dlt.MOBI

Building the
New Economy of Movement

Vehicle and Parts
Maintenance and Repair
Sub-Wallet
Use Case and Business Requirements

MOBI VID0005/UC/2023 Version 1.1

MOBI

February 2023

© 2023 MOBI. All rights reserved.

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END OF TERMS AND CONDITIONSAUTHORS

Introduction• Rajat Rajbhandari, PhD, MOBI
• Matt Shi, MOBIREVIEWERS

MOBI is a nonprofit alliance of many of the world’s largest vehicle manufacturers,
startups, governments/transit agencies, NGOs, financial institutions, e-mobility providers,consultancies, suppliers, logistics providers, and blockchain protocols working to create
standards and build the Web3 digital infrastructure for connected vehicles and IoT
commerce.
MOBI is creating simple blockchain-based standards to identify vehicles, people, businesses,
and the Trusted Trip in order to securely exchange and share data, and pay for mobility
services, with the goal of making transportation more efficient, equitable, decentralized,
and sustainable, all while preserving the data privacy of users and providers alike. MOBI
itself is technology and ledger agnostic.
This standard provides a business case, requirements, and ultimately a specification for
creation of a digital maintenance sub-wallet. It provides a structure and information about
regular and preventive maintenance and repairs in addition to other accessorial upgrades/
updates performed on a vehicle. The specification, including data model and interfaces
for the wallet, is based on W3C Universal Wallet 2020. Finally, this document presents
a reference implementation of the wallet using MOBI’s Integrated Trust Network as a DID
registry and Citopia as a workflow implementation environment.
This standard is the result of continuous workshops, discussions, and research efforts
carried out by members of the DRIVES Program. Sincere thanks are extended to those who
contributed their unique insights.

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Roger Berg, DENSO
Andreas Freund, MOBI
Garrett Graham, Accenture
Toru Kimura, Honda
Christian Koebel, Honda
Pramita Mitra, Ford
Xiaoliang Zhu, Hitachi

CONTRIBUTORS
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Praveen Abbaraju, Hitachi
Loren Adams, Accenture
Steve Amancha, State Farm
Jun Amano, Aucnet
Alessandro Arciero, Henshin Group
Daniel Bachenheimer, Accenture
Patrick Bartsch, AWS
Massimo Belluz, Henshin Group
Roger Berg, DENSO
Majiri Birajdar, Arxum
Emmanuel Bulti, Accenture
Elena Carrasco, USAA
Joshua Cartellone, Accenture
Lucie Chabert, Stellantis
Raullen Chai, IoTeX
Alex Choo, ASJade
Nicola Cianci, Stellantis
Etienne Costet, Stellantis
Kerry Cote, State Farm

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Claudia Damari, Henshin Group
Pierre Delaunay, Stellantis
Kim Doak-Wigginton, State Farm
Leonard Dorloechter, Peaq
Steven Douglas, DENSO
Olivier Emsalem, Stellantis
Xin Xin Fan, IoTeX
Aaron Fong, Honda
Sanshiro Fukao, ITOCHU
Matteo Gandolfi, Henshin Group
Fabrizio Garetto, Stellantis
Kamil Gaweda, Arxum
Alan Gordon, Ford
Garrett Graham, Accenture
Ivan Gutierrez, State Farm
Kumara Guru, Blockedge
Kawanishi Hiromi, Mazda
Jan ten Hove, TICO
Felix Huang, DENSO

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Mikael Johansson, TICO
Yoji Kawanishi, ITOCHU
Toru Kimura, Honda
Yusuke Kitaoka, TICO
Kim Kloeppel, State Farm
Christian Koebel, Honda
Jonathan Koester, Peaq
Karthik Krishnamurthy, AWS
Subrata Kundu, Hitachi
Frederic Legrand, Stellantis
Phebe Lu, ASJade
Ishii Makoto, Mazda
Will Maney, USAA
Domenico Mangiacapra, HenshinGroup
Piyush Manocha, Accenture
Hisahi Matsumoto, Anritsu
Eiji Matsumura, Anritsu
Hideki Matsuoka, TICO
Lauren Mitchell, State Farm
Emmanuel Monzies, Stellantis
Hiroaki Murase, ITOCHU
Yasuhiro Nakamaya, AUCNET
Taro Nakata, Kaula Lab
Alberto Nasi, Stellantis
Andrea Neri, Stellantis
Keisuke Nisugi, TICO
Rodolfo Occari, TICO
Yasuhiko Ogushi, Kaula Lab
Kenji Ohashi, TICO
Shuichi Ohki, Kaula Lab
Harunobu Ohmae, ITOCHU
Katsuji Okamoto, Kaula Lab

