Correct Answer :   A distributed ledger on a peer to peer network

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Explanation : A Blockchain is a constantly growing ledger(file) that keeps a permanent record of all the transactions that have taken place, in a secure, chronological, and immutable way. It can be used for the secure transfer of money, property, contracts, etc. without requiring a third-party intermediary like bank or government.

Correct Answer :   David Chaum

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Explanation : Cryptographer David Chaum first proposed a blockchain-like protocol in his 1982 dissertation "Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups.

Correct Answer :   2008

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Explanation : The blockchain was popularized by a person (or group of people) using the name Satoshi Nakamoto in 2008 to serve as the public transaction ledger of the cryptocurrency bitcoin, based on work by Stuart Haber, W. Scott Stornetta, and Dave Bayer. The identity of Satoshi Nakamoto remains unknown to date. The implementation of the blockchain within bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server. 

Correct Answer :   Wallet

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Explanation : Just the way we keep cash or cards in a physical wallet, bitcoins are also stored in a wallet—a digital wallet. The digital wallet can be hardware-based or web-based. The wallet can also reside on a mobile device, on a computer desktop, or kept safe by printing the private keys and addresses used for access on paper.

Correct Answer :   New York

Correct Answer :   Decentralized

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Explanation : Blockchain is a peer-to-peer decentralized distributed ledger technology that makes the records of any digital asset transparent and unchangeable and works without involving any third-party intermediary.

Correct Answer :   Peer to Peer

Correct Answer :   A computer on a Blockchain network

Correct Answer :   Satoshi Nakamoto

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Explanation : Satoshi Nakamoto is the pseudonym who penned the original Bitcoin whitepaper and is the identity credited with inventing Bitcoin itself.

Correct Answer :   All of the above statements are true

Correct Answer :   merkle tree

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Explanation : Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree.

Correct Answer :   Database

Correct Answer :   On an exchange

Correct Answer :   Unspent Transaction Output

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Explanation : An Unspent Transaction Output (UTXO) is the technical term for the amount of digital currency that remains after a cryptocurrency transaction.

Correct Answer :   Ralph Merkle

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Explanation : Merkle trees were invented by Ralph Merkle in 1988 in an attempt to construct better digital signatures. You can read Merkle's original paper or you can read this easier paper.

Correct Answer :   Silk Road

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Explanation : Silk Road 2.0 shut down by FBI and Europol on 6 November 2014. In October 2013, the Federal Bureau of Investigation (FBI) shut down the website and arrested Ross Ulbricht under charges of being the site's pseudonymous founder "Dread Pirate Roberts".

Correct Answer :   All of the Above

Correct Answer :   A fork

Correct Answer :   Easier to scale

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Explanation : In comparison to a standard centralized network, a decentralized network has several advantages, including greater system reliability and privacy. Furthermore, such networks are far easier to grow and have no single point of failure.

Correct Answer :   Computers that validate and process blockchain transactions

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Explanation : Miner is an actor who participates in cryptocurrency transactions, and in turn, plays a crucial role both in creating new cryptocurrencies and in verifying transactions on the blockchain. It adds new blocks to the existing chain, and ensures that these additions are accurate.

Correct Answer :   Takes an input of any length and returns a fixed-length string of numbers and letters

Correct Answer :   False

Correct Answer :   Without involving any third party

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Explanation : A shared ledger, or blockchain, is a system that allows thousands of computers or servers to maintain a single, secure, and immutable record. Without the necessity of third-party intermediaries, blockchain may conduct user transactions. All that is required to conduct transactions is the possession of a wallet.

Correct Answer :   3

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Explanation : Blockchain has three versions.
Blockchain 1.0 : Cryptocurrency.
Blockchain 2.0 : Smart Contracts.
Blockchain 3.0 : DApps.

Source : F T L

Correct Answer :   Header & Transaction

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Explanation : The block is made up of a metadata-filled header and a long list of transactions that make up the majority of its size. The typical transaction is at least 250 bytes long, while the average block comprises more than 500 transactions.

