Trusted and Transparent Asset Tracking on theEdge
An Industry IoT Consortium Tech Brief
2022-01-27

Authors:
Xinxin Fan
Head of Cryptography, IoTeX
xinxin@iotex.io
Raullen (Qi) ChaiCEO, IoTeX
raullen@iotex.ioSupply chains are the principal arteries of the global economy playing a crucial role in enabling
international trade flows. Today’s supply chains are a globally interconnected supply-anddemand networks with profound interdependencies among suppliers, distributors, retailers andconsumers. Businesses rely on it to move their assets from one part of the world to another in atimely manner. But a lack of visibility, traceability, integrity and transparency has plagued supplychain operations for decades. This has led to poor quality control across the value chain, lowadministrative efficiency, long and tedious reconciliations among stakeholders, etc., thusincreasing overall cost and affecting customer satisfaction significantly.
To tackle these industry-wide challenges, we need to focus on three aspects of supply-chain data:
1. Untrusted data: IoT devices (e.g., RFID tags, wireless sensors) that are attached to physicalassets in the supply chain are subject to a wide range of attacks that can alter the supplychain data arbitrarily and jeopardize the integrity of asset-status data.
2. Fragmented data: A supply chain involves multiple stakeholders that might not trust eachother, which creates data silos and prevents optimal decision making. Data silos and opacityof supply chains can result in broken trust and compromised value chain integrity amongstakeholders.
3. Non-interoperable data: Due to third-party IT systems and ERP solutions for data processing
and storage in the supply chain, custom integrations are often needed to parse supply-chain
data, which incurs overhead and decreases supply-chain efficiency.
The untrusted, fragmented and non-interoperable data is the root cause for many common
problems faced by the supply chain industry today, so an asset-tracking solution that can ensure
end-to-end trust and transparency across multiple tiers of the supply chain is highly desirable.
This technical brief describes how to build a trusted and transparent asset-tracking solution by
combining three technical components: secure edge devices, consortium blockchain 1 andstandardized supply chain data formats. The resulting solution facilitates collaboration amongsupply chain stakeholders, improves supply chain efficiency and user experience, and achieves
substantial cost savings.

1 TRUSTED AND TRANSPARENT ASSET TRACKING: THE THREE KEY PILLARS
1.1 SECURE EDGE DEVICES
IoT devices are widely used in physical asset tracking applications for monitoring location,temperature, humidity, movement, handling, etc. Since the data reported by IoT devices reflects
the real-time status of physical assets in the supply chain, the integrity of the data collection and1 Consortium blockchain refers to a blockchain platform operated by multiple organizations (seehttps://cointelegraph.com/explained/private-public-and-consortium-blockchains-the-differences-explained).

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transmission process is critical. To ensure data trustworthiness, edge devices must be secure. The
components of a typical secure edge device are illustrated on the left side of Figure 1-1.

Figure 1-1. A secure edge device for asset tracking

Essentially, a secure edge device leverages an Arm TrustZone-enabled microcontroller coupledwith a security sub-system to realize strong software isolation and data integrity protection. A
more detailed discussion about securing edge devices can be found in IIC’s IIoT Distributed
Computing in the Edge white paper. An instantiation of a secure edge device, Pebble Tracker(shown on the right side of Figure 1-1), has become available for building secure asset-tracking
applications.

1.2 CONSORTIUM BLOCKCHAIN
According to NIST, blockchains are tamper-evident and tamper-resistant digital ledgers
implemented without a central repository (i.e. distributed) and usually without a central
authority (i.e. a bank, company or government). There are three main types of blockchain
systems: public, private and consortium blockchains. A consortium blockchain (e.g., the IoTeXPatheon), which aims to facilitate collaboration among enterprises, is a permissioned platformgoverned by multiple organizations. A consensus protocol implemented in blockchain ensuresthat nodes agree on a unique order in which blocks are appended.2
Unlike conventional ERP solutions that mainly focus on bridging two siloed enterprise systems,
blockchain systems enable (mutually) untrusted parties to conduct business and serve as thesingle source of truth regarding the collaborative business process. Moreover, blockchain

2 https://www.investopedia.com/terms/c/consensus-mechanism-cryptocurrency.asp

3systems are able to replace trust intermediaries (e.g., notaries, escrows) by so-called smart
contracts, which are forms of code distributed on the blockchain that will be automatically
executed under certain conditions without human intervention. Smart contracts simplify trust
establishment and improve operational efficiency significantly.
Decentralization, immutability, transparency, security, resiliency and smart contracts are apromising infrastructure for documenting business interactions among stakeholders in complex
supply-chain applications. For a more general discussion about distributed ledgers and theirpotential use cases, the interested reader is referred to the Distributed Ledgers in IIoT whitepaper.

1.3 STANDARDIZED SUPPLY CHAIN DATA FORMAT
A uniform language that enables automatic and seamless data processing across a variety of IT
systems is essential; a standardized data format should be employed to resolve interoperability
issues in multi-party supply chains. For example, the Electronic Product Code Information
Services (EPCIS) is a global GS1 standard that enables supply chain stakeholders to sharetransactional information about the movement and status of physical objects as they travel
throughout the supply chain. Each EPCIS transaction contains key data elements that describe
attributes (i.e. “What”, “When”, “Where” and “Why”) of an event that happens to an item withina supply chain. With a standard like EPCIS in place, data from one stakeholder is transformed intoa standard-compliant output that can then be easily processed by other stakeholders in thesupply chain.