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Shinji Omuro, TICO
Tatsuro Otsu, TICO
Larry Pang, IoTeX
Chrisitan Poulain, Stellantis
Jonas Rahm, TICO
Mathias Reinhartz, Stellantis
Futoki Saito, ITOCHU
Yoshihide Sakai, ITOCHUDavide Salerno, Henshin Group
Shoki Sato, Orico
Otto Schell, Stellantis
Paras Sethi, ParkMyFleet
Kenji Shibata, TICOMark Shih, ASJade
Kikuchi Shinichi, Mazda
Erik Skyten, State Farm
Raj Srinivas, Blockedge
Sudha Sriram, Ford
Suresh Sundararaj, Ford
Yuhei Takai, ITOCHU
Kimihito Tanaka, TICO
Leonardo Tapanelli, Stellantis
Sam Teng, ASJadeLong Tran, AWS
Nonoyama Tsuyoshi, TICO
Takashi Watanabe, Anritsu
Tony Welcome, State Farm
Ross Wheeler, State Farm
Huub van der Wouden, TICO
Hu Xu, TICO
Kubota Yasuyuki, Mazda
Xiaoliang Zhu, Hitachi
Tom Ziebro, Vitesco

MOBI TEAM
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Tram Vo, CEO + Founder
Chris Ballinger, Advisor + Founder
Rajat Rajbhandari, Working Groups Lead
Parth Bhatt, Technical Product Manager
Betul Kahya, Mobility Lead
Matt Shi, Supply Chain Lead
Griffin Haskins, Mobility Finance Lead
Grace Pulliam, Communications Manager
Kierra Maggs, Digital Media Associate

CONTACT
info@dlt.mobi

09

Relevant Standards and Regulations• W3C Universal Digital Wallet• Onboard Diagnostics• Regulations

Table Of12

• Use Case Specific Capabilities• Cross Cutting Capabilities

Contents
01

Executive Summary

02

Glossary of Terms

04

Definition of Repair and Maintenance Sub-Wallet

05

Stakeholders of Maintenance Information
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Vehicle/Fleet Owners
Dealerships and Repair Shops
Vehicle Manufacturers
Tier N Parts Manufacturers
Insurers to Vehicle/Fleet Owners
Maintenance System Vendors
Used Vehicle Marketplaces and Auction Houses
Government Regulators
Lenders to Vehicle Owners and Dealers

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Fundamental Components of a Wallet• Agent• Storage

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Attestation and Verification of Maintenance Information
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Registering Attributes of a Maintenance/Repair (0)Requesting an Attestation of a Proof (1)Attesting/Rejecting the Unattested Proof (2)Registering the Attestation/Rejection (3)Sending an Attested Proof to a Verifier (4)Verifying the Attestation (5)Sample Implementation• Integrated Trust Network as a Trust Anchor• Citopia• Self-Sovereign Digital Twins™

Problems and Value Propositions• Problems• Value Propositions

High Level Capabilities of the Sub-Wallet

31

Bibliography

MOBI VID0005/UC/2023
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Version 1.0
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MOBI
MOBI MR0002/UC/2023
VID0005/UC/2023 Version
Version 1.0
1.1

Glossary of Terms
Battery

Any source of electrical energy generated by directconversion of chemical energy and consisting of one ormore non-rechargeable or rechargeable battery cells orgroups of them.

Battery Management System

A battery management system manages a battery pack andmonitors the operating state of modules and cells, calculates
and reports various performance data, and balances theperformance of individual cells and modules.

Executive
SummaryThis document

Maintenance and repair sub-wallet is a software application that

presents a reference

provides the vehicle’s maintenance and repair-related information to

implementation of themaintenance wallet(BMS)

stakeholders. It stores the vehicle’s maintenance and repair history,

using the ITN anddetermines immediate and future needs, collaborates with other

Citopia.

applications, and presents the information to users. While doing so, theBlockchain

A blockchain is a growing list of records, called blocks,
that are linked using cryptography. Each block contains acryptographic hash of the previous block, a timestamp,
and transaction data (generally represented as a
cryptographically secure tree structure such as a Merkletree).