Correct Answer :   All of the Above

Correct Answer :   All of the Above

Correct Answer :   The first block of a Blockchain

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Explanation : Since every bitcoin traces its genealogy back to the Genesis Block, also known as Block 0, every other bitcoin block may trace its lineage back to it.

Correct Answer :   Mt. Gox

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Explanation : Mt. Gox. Gox was a bitcoin exchange based in Shibuya, Tokyo, Japan. Launched in July 2010, by 2013 and into 2014 it was handling over 70% of all bitcoin (BTC) transactions worldwide, as the largest bitcoin intermediary and the world's leading bitcoin exchange.

Correct Answer :   All of the above

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Explanation : “Each block contains a hash (a digital fingerprint or unique identifier), timestamped batches of recent valid transactions, and the hash of the previous block. The previous block hash links the blocks together and prevents any block from being altered or a block being inserted between two existing blocks.” In theory, the method renders the blockchain tamperproof.

Correct Answer :   Ethereum full node

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Explanation : Ethereum is a distributed network of computers (known as nodes) that can validate blocks and transaction data by executing software. To "run" a node on your computer, you'll need a client application.

Correct Answer :   All of the above

Correct Answer :   Mining

Correct Answer :   InterPlanetary File System

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Explanation : The InterPlanetary File System (IPFS) is a protocol and peer-to-peer network for storing and sharing data in a distributed file system. IPFS uses content-addressing to uniquely identify each file in a global namespace connecting all computing devices.

Correct Answer :   A decentralized application

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Explanation : Key Takeaways. Decentralized applications—also known as "dApps" or "dapps"—are digital applications that run on a blockchain network of computers instead of relying on a single computer. Because dApps are decentralized, they are free from the control and interference of a single authority.

Correct Answer :   Prevents double spending

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Explanation : A nonce is an abbreviation for "number only used once," which is a number added to a hashed—or encrypted—block in a blockchain that, when rehashed, meets the difficulty level restrictions. The nonce is the number that blockchain miners are solving for, in order to receive cryptocurrency.

Correct Answer :   A block reward

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Explanation : For incentivizing the Miner for his correct decisions during the transactions, the sender generally sends some incentives (rewards) in form of the cryptocurrency, in which the transaction takes place. It is generally a small percentage of the whole transaction that takes place.

Correct Answer :   A node that provides additional supervisory network services

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Explanation : Masternodes are powerful servers backed by collateral held in Dash, and are designed to provide advanced services and governance on the blockchain. Dash has been associated with the concept of masternodes ever since the invention of this novel concept soon after the project started in 2014.

Correct Answer :   Immutability

Correct Answer :   White Paper

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Explanation : Satoshi Nakamoto is the name used by the presumed pseudonymous person or persons who developed bitcoin, authored the bitcoin white paper, and created and deployed bitcoin's original reference implementation.

Correct Answer :   Any mechanism that allows tokens from one blockchain to be securely used within a completely separate Blockchain

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Explanation : A sidechain is a separate blockchain which runs in parallel to Ethereum Mainnet and operates independently. It has its own consensus algorithm (e.g. proof-of-authority, Delegated proof-of-stake, Byzantine fault tolerance). It is connected to Mainnet by a two-way bridge.

Correct Answer :   Multiple people simultaneously.

Correct Answer :   No – they cannot be altered.

Correct Answer :   None of the Above

Correct Answer :   Public

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Explanation : Public blockchain can be used to construct a completely open blockchain, similar to Bitcoin, that allows everyone and everyone to join and contribute to the network.

Correct Answer :   Bitcoin ATM

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Explanation : A Bitcoin ATM (abbreviated as BATM) is a kiosk where a person can purchase Bitcoin using an automated teller machine.

Correct Answer :   The first block of a Blockchain

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Explanation : A Genesis Block is the name given to the first block a cryptocurrency, such as Bitcoin, ever mined. A blockchain consists of a series of so-called blocks that are used to store information related to transactions that occur on a blockchain network.

