Blockchain Technology
                     BLOCKCHAIN TECHNOLOGY
Introduction
Blockchain technology is most simply defined as 
a decentralized, distributed ledger that records 
the provenance of a digital asset. 
By inherent design, the data on a blockchain is 
unable to be modified, which makes it a 
legitimate disruptor for industries like payments, 
cybersecurity and healthcare.
Source: builtin.com
What is 
Blockchain?
Blockchain, sometimes referred to as Distributed 
Ledger Technology (DLT), makes the history of 
any digital asset unalterable and transparent 
through the use of decentralization and 
cryptographic hashing. 
Source: builtin.com
How Does 
Blockchain Work?
Blockchain consists of three important concepts: 
blocks, nodes and miners.
Every chain consists of multiple blocks and each 
block has three basic elements.
Source: builtin.com
Blocks
• Every chain consists of multiple blocks and 
each block has three basic elements:
• The data in the block.
• A 32-bit whole number called a nonce. The nonce is 
randomly generated when a block is created, which 
then generates a block header hash. 
• The hash is a 256-bit number wedded to the nonce. It 
must start with a huge number of zeroes (i.e., be 
extremely small).
Source: builtin.com
Miners
• Miners create new blocks on the chain through 
a process called mining.
• In a blockchain every block has its own unique 
nonce and hash, but also references the hash 
of the previous block in the chain, so mining a 
block isn't easy, especially on large chains.
Source: builtin.com
Nodes
• One of the most important concepts in 
blockchain technology is decentralization. No 
one computer or organization can own the 
chain. 
• Instead, it is a distributed ledger via the nodes 
connected to the chain. Nodes can be any kind 
of electronic device that maintains copies of 
the blockchain and keeps the network 
functioning. 
Source: builtin.com
Why blockchain 
is important?
• Blockchain is ideal for delivering that 
information because it provides immediate, 
shared and completely transparent information 
stored on an immutable ledger that can be 
accessed only by permissioned network 
members. 
Source: www.ibm.com
Key elements of a blockchain
Distributed 
ledger 
technology
• All network participants have access to the 
distributed ledger and its immutable record of 
transactions. 
• With this shared ledger, transactions are 
recorded only once, eliminating the duplication 
of effort that’s typical of traditional business 
networks.
Source: www.ibm.com
Immutable 
records
• No participant can change or tamper with a 
transaction after it’s been recorded to the 
shared ledger. 
• If a transaction record includes an error, a new 
transaction must be added to reverse the 
error, and both transactions are then visible.
Source: www.ibm.com
Smart contracts
• To speed transactions, a set of rules — called a 
smart contract is stored on the blockchain and 
executed automatically. 
• A smart contract can define conditions for 
corporate bond transfers, include terms for 
travel insurance to be paid and much more.
Source: www.ibm.com