Decentralized Identity

A new cryptographic technology that enables entities
to assert ownership of their identity, where the identity
remains private and not disclosed during transactions indecentralized ecosystems.

Decentralized Identifier (DID)

W3C Decentralized Identifier (DID) represents a globallyunique identifier that can be resolved to a DID Document,
or de-referenced on a specific distributed ledger network,
much like a URL on the Internet.

wallet is able to assert the verifiability of the information it provides tothe users.
The objective of this document is to build a business case, requirements,
and ultimately a standard specification for a digital maintenance subwallet that provides in a standardized structure, information about
regular and preventive maintenance and repairs in addition to otheraccessorial upgrades/updates performed on a vehicle. The specification,
including data model and interfaces for the wallet, is based on W3C

Universal Wallet 2020. Finally, this document presents a reference
implementation of the wallet using MOBI’s Integrated Trust Network
as a Decentralized Identifier (DID) registry and Citopia as a workflow
implementation environment.

01© 2023 MOBI. All rights reserved.

© 2023 MOBI. All rights reserved.

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MOBI MR0002/UC/2023 Version 1.0
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Digital Twin

A Digital Twin is a digital representation of a real-world
entity or system. The implementation of a digital twin isan encapsulated software object or model that mirrors
a unique physical object, process, organization, person,or other abstraction. SSI and DIDs are needed for digital
twins to be trusted in decentralized ecosystems.

Definition of Repair

and Maintenance Sub-Wallet
Maintenance

Maintenance sub-wallet is a software application that provides the

sub-wallet provides

vehicle’s maintenance and repair-related information to stakeholders.

vehicle maintenanceIt stores the vehicle’s maintenance and repair history, determines

and repair-related

Onboard Diagnostics (OBD)

OBD 2 implementations use a standardized digital

information tocommunications port to provide real-time data in addition
to a standardized series of diagnostic trouble codes (DTCs).

stakeholders.

immediate and future needs, collaborates with other applications, andpresents the information to users. While doing so, the wallet is able toassert the verifiability of the information it provides to the users.
The wallet must act on the behalf of the vehicle owner(s), which can

Sub-Wallet

Sub-wallet is a conceptual wallet with a specificconfiguration and grouping of documents in the SSDT. The
Sub-Wallet is part of the Universal Wallet which is partof the Self Sovereign Digital Twin (SSDT). The Sub-Wallet
inherits the capability of the SSDT and includes a specific
set of verifiable credentials and data related to one specificapplication or use case. The SSDT can have multiple subwallets.

control it and ensure that it is acting on the owner’s behalf.
The maintenanceNote: For brevity, throughout this document, maintenance means

sub-wallet must act

actions taken by the vehicle owners to keep the vehicles operational ason the behalf of thewell as corrective repairs performed on the vehicle.

vehicle owner(s).

Note: In order to generalize the definition, this standard does not
specify how the wallet is implemented (e.g., in-vehicle hardware device,owner’s mobile phone), how it stores the information (e.g., in-vehicle

Verifiable Credential (VC)03

© 2023 MOBI. All rights reserved.

The W3C Verifiable Credentials Standard defines Verifiable
Credentials as “a part of our daily lives; driver’s licenses areused to assert that we are capable of operating a motor
vehicle, university degrees can be used to assert our levelof education, and government-issued passports enable us
to travel between countries. This specification provides amechanism to express these sorts of credentials on the
Web in a way that is cryptographically secure, privacyrespecting, and machine-verifiable.

device, cloud), or how it presents the information to users (e.g., invehicle dashboard, mobile app). This standard also does not specify theusers (e.g., vehicle owners, dealers, OEMs, insurers) since there is morethan one category of users of the vehicle’s maintenance history. It
also does not specify how the wallet asserts the verifiability of
the information as there is more than one method of doing so(e.g., encryption, PKI, permissionless blockchain, federated
network). Such details will be discussed in subsequent
reference implementation standards.

Business
17© 2023 MOBI. All rights
reserved.Brochure04

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Stakeholders of

Maintenance Information

MOBI VID0005/UC/2023 Version 1.1

Insurers to Vehicle/Fleet Owners
Maintenance records allow insurers to more accurately assess the risk of future vehicle
breakdowns or accidents. In the case of an accident, maintenance records can offer insight into
the vehicle’s conditions, helping to identify possible causes of the accident and assess repairs

Vehicle/Fleet Owners

needed.