Correct Answer :   Gas

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Explanation : For every instruction implemented on the Ethereum Virtual Machine(EVM), a system that keeps track of execution cost, assigns to the instruction an associated cost in Gas units.

Correct Answer :   A transaction and block verification protocol

Correct Answer :   21 million

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Explanation : When Satoshi Nakamoto created Bitcoin, he installed a strict limit on the number of Bitcoin that could ever exist. There will never be more than 21 million bitcoin. This limit, known as the hard cap, is encoded in Bitcoin's source code and enforced by nodes on the network.

Correct Answer :   All of the above

Correct Answer :   Alterable

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Explanation : Smart Contracts (SC) are digital code sets designed to make asset transfers easier (including non-digital assets). They are clear, precise, quick, and cost-effective.

Correct Answer :   False

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Explanation : Bitcoin is a digital currency that is secure thanks to Blockchain technology. Ethereum Blockchain Ethereum uses a blockchain network to perform its operations. Ethereum, a public blockchain network, is increasingly being used to facilitate enterprise transactions needing automatic, rule-based asset transfer, just like all cryptocurrencies.

Correct Answer :   True

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Explanation : Symmetric encryption, often known as a secret key algorithm, employs only one key: a secret key for message encryption and decoding. It is simple to deduce the secret key from the encrypted data in the simple symmetric key case described in the lecture.

Correct Answer :   Simple Hash

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Explanation : Masking off the bottom m bits to use as an index into a table of size 2 m is a basic hash function. A folding hash code is created by dividing the input into n pieces of m bits each, where 2m is the table size, then combining the sections with a parity-preserving bitwise operation like ADD or XOR.

Correct Answer :   Tree-structured Hash

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Explanation : In the fields of cryptography and computing science, Hash trees, also known as Merkle trees, are a sort of data structure that stores a tree of summary information about a bigger piece of data, such as a file, and is used to validate its contents. Hash trees are a subset of hash lists, which are themselves subsets of hashing.

Correct Answer :   Mining

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Explanation : The process of creating bitcoin popularly known as Mining.

Correct Answer :   January 2009

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Explanation :

Correct Answer :   Hash of transactions

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Explanation : By hashing together pairs of TXIDs, a Merkle root is generated, which gives you a brief yet unique fingerprint for all the transactions in a block.

Correct Answer :   SHA256

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Explanation : SHA 256 is a member of the SHA 2 algorithm family, with SHA standing for Secure Hash Algorithm. It was a joint effort between the National Security Agency and the National Institute of Standards and Technology to introduce a successor to the SHA 1 family, which was slowly losing power against brute force attacks. It was published in 2001.

Correct Answer :   All of the Above

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Explanation : Cross-border payments, anti-money laundering tracking systems, supply chain and logistics monitoring, and so on are just a few of the possibilities for blockchain.

Correct Answer :   Programs stored on a blockchain that run when predetermined conditions are met

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Explanation : A "smart contract" is software that runs on Ethereum's blockchain. It's a collection of code (its functions) and data (its state) that lives on the Ethereum blockchain at a single address. Ethereum accounts come in the form of smart contracts.

Correct Answer :   There is no central server, it is distributed

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Explanation : There is no central server in a blockchain, which is a digital distributed ledger of transactions that are recorded and duplicated in real-time throughout a network.

Correct Answer :   7-15 per second

Correct Answer :   Mapping between owner and object

Correct Answer :   Requirement identification

Correct Answer :   Number of blocks

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Explanation : The total number of blocks connected since the genesis block is the block height. The number of blocks between any given block and the genesis block determines its height.

Correct Answer :   Fast transaction time

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Explanation : When a blockchain's scalability is high, it means the network can handle a large number of transactions quickly. It enables separate accounts to exchange data swiftly, if not immediately, independent of the network traffic.

Correct Answer :   Genesis

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Explanation : A genesis block (block number 0) is the initial block in a blockchain. This is the sole block in a blockchain that does not include any transactions and does not have a valid reference to a previous block.