IEEE Consumer Electronics Magazine - March 2018 - 20

transaction owner digitally signs it by
repeatedly hashing the public key for
source authentication and then broad-
casting the transaction for verifica-
tion by other nodes.
▼▼ Consensus: Because the blockchain
completely revolves around decen-
tralization, there is no trusted third
party responsible for secure storage
and management of data or account-
ability in case of any security breach-
es. All participants collect these
transactions into a new block and
start working on the consensus pro-
tocol to identify the validation of the
transaction. If the consensus is based
on proof of work, then each partici-
pant starts finding the one that is
appropriate.
▼▼ Proof of work: It is the value searched
from a pool of values making the
cryptographic hash value of the
block begin with N number of zeros.
This is to render greater security plus
an opportunity to win some reward
points, thus providing an incentive
for a participant to perform this
proof-of-work calculation.

The building blocks of a
blockchain-based system
include the network participants, a consensus protocol, such as proof of work,
cryptographic hashes, and
digital signatures.
Cryptographic hashes: When a proof
of work is found by a participant, the
block is broadcast to all participants,
who accept it by adding to their
blockchain after computing a crypto-
graphic hash, such as SHA-256 for
the block, to be used as the Hash_
Previous for the next block (Fig -
ure 3). The longest chain is the trusted
one and added to the blockchain
when participants receive multiple
blocks simultaneously.
With the preceding intrinsic fea-
tures acting as an integral part of the
blockchain's operation, it promises
data immutability, data integrity, data

authentication and validation, decen-
tralization, and data transparency, thus
guaranteeing data security across dis-
tributed systems. The blockchain is
immutable. The records can be altered
only if more than 51% of the nodes are
under the control of hackers, which is
unsustainable. The technology is auton-
omous, and it maintains the anonymity
of the sender and receiver in the trans-
action by using public and private keys
of the nodes.

▼▼

APPLICATIONS OF THE
BLOCKCHAIN
The promising features of blockchain
technology are enticing to multiple
industries, but it is important to analyze
the suitability of blockchains with
regard to the needs of each industry. It
is a revolution but not a panacea for all
business needs. Only if the following
situations arise can organizations con-
sider deploying a blockchain-oriented
security solution.
1) A group of people or multiple par-
ties frequently generate transactions
dependent upon a third party.

Blockchain Applications

Smart
Property

Finance
Services

IoT

Asset
Management

Money
Lending

Smart
Appliances

Insurance
Claims
Processing

Smart
Car

SupplyChain
Sensors

Smartphone

Cross-Border
Payments

^

March 2018

Smart
Government

Personal
Health Record
Keeping

Electronic
Passport

Access Control

Birth, ...
Wedding
Certificates

Health-Care
Management

Insurance
Processing

FIGURE 4. The potential applications of a blockchain.
20 IEEE Consumer Electronics Magazine

Smart
Health Care

Personal
Identification
Smart
Community
Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - March 2018