Vehicle owners follow OEM suggestions regarding vehicle maintenance. Vehicle maintenance

Maintenance System Vendors

records help owners monitor their vehicle’s health and plan for future maintenance. Maintenancerecords are also useful when selling the vehicle, as it is important for owners to provide ample

These are third-party vendors that provide maintenance service guides and tools for repair

information about the vehicle’s maintenance and repair history to potential buyers.

shops and dealers. While Maintenance System Vendors are not direct beneficiaries of vehicle
maintenance records, this data is useful for improving the products they sell to vehicle owners.

Dealerships and Repair Shops
Dealerships keep electronic records of maintenance services performed on vehicles. These
records are useful in many ways, particularly for predictive maintenance.

Vehicle Manufacturers
OEMs set the maintenance suggestions and settle warranty claims. Maintenance records help

Used Vehicle Marketplaces and Auction Houses
Sellers of used vehicles like dealers, auction houses, and other such parties must accurately
price their used vehicles, which requires a clear understanding of that vehicle’s condition.
Maintenance records are very useful in determining the health of the vehicle.

determine whether a vehicle has undergone required maintenance at a certified dealership or

Government Regulators

repair shop with OEM parts.

Regulatory bodies across the globe set requirements for vehicle safety and emission checks.
Thorough maintenance records allow regulators to verify whether a vehicle has met theTier N Parts Manufacturers
Maintenance records help Tier 1 Suppliers determine whether

requirements and may provide better insight into vehicle operating conditions.

failed parts have been maintained as per required

Lenders to Vehicle Owners and Dealers

specifications.

Well-maintained vehicles are in the best interest of Lenders. Lenders helped finance the vehicle
and a well-maintained vehicle keeps the value of the lenders’ investment. Maintenance records
help prove the history, thus the value of the investment here.

05© 2023 MOBI. All rights reserved.

© 2023 MOBI. All rights reserved.

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Problems and Value
Propositions
Problems

Value Propositions
Value Proposition 1: The sub-wallet will ensure the secure storage and tamper-proofing ofvehicle maintenance and repair records while giving vehicle owners the power to easily manageand present the maintenance data as needed.

Problem 1: Absence of immutable registry of maintenance history and traceability of who

Value Proposition 2: Tamper proof and consolidated maintenance data allow vehicle

and what repairs were performed. Maintenance history collection is not streamlined; vehicle

owners to assert the vehicle’s market value by claiming regular maintenance and care of theirowners have to gather this data from multiple sources such as repair shops, vehicle internal

vehicle and revealing associated documents on request.

systems, etc.

Problem 2: Lack of detailed history of over-the-air updates performed by OEMs and/or
component suppliers and why such updates were performed.

Value Proposition 3: A standardized maintenance wallet has the potential to increase theefficiency of the maintenance and repair process. The increased efficiency of demonstratingrecords might also allow new use cases that have so far suffered from high transaction costs andimprove the vehicle evaluation process by enabling automated scanning of condition reports.

Problem 3: Lack of traceability, authenticity, and verifiability of parts replaced during
repairs and recalls. It has been estimated that automotive suppliers lost $45 billion due to the

Value Proposition 4: Maintenance wallets will help vehicle owners maintain their vehicles

distribution of counterfeit parts in 2011 alone.

in accordance with OEM-issued maintenance schedules issued by OEMs. This will help OEMs

Problem 4: According to the National Highway Traffic Safety Administration, odometer fraud

manage warranties that require the manufacturer to repair any conditions caused by defects inworkmanship or materials.

is defined as the disconnection, resetting, or alteration of a motor vehicle’s odometer with
the intent to change the mileage indicated. It is estimated that 450,000 vehicles are soldwith false odometer readings each year in the U.S., a crime that costs American car buyers$1 billion annually. In addition, odometer tampering has seen the mileage rolled back on up to
50% of second-hand cars traded in the EU, with the price of vehicles fraudulently increasing by€2,000 - €5,000 on average. The issue requires cooperation from legislators across Europe, as
the problem is greatly increased in cross-border car sales. While 5-12% of national sales involve

Value Proposition 5: The maintenance wallet can consolidate information about parts
that were replaced during the maintenance process and present such information to the
manufacturers if required due to warranty. The presence of counterfeit parts and their use in
vehicles (knowingly or unknowingly) creates several problems for OEMs, such as disputes during
warranty claims, crash risks, and loss of revenue.

vehicles with altered mileage readings, the figure rises to 30-50% for sales of imported used cars.