2 AUTHTRAIL: A TRUSTED AND TRANSPARENT ASSET TRACKING FRAMEWORK
A typical multi-party asset tracking application involves shippers, receivers and a freight-carrier
network with multiple stakeholders (e.g., manufacturer, distributor, provider, carrier) that havemutual obligations to deliver assets in time. Unfortunately, the traditional asset-tracking
solutions have posed a multitude of concerns due to the lack of trustworthy and transparent
information across the supply chain. The Covid-19 pandemic has further exposed the fragility of
the current supply chains and highlighted the need for improving the existing supply chain
infrastructure through digital transformation. To tackle the industry-wide challenges for global
supply chains, we describe a trusted and transparent asset tracking framework called AuthTrail.
The proposed framework establishes a trusted data-sharing fabric for streamlining workflow andincreasing supply chain visibility among all the stakeholders.
As shown in Figure 2-1, AuthTrail leverages a consortium blockchain to store and exchange all theinformation related to freight contracts, real-time locations, climatic conditions, transportationand handling of physical assets, thereby creating a single source of truth available to all
stakeholders in the system and eliminating potential issues like late reconciliation, improper
handling of assets, etc. Moreover, secure edge devices ensure trustworthiness of the data4

collection for the status of the attached physical assets. In particular, trusted real-time IoT data
will be fed into smart contracts, which specify the service-level agreements (SLAs) negotiatedamong stakeholders, for evaluation periodically and the penalty settlement will be triggered
automatically in the event that an SLA is breached. Finally, to create the chain of custody whenassets are moving in the supply chain, AuthTrail requires the stakeholders to record standardized
EPCIS events on the blockchain whenever the status of assets changes.

Figure 2-1. A high-level system architecture for AuthTrail

The AuthTrail framework has these major steps:
Asset tracking stakeholders onboarding. A consortium blockchain is provisioned and an
administrator sends invitations to stakeholders of the freight-carrier network for joining thesystem. Upon creating an account and logging in the system, each stakeholder generates adecentralized identifier (DID) and stores the corresponding DID document on the blockchain.
Freight contracts negotiation and archiving. All the freight contracts (e.g., broker carrier
agreements, load tenders, rate conformations, bill of lading) are negotiated offline among
stakeholders and the hashes of the digital versions of those freight contracts are committed tothe blockchain for secure logging and auditing purposes. In particular, service-level agreements
between stakeholders are written into smart contracts and deployed on the blockchain.
Secure edge device onboarding. Once a secure edge device is powered on for the first time, itgenerates a private/public key pair within the secure hardware and registers the public key on5

the blockchain via a decentralized secure device onboarding process. The registered public key isthen used to perform the on-chain sensor data verification by the smart contracts.
Real-time asset tracking. When an asset is being moved by the freight carrier network, the secureedge device captures its real-time status (e.g., location, temperature, humidity) and signs it using
the private key. Based on the location of the asset, the signed asset status is then sent to a specificsmart contract for the SLA validation.
Automatic penalty settlement. In the case that an SLA is breached, a special event is emitted on
the blockchain by the smart contract. Once the event is captured by the corresponding
stakeholders’ enterprise networks, the penalties will be automatically settled among
stakeholders involved in the SLA.
Chain-of-custody creation. The stakeholders send transactions to the blockchain when the asset
is in their custody. Each transaction encapsulates a standardized EPCIS event describing what has
happened to the asset. All the EPCIS events, which are recorded on the blockchain and shared
among all the stakeholders, establish the chain of custody of the asset in the supply chain.

3 BUSINESS OPPORTUNITIESThe unique combination of secure edge devices, consortium blockchain, and standardized supply
chain format is revolutionary in its ability to create trust among stakeholders in supply chain
applications. In addition, the increasing need to eliminate intermediaries and automate supply
chain operations are expected to provide tremendous growth opportunities for blockchainempowered asset tracking solutions. The AuthTrail framework has been dedicatedly designed tomeet the needs of the supply chain market, including, but not limited to, asset provenance, cost
reduction, workflow automation, and restoration of consumer confidence.

4 ABOUT THE AUTHORS
The views expressed in this IIC Technical Brief are the contributing authors’ views and do notnecessarily represent the views of their respective employers nor those of the Industry IoTConsortium.
Dr. Fan is responsible for directing the IoTeX's strategy and productroadmaps as well as developing the core technologies and IP portfolio.
Before joining IoTeX, he was a senior research scientist of Security andPrivacy Group at Bosch Research Technology Center North America,
where he defined and conducted innovative research on security andprivacy for Internet of Things, machine-to-machine communication,
cloud computing and data mining. He is an inventor with 17 patent filings
for innovative information security and privacy-enhancing technologies.

6Dr. Fan received his Ph.D. degree in Electrical and Computer Engineering from the University ofWaterloo.
Dr. Chai founded IoTeX in 2017 to focus on the building of auto-scalable
and privacy-centric blockchain infrastructure that is designed andoptimized for Internet-of-Things (IoT). Previously, he worked at Google
as senior software engineer leading many security initiatives for its
technical infrastructure. He was also the founding engineer of Google
Cloud Load Balancer, which now serves thousands of cloud services with
1+ million queries per second. Prior to that, he was the head ofcryptography R&D at Uber, leading the research and development ofcredential storage system, authentication system, risk management andin-house cryptographic tools. Dr. Chai received his Ph.D. degree inEngineering from the University of Waterloo.

5 COPYRIGHT
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