Abstract:?With an advent of technical advancements in block
chain, it has posed some remarkable solution to the security and privacy
issues?faced by Internet of things (IOT)?along with taking IOT to next level.
The decentralized platform has played a key role towards
this?development.?Block chain uses peer to peer architecture where the
non-trusting members can connect and interact with each other using complex
computational?algorithms.?This?paper?starts with a brief introduction of
blockchain technology. It further describes the mechanism used in
smart?contracts, basic?foundational concept used in developing decentralized
platform. We have also covered the betterment that has?been?brought?to IOT
using block chain making model economic for the device?owners. Down the line we
focus on one of the top research project on block chain and IOT?called
Autonomous decentralized peer to peer telemetry (ADEPT). The combine model of
blockchain and IOT has open new doors to the modern world where automation and
?Blockchain, ?Internet of things, Decentralization, Smart?contracts, ADEPT.?
IOT system has been facing serious privacy and security issues these days.
Several solutions have been proposed but one of the best
possible solution proposed is adopting a decentralized approach. On
adopting Decentralized approach eliminates trusted third part involvement
resulting immune system to the security threats. “Blockchain uses a secure network over untrusted parties which is
desirable in IOT” 4.
“The Identity of the user is kept hidden it is converted to cryptographic
hash function and stored in the Blockchain.
Blockchain enables trustless network” 3 where unknown
parties can interact with each other, Decentralized architecture also
eliminates the single point of failure making system more robust, i.e. if one
of the node in the ledger becomes nonfunctional the system can still resume its
ongoing tasks unlike centralized systems where if the centralized authority fails
the whole system shuts down. This concept has created a keen interest among
researchers and developers for adopting this concept in
the Internet of things.
A. Block chain: ?
“A blockchain is a collection of distributed database
of?records or any digital events that is been shared with all the
intended?participants” 2. All the transactions?are?verified by the
consensus of participants or the peers connected to the ledger considering the
majority. Hence, ?Blockchains works on trustless network as there is no
involvement of third parties all the transactions?are?approved by complex
computational algorithms carried out by miners.?Each block in the chain carries
a list of a transactions and a?hash to the previous block. The exception to
this is the first block of the?chain (not pictured), called genesis, which is
common to all clients in a?blockchain network and has no?parent
3.?However,?blockchain is not only limited to cryptocurrencies it can also be
thought of as chain of blocks identified by its cryptographic hash. Figure 1
describes a chain of blocks with each block carrying the hash of the previous
block i.e. block n carries hash of n-1 block.
Figure 1: A simple blockchain carrying the
hash of previous block (Source: Blockchains and Smart Contracts for?the
Internet of Things)
can be better understood as a set of nodes (clients) that can be a part of same
blockchain 3. Each node interacts with each other using asymmetric
encryption i.e. it used a pair of public and private keys to sign all the
transaction initiated by them. The neighboring peers validated the transaction
using cryptographic hash functions. Upon validating the transaction is added to
the blockchain and a copy of updated ledger is sent to all the peers who are
the part of the ledger.
B. Smart Contracts:
Introduced by Nick
Szabo in 1994 “a computerized transaction
protocol that executes the term of Contract” 3. Smart contracts can
be considered as scripts stored on a blockchain. Smart contracts
can be triggered by addressing a transaction 3. Smart
contracts are not only limited to cryptocurrencies it can
also extend its use to general purpose computing which includes
data driven interactions. Following example supports the
statement. Let’s consider a smart contract consisting
of three people Bob, Alice and Carol defined by Bob. It has two digital
assets asset X and asset Y. Bob defines/deploys three functions 1)
Deposit 2) Trade 3) Withdraw. Deposit function allows bob to deposit
assets to smart contract whit hid own key, trade function sends back a specific
amount of function of Y for every X, withdraw function permits Bob to withdraw
all the assets once his identity is proven.
Bob calls deposit function and deposit 3 units of X
triggers the smart contract. Alice who owns 12 units of Y Calls Trade
function and trades 10 units of Y and gets back 2 units of X. Note both the
transactions are recorded in the blockchain upon approval. Then Bob calls
withdraw function and gets back 10 units of y and 1 unit of X the
contract ensures to verify Bob’s Signature.
III) Autonomous Decentralized Peer to Peer Telemetry
is one of the top ongoing research which collaborates blockchain technology and
IOT together forming a decentralized model. This project is carried out by two
tech-giants IBM in collaboration with Samsung. The primary purpose of this
project is to develop Proof of concept (POC) for decentralized platform. ADEPT
put forward four cases using functional Samsung products. i) AW9000 Samsung
washer autonomous reordering detergent (B2C) ii) W9000 reorder service parts
(B2C) iii) W9000 negotiate power consumption (B2C) iv) display advertisement.
This concept is not just limited to washer, it can be thought of using the same
concept for huge Industrial machines. This can be thought of as the first step
to enter the semi-automatic world where machines can interact with each other
and provide the most economic solutions may it be reordering detergent at the
best price to investing large parts of industrial machinery. Several sensors
which monitors the system performance can get most recent software updated. Any
abnormality in the machine can be detected and the machine can call for the
service by itself. Thus, above project opens a new horizon to automation.
Before diving into detail process several foundational concepts need to be
understood to have a better understanding. Before diving deeper into the few foundational
concepts which are used to build this project are discussed first.
A) Three foundational functions:
achieve decentralized network in IOT three main foundational function must be
of central importance to support the decentralized network. i) Peer-to -peer
messaging ii) Distributed file sharing iii) Autonomous device
Figure 2: Three foundational functions
(Source: Empowering the edge: Practical insights on a decentralized Internet of
Figure 2 describes the
overview of all the functions used in the same network. All the foundational
functions are discussed in detail in the upcoming topics.
i) Peer -to-peer
messaging: Peer-to peer messaging provides an excellent platform for
distributed computing. This kind of architecture provides robustness, as peers
allows us to share resources and data and eliminates the dependency on the
central cloud server. “Peer-to-peer
messaging in a decentralized IoT must support: trustless, encrypted messaging
and transport; low latency with guaranteed delivery; and storage and forwarding
of messages with “hop-on” to other connected devices”. 6. Distributes
Hash Tables (DTH) helps fulfilling such needs, enables peers to find for other
peers on the network using the table created known as “hash table”. Each peer
is assigned a public key and identity is stored in the hash table. Message are
exchanged using this key. As far as ADEPT is concerned it uses “TELEHASH” for
peer-to-peer messaging. Telehash-A light weight protocol with strong encryption
enabling mesh networks.
ii) Distributed file
sharing: Enables file sharing of large orders. Consider a network of say n
peers here peers are some large automated industrial machines. If there is a
software update in the system so this software update is being shared in the
distributed peers using distributed file sharing. ADEPT uses Bit torrent for
this purpose. Bit torrent: “BitTorrent is
a communication protocol for peer-to-peer file sharing (“P2P”) which
is used to distribute data and electronic files over the Internet.” 7. the
above-mentioned file sharing is achieved using DTH.
iii) Autonomous Device
coordination: Autonomous device coordinates provides higher privileges to the
device owner than as third-party roles are not into picture. Three main
functions are defined simple device coordination where registration and
authentication are being taken care of. More complex interactions where owner
of the device defines a system under a specific set of rules. Another type include
device coordination is contracts this involves payments and other procedures.
ADPET has used “Ethereum” for the device coordination. Figure 3 shows the
autonomous device framework. Ethereum: “Ethereum
is a decentralized platform that runs smart contracts: applications that run
exactly as programmed without any possibility of downtime, censorship, and
fraud or third-party interference”. 1