Science & Technology
Blockchain
Distributed data store for digital transactions
Overview
A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data. Since each block contains information about the previous block, they effectively form a chain, with each additional block linking to the ones before it. Consequently, blockchain transactions are resistant to alteration because, once recorded, the data in any given block cannot be changed retroactively without altering all subsequent blocks and obtaining network consensus to accept these changes.
Source: Wikipedia — Blockchain (CC BY-SA)
Key concepts
How Blockchain connects to the ideas, people and events around it.
A distributed ledger is a system whereby replicated, shared, and synchronized digital data is geographically spread (distributed) across many sites, countries, or institutions.
In computer science, a record is a composite data structure – a collection of fields, possibly of different data types, typically fixed in number and sequence.
A cryptographic hash function (CHF) is a hash algorithm that has special properties desirable for cryptographic applications.
Trusted timestamping is the process of securely keeping track of the creation and modification time of a document.
In cryptography and computer science, a hash tree or Merkle tree is a tree in which every "leaf" node is labelled with the cryptographic hash of a data block, and every node that is not a leaf is labelled with the cryptographic hash of the labels of its child nodes.
A node is a basic unit of a data structure, such as a linked list or tree data structure. Nodes contain data and also may link to other nodes. Links between nodes are often implemented by pointers.
In computer science, a linked list is a linear collection of data elements whose order is not given by their physical placement in memory. Instead, each element points to the next.
Peer-to-peer (P2P) computing or networking is a distributed computing or networking architecture in which participants share part of their own resources, such as processing power, storage, or network capacity.
Revise Blockchain
Flashcards and a quick quiz, built from this map.
Questions about Blockchain
What is Blockchain?
A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data. Since each block contains information about the previous block, they effectively form a chain, with each additional block linking to the ones before it.
What are the key concepts related to Blockchain?
The main concepts connected to Blockchain include Distributed ledger, Record (computer science), Cryptographic hash function, Trusted timestamping, Merkle tree, Node (computer science), Linked list, Peer-to-peer. Each is linked on the map above with its own summary.
Which exams cover Blockchain?
Blockchain is part of Science & Technology, which appears in the syllabus of UPSC CSE, UPSC CAPF, NDA, CDS, AFCAT, RRB NTPC and 32 more exams.