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DINRG                                                            H. Ding
Internet-Draft                                                   Z. Jiao
Intended status: Informational                                 Chaincomp
Expires: March 13, 2019                               September 14, 2018

Blockchain-based IoT Infrastructure Functional Requirements


This document specifies the functional requirements for a
Blockchain-based IoT infrastructure, including the IoT device identity
management, service demand and supply matching, support of smart
contract, etc.

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   This Internet-Draft will expire on March 13, 2019.

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Table of Contents
1. Introduction 2
2. Blockchain enabled IoT infrastructure requirements   3
2.1. Identity Management        3
2.2. Service Demand and Supply Matching 4
2.3. Decentralized Service Scheduling   4
2.3.1. Service Matching Policies        4
2.3.2. Consensus Protocols      4
2.4. Smart Contract     5
3. Different Node Types and Functions   5
4. Security Considerations      6
5. IANA Considerations  7
6. Acknowledgments      7

1. Introduction

With IoT devices proliferating in smart homes, smart cities, smart
industries, smart transport, smart health, etc., these devices often
lack security consideration due to constrained resources, hence
vulnerable to hacking which may cause serious problems in businesses,
environment and day-to-day lives. Besides, vendor specific IoT
platforms hinder data exchange among devices, create isolated value
island and hampers the growth of the ecosystem. The emerging Blockchain
technologies, with a decentralized trustless architecture and
incentives for sharing, may be able to resolve the trust, security and
interoperability challenges for IoT.

IoT devices play an important part in businesses growth via digital
transformation, while Blockchain technologies can be adopted
to manage the identities of those devices as the very beginning to
establish trust. Once registered in the immutable decentralized ledger,
admission control can be implemented, potential threats can be detected
and mitigated.

Autonomous coordination among devices via transactions and smart
contracts incentivize data and resource exchange across different
vendor specific IoT devices, thus enables Device-to-Device economy.

2. Blockchain enabled IoT infrastructure requirements

The Blockchain-based IoT infrastructure should support identity
management, service demand and supply matching, smart contract, etc. in
a proper way to realize the value of Internet of Things. A possible
large scale Blockchain-based IoT infrastructure can be a hybrid of
permission-less chain and permissioned chain, and applications can
choose different deployment that suits its business requirements.

2.1. Identity Management
The life span of an IoT device can be several years to decades. The
infrastructure should support identity management which is able able to
register the device on the immutable ledger and authenticate its
identity when necessary during its lifetime.

Once a device is produced, the manufacturer can register an
identifiable ID along with its manufacturing information, such as
warranty, to a permission-less chain so that it can provide maintenance
to customers after products are sold. Besides, the registration on
permission-less public chain allows every one accessIf necessary, such
identity information can also be used in shipping and inventory
management at retailor sites.

After the device is purchased, the user obtains its full ownership
including the data it collects and generates. The device should be able
to generate a pair of public key and private key. The public key is
used to identify a specific device among others, while the private key
is used as proof of identity for future validation on real-time
messaging and transaction.

The owner can register the device on a permissioned chain in order to
perform admission control, so that only authorized devices and
personnel can interact with the device and access its data. After the
registration is completed, the device is able to submit transactions
signed by its private key and the network of peer devices can verify
them, so the history of all data/resource exchange will be recorded and
kept safe for future reference and audition.

2.2. Service Demand and Supply Matching
To fully activate the capabilities of IoT ecosystem, the devices should
have a way to demand and supply services to each other autonomously.

Each device will publish its specific functionalities to the
peer-to-peer network, and other devices in the network can subscribe to
the peers of interest by reading the published functionalities. As the
subscription content grows, the possibility of one device finding a
matching demand and supply service pair would be higher.

When a matching pair is found, the two devices will become two parties
in a smart contract, trading service with associated fees without the
need of a third party. The system can implement a number of service
scheduling policies to optimize the matching process.

2.3 Decentralized Service Scheduling
There can be different service scheduling policies in the autonomous
coordination among IoT devices, for example, service matching policies,
and the consensus protocols.

2.3.1 Service Matching Policies
As introduced in Section 2.2, peer nodes should coordinate autonomously
in service exchange. Some service matching policies may be more
suitable than others in different scenarios meaning that a certain
policy would make a match sooner or more effective.

For example, a device adopting the latest publish first policy will
choose the latest published services on Blockchain because the service
will have higher availability given the dynamical change in
Device-to-Device networks.

2.3.2 Consensus Protocols
Given the heterogenous nature of IoT networks, each sub-network may
employ different consensus protocols within its Autonomous Domain (AD).
The Blockchain-based IoT infrastructure should support coordination
among different consensus protocols so that devices across ADs can
exchange data and resources.

2.4. Smart Contract
Smart contract is an agreement between two or more parties that is
defined and executed automatically, once certain pre-defined conditions
are met. For a Blockchain-based IoT network, smart contract enables
more complex device-to-device interaction than transaction.

A crucial part in execution of a smart contract is to check and
validate whether the pre-defined conditions are met. There can be two
sources where such data come from, on-chain and off-chain. On-chain
data are stored in the decentralized immutable ledger which can be
traced back to once it is packaged in the block. In some cases, the
chain is designed to only carry important information under resource
constraints, hence leave some information stored off-chain, which can
be useful in the decision making process of smart contract. Special
mechanism should be implemented to check and validate the correctness
and truthfulness of off-chain data while still keep the decentralized
nature of blockchain system.

Once the condition for transactions are met, associated fees can be
transferred from the service demander to the service supplier safely
without a trusted third party. A smart contract can call a series of
smart contracts, which makes it a powerful tool for automatic value
exchange in IoT network.

3. Different Node Types and Functions
IoT devices have various computing power, storage space and networking
capability. It is practically impossible to install a full stack of
functions on every node.

The devices, given their varied capabilities, can be divided into light
node and full node.

                              full node
                      |     smart contract     |
                      |      transaction       |
                      |submission & validation |
                      |     edge analytics     |
      light node      |       Data Storage     |
|             real-time messaging              |
|                light wallet                  |

A light node often has low memory space, weak computing power and/or
unstable connectivity to the network, such as sensors. This type of
node only perform minimal message exchange with peer nodes, keeps a
wallet with their address/name and a balance. Any heavier tasks, such
as transaction validation will be off-loading to trusted full node. The
trusted node can be one from the permissioned chain. A light node is a
client of the blockchain, but not a blockchain node.

A full node will support all the functions a light node has with higher
performance, including real-time messaging, transaction, block and file
storage, local computing, etc. The full node is a complete blockchain
node, which can submit and validate transactions, execute smart
contract. It also helps trusted light nodes with heavy tasks when

4. Security Considerations
The security of a Blockchain-based system relies on its consensus

For IoT, the possibility of being hacked poses security challenges to
the system.

5. References

Authors' Addresses
   Hui Ding
   Chaincomp Technologies Co., Ltd.
   Shixia New Times,
   Shenzhen, Guangdong 518034

   Email: hui.ding@chaincomp.net

   Zhenzhen Jiao
   Chaincomp Technologies Co., Ltd.
   Shixia New Times,
   Shenzhen, Guangdong 518034

   Email: z.jiao@chaincomp.net

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