions/71640944

            QUESTION

            How to send a web3 transaction from a test account of RSKj regtest blockchain node
            Asked 2022-Mar-25 at 10:34

            I am creating a DApp that connects to a smart contract deployed on a local test RSK blockchain (regtest) run by RSKj Java app. I intend to send transactions via Web3 connected to Metamask. In DApp I am getting the accounts list by sending a Web3 request:

            ...

            ANSWER

            Answered 2022-Mar-25 at 10:34

            The first account from the list is referred as a “cow” seed in this file in RSKj. You can take the corresponding private key from there.

            Do the following:

            1. copy the private key c85ef7d79691fe79573b1a7064c19c1a9819ebdbd1faaab1a8ec92344438aaf4,
            2. open your Metamask browser plugin
            3. select regtest network
            4. import the account
              1. Account icon in the upper right corner
              2. Import account
              3. ‘Paste your private key string here:’
            5. Set the just imported account as an active one
            6. Enjoy sending your transactions

            Source https://stackoverflow.com/questions/69450433

            QUESTION

            How can I convert an [u8] hex ascii representation to a u64
            Asked 2022-Mar-17 at 10:57

            I would like to convert my bytes array into a u64.

            For example b"00" should return 0u64 b"0a" should return 10u64

            I am working on blockchain, so I must find something efficient.
            For example, my current function is not efficient at all.

            ...

            ANSWER

            Answered 2022-Mar-16 at 20:21

            QUESTION

            The transaction declared chain ID 5777, but the connected node is on 1337
            Asked 2022-Mar-11 at 02:52

            I am trying to deploy my SimpleStorage.sol contract to a ganache local chain by making a transaction using python. It seems to have trouble connecting to the chain.

            ...

            ANSWER

            Answered 2022-Jan-17 at 18:17

            Had this issue myself, apparently it's some sort of Ganache CLI error but the simplest fix I could find was to change the network id in Ganache through settings>server to 1337. It restarts the session so you'd then need to change the address and private key variable.

            If it's the same tutorial I'm doing, you're likely to come unstuck after this... the code for transaction should be:

            Source https://stackoverflow.com/questions/70731492

            QUESTION

            How to locally unit-test Chainlink's Verifiable Random Function?
            Asked 2022-Mar-08 at 04:12
            Context

            While trying to set up a basic self-hosted unit testing environment (and CI) that tests this Chainlink VRF random number contract, I am experiencing slight difficulties in how to simulate any relevant blockchains/testnets locally.

            For example, I found this repository that tests Chainlinks VRF. However, for default deployment it suggests/requires a free KOVAN_RPC_URL e.g. from Infura's site and even for "local deployment" it suggests/requires a free MAINNET_RPC_URL from e.g. Alchemy's site.

            Attempt/baseline

            I adopted a unit test environment from the waffle framework which is described as:

            Filestructure ...

            ANSWER

            Answered 2021-Sep-09 at 04:35

            to test locally you need to make use of mocks which can simulate having an oracle network. Because you're working locally, a Chainlink node doesn't know about your local blockchain, so you can't actually do proper VRF requests. Note you can try deploy a local Chainlink node and a local blockchain and have them talk, but it isn't fully supported yet so you may get mixed results. Anyway, as per the hardhat starter kit that you linked, you can set the defaultNetwork to be 'hardhat' in the hardhat.config.js file, then when you deploy and run the integration tests (yarn test-integration), it will use mocks to mock up the VRF node, and to test the requesting of a random number. See the test here, and the mock contracts and linktoken get deployed here

            Source https://stackoverflow.com/questions/69089799

            QUESTION

            I want to get the address from mnemonic with the proper derivation path
            Asked 2022-Feb-23 at 00:41

            I am very new to blockchain programming and programming in general. I want to generate my SOL address using the mnemonic seed phrase with the derivation path "m/44'/501'/0'/0". I can't find a proper BIP44 module for python where you can specify the derivation path.

            ...

            ANSWER

            Answered 2022-Feb-23 at 00:41

            After a long search through the internet, I have finally found a way of solving my problem that I want to share with you.

            Source https://stackoverflow.com/questions/71217530

            QUESTION

            how to sign a message with ecdsa privatekey using golang?
            Asked 2022-Feb-20 at 14:48

            I am trying to sign a message in go generated via hd wallet's private key using cosmos sdk. Below is the equivalent implementation in python which generates the signed message / signature as expected when submitted/verified is working properly but unable to get it working wtih Go implementation. Any inputs for equivalent golang version of the python implementation is much appreciated. Thank you.

            Python version uses sha256 , ecdsa but when using the equivalent cyrpto/ecdsa doesn't return valid signature.

            Python

            ...

            ANSWER

            Answered 2022-Feb-20 at 14:48

            Both codes return hex encoded as private key

            Source https://stackoverflow.com/questions/71186925

            QUESTION

            Flag provided but not defined: -rpc
            Asked 2022-Feb-19 at 20:07

            Am starting off in blockchain development using the book Mastering Blockchain - A deep dive into distributed ledgers, consensus protocols, smart contracts, DApps, cryptocurrencies, Ethereum,

            Am using WSL with geth version 1.10.9.

            ...

            ANSWER

            Answered 2021-Oct-11 at 23:20

            It appears 1.10.9-stable version has a problem and is returning a -rpc error. GETH 1.10.8-stable version works fine when running the geth command with --rpc

            Source https://stackoverflow.com/questions/69463898

            QUESTION

            ParserError: Source file requires different compiler version
            Asked 2022-Feb-08 at 13:18

            I tried all that you mentioned in the discussion here (in other questions) and at https://github.com/smartcontractkit/full-blockchain-solidity-course-py/discussions/522 , however it is not solving the issue for me, I also noticed that the current compiler version remains (current compiler is 0.6.12+commit.27d51765.Windows.msvc). But when I right click and select Solidty:Compiler information, it shows 0.8.0.

            from output:

            ...

            ANSWER

            Answered 2022-Jan-02 at 03:09

            i had the same issue. i had this compiler setting:

            Source https://stackoverflow.com/questions/70459922

            Community Discussions, Code Snippets contain sources that include Stack Exchange Network

            Vulnerabilities

            No vulnerabilities reported

            Install Blockchain

            You can download it from GitHub.
            You can use Blockchain like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.

            Support

            For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .
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