07© 2023 MOBI. All rights reserved.

© 2023 MOBI. All rights reserved.

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Value Proposition 6: OEMs are required

W3C Universal Digital Walletto keep logs of over-the-air updates forcrash avoidance systems. The maintenance

Universal Wallet

The purpose of this specification is to design an abstract data model

sub-wallet will be able to selectively disclose

Specifications and W3C’s

and set of interfaces that approximate a physical wallet system and its

VC Data Model will

this information to the regulatory agencies in aprovide a mechanism forstandardized format as needed. For example, the UN

presenting maintenanceadopted WP.29, UN R155, which mandates an automotive
cybersecurity management system, and UN R156, which requires

common uses1.

data with cryptographic

There are many existing software systems that manage subsets or

proofs.

supersets of the information represented in digital wallets. Thisin all vehicles a software update management system that must record thespecification aims to be compatible with those systems by allowing themsoftware and hardware version of the vehicle.

to continue to manage the information and interfaces so long as they
can be adequately described at both a data model and interface level.

Relevant Standards and

The Universal Wallet Specifications along with W3C’s VC Data Model

There are 4 categories of standards and regulations that wallet implementation may have to

Onboard Diagnostics

will provide a mechanism for vehicle owners and other stakeholders toRegulations

present maintenance data with cryptographic proofs2.

comply with:

Digital wallet

Maintenance data

specification (e.g.,collection standards

W3C Universal(e.g., OBD-2, J-OBD,

Wallet 2020)

ADR)

OBD systems give theCurrent standards of reporting vehicle diagnostic information to users

vehicle owner or repair

include the On-Board Diagnostics (OBD 2) and regional versions oftechnician access to thestatus of the various
vehicle subsystems.

OBD including EOBD2 (Europe), JOBD (Japan), and ADR (Australia). Onboard diagnostics (OBD) is a term referring to a vehicle’s self-diagnostic
and reporting capability. OBD systems give the vehicle owner or repair
technician access to the status of the various vehicle subsystems3.
OBD 2 implementations use a standardized digital communications

Regulations

port to provide real-time data in addition to a standardized series of

Maintenance data

pertaining reporting

diagnostic trouble codes (DTCs), which enable the rapid identification

reporting standards

for emissions, safety,(e.g., ISO)and repairs (e.g., EU,

and remediation of vehicle malfunctions.

US, Japan)
1 World Wide Web Consortium (W3C), “Universal Wallet 2020,” https://w3c-ccg.github.io/universal-wallet-interop-spec/ , March 04, 2022
2 World Wide Web Consortium (W3C), “Verifiable Credential Data Model V1.1, https://www.w3.org/TR/vc-data-model/
3 https://en.wikipedia.org/wiki/On-board_diagnostics

09© 2023 MOBI. All rights reserved.

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Future wallet

OBD2 standards are not designed to store/

implementations may

present maintenance history, historical DTC values,

have a persistentconnection to the OBD2
devices, run diagnostics

etc. The devices that comply with the OBD2 standard provide the VINof the vehicle. Future wallet implementations may have a persistent

periodically, and gather

connection to the OBD2 devices, run diagnostics periodically, and gather

historical DTCs.

historical DTCs.

Regulations
Vehicles whose

Federal Motor Carrier Safety Administration (FMCSA) has requirements

emissions surpasson truck maintenance and testing that not only requires the vehicle to

the EPA limit must be
repaired and re-tested.

be maintained and tested regularly but also the records should be kept

High-Level Capabilities of the
Sub-Wallet
This chapter defines

This chapter defines two categories of high-level capabilities of atwo categories of high-maintenance wallet. The first category pertains to capabilities that alevel capabilities of amaintenance wallet.

wallet shall provide to satisfy various use cases. The second category
pertains to capabilities that are common to all or most use cases (“crosscutting capabilities”).

Use Case Specific Capabilities

for a year4.

Note: “Provide” means the capability for the owner to act on behalf of the owner/vehicle in an

evident manner is critical

Periodic vehicle inspection and maintenance provides emissions control

for compliance.

for motor vehicles. These programs are set to identify and repair high-

UCC 1: Provide Verifiable Prior Maintenance Records

Tracking these repairs
and tests in a tamper-

emission vehicles to improve air quality in areas that are not attaining theautomated environment to present the maintenance information to other stakeholders.

Provide maintenance and repair records that other stakeholders can verify.

NAAQS.2 (National Ambient Air Quality Standards). The EPA sets vehicle

UCC 2: Provide Predictive and Preventive Maintenance Warnings

emission standards to be implemented by state and local governments.

Provide stakeholders with notifications about preventive, scheduled, and other maintenance

Vehicles whose emissions surpass the limit set by the EPA must be

needs.

repaired and re-tested accordingly. Tracking these repairs and tests in

UCC 3: Provide Verifiable Odometer Readingsa tamper-evident manner is crucial to verify whether a vehicle meetsregulations.
The Vehicle Maintenance Reporting Standards (VRMS) define a set ofnumerical codes used to indicate virtually any aspect of maintenance

Provide current odometer reading that a stakeholder can verify.

UCC 4: Provide Authenticity of Parts
Provide information to stakeholders that certain high-value replacement parts are authentic
and not counterfeit.

work in a structured format. VRMS was first developed by the American

UCC 5: Provide Warranty and Recall Records

Trucking Association but has now been adopted by all types of vehicle

Provide notification to the vehicle owners regarding warranty information about the vehicle,

fleets.

parts, and maintenance services.

4 “5.2.1 Records,” The Motor Carrier Safety Planner (Federal Motor Carrier Safety Administration ), accessed December 1, 2022, https://csa.fmcsa.dot.gov/SafetyPlanner/MyFiles/SubSections.aspx?ch=22&sec=65&sub=147.

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UCC 6: Authorize Payments for Maintenance Services

CCC 4: Import/Export Data

Verify maintenance services performed and trigger a payment to the service provider.

Import/export data are essential for functions like backup/recovery or storing data outside of the

UCC 7: Provide Identities and Metadata of Parts
Manage and present the public identity of the parts along with metadata describing the parts.

UCC 8: Provide Verifiable Emissions Data
Provide vehicle emissions data as required by various regional environmental regulations.

UCC 9: Provide Performance of Parts

wallet (e.g. Encrypted Data Vaults). The wallet content should be in ciphertexts and serialized.

CCC 5: Modify/Remove Wallet Content
Ability to modify/remove content of the wallet.

CCC 6: Lock/Unlock Access
The wallet can be locked and unlocked by transforming the plaintext to ciphertext and back.

Provide state of performance of parts. For example, the wallet may provide to a third party and

CCC 7: Produce Verifiable Credentials

the vehicle owner information about the EV battery state of health along with a digital proof of

Issue VCs on claims on one or more subjects and share the credential with a holder. The credential
here is based on W3C standards with use case specific standard schemas.

authenticity of the data.

Cross-Cutting Capabilities
Note: Some of these capabilities were derived from W3C Universal Wallet 2020 Specification.

CCC 1: Encrypt and Sign Transactions
The cryptographic keys in the digital wallet can be used to sign or encrypt different items (e.g.

CCC 8: Produce Verifiable Presentations
Combine one or more credentials in a way that enables verification of authorship.

CCC 9: Perform External and Internal Queries
Takes single or multiple inputs containing query and type, and returns a collection of results basedon current wallet contents.

transactions, messages, credentials, data). There could be different keys the user chooses to

CCC 10: Revocation and Expiries

sign with.

Manages information about maintenance as well as credentials provided to users. Revokes
credentials that have expired.

CCC 2: Store Public and/or Private Keys
The core function of a digital wallet is to manage and store the cryptographic keys for essentialfunctions like signing, encrypting, or hashing. The keys are crucial for wallet safety and usability.

CCC 3: Use Metadata to Reference Non-Standard Data Formats
The wallet may store data in non-standard formats. In that case, it should include metadata as areference.

13© 2023 MOBI. All rights reserved.

CCC 11: Offline Operations
Cache information about maintenance and credentials in case thewallet is disconnected from the internet.

CCC 12: Notifications
Provides maintenance information to the wallet users.

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CCC 13: Backup and Recovery

such as payment and registration. Agents may collaborate with theProvide backup and recovery of the information if it is lost from the wallet.

agents in other wallets to perform actions. For example, an agent in a
maintenance wallet collaborates with an agent in the payment wallet to

CCC 14: Selective Disclosure of Information

settle maintenance work in the vehicle.

Gives the users flexibility to selectively disclose information to other entities.

Storage

CCC 15: Delegation and Guardianship of the Wallet
Allows the users to delegate temporary ownership of the wallet to other users.

CCC 16: Emergency Access to Wallet
Allows EMS/safety regulators access to the wallet for emergency situations.

CCC 17: Communicate with Other Wallets

Storage ensures that

A set of hardware/software implementations that stores keys,

such data is available tomaintenance history data, vehicle operational state information, etc.,

the agents in the walletat all times.

in a persistent way. Storage ensures that such data is available to theagents in the wallet at all times. These two key components of a wallet(i.e., storage and agents) are illustrated below in Figure 1.

Automatically communicate with other wallets in the vehicle, such as payment wallets.

Fundamental Components
of a Wallet

Regardless of how the wallet is implemented, wallets shall include two fundamental components:

Agent
Agents may collaborate

An agent is a set of software applications working with hardware

with the agents in otherdevices. The agent acts on behalf of the vehicle owner. It sends andwallets to perform
actions.

receives messages, encrypts and decrypts information to secure theinformation, signs information and provides a verifiable presentation
about maintenance information, and manages the wallet itself. Agentsalso operate and maintain services to interact with other wallets
Figure 1. The two primary components of the wallet.

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One of the key activities an agent performs is to provide proofs of maintenance activities toother users in the form of verifiable presentations. For example, the wallet acting on behalfof the owner will present proof of maintenance to an insurance company or a new buyer.
Implementation of submitting such proofs should be based on W3C standards of verifiable
presentation.

“One of the key activities an agent performs is to provide proofs of maintenanceactivities to other users in the form of verifiable presentations. Implementationof submitting such proofs should be based on W3C standards of verifiable
presentation.”

Attestation and Verification of
Maintenance Information

The high-level workflow for attestation and verification of maintenance proofs is illustrated
in Figure 2 below. The workflow includes service provider/witness, trust anchor, and verifier.
The workflow does not include how the system handles exceptions such as a case in which a

Figure 2. Presentation of maintenance information using VCs and anchoring on a data registry.
Source: Verifiable Credentials Data Model V1.1 https://www.w3.org/TR/vc-data-model/

0Registering Attributes of a Maintenance/Repair

A prover registers attributes about maintenance in a trust anchor infrastructure. The minimum
dataset added to the trust anchor by the prover is as follows:

prover cannot find witnesses to attest its proof or a case in which the witness cannot attest the•

Verifiable ID of the prover and service provider (if applicable).

proof due to technical reasons. The maintenance attestation and verification model is based on•

Verifiable ID of the maintenance provided by a service provider.

MOBI’s Trusted Trip standards.

•

Timestamp.

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1

Requesting an Attestation of a Proof

4

Sending an Attested Proof to a Verifier

The prover requests a witness(es) (e.g., CITOPIA) to attest the proof. The minimum dataset

The prover sends the attested proof to a verifier. The minimum attributes for the attested proof

submitted by a prover to the witness for attestation is as follows:

are presented below:•

Verifiable ID of the prover.

•

Verifiable identification of driver, owner, device, vehicle, and company.

•

ID of the proof submitted for attestation.

•

Attributes about maintenance activities.

•

Attributes about maintenance activities/trips including service location, timestamps,•

Maintenance activity attestation certificates (after attestation from a witness before

documents, certificates, etc. (optional)

2

sending to a verifier):◦◦

Attesting/Rejecting the Unattested Proof

The witness verifies the identity of the prover and matches the attributes presented in a proof
with its own information. If the witness is a service provider, then it may be able to perform a full5

Certificate issuer ID = Entity that has issued the certificate after attestation.
Certificate identification (Cert ID) = Unique identifier of the certificate itself.

Verifying the Attestation

attribute match. If it is not a service provider, then the witness may attest subsets. The witness

After the verifier receives the attested proof, it will verify the IDs of the prover and the

may reject attestation on the grounds that it did not “provide” the maintenance services.

witness(es). It will consume attestation attributes to determine whether it can accept the proof
or not. Conditions to accept/reject the attestation attributes are dependent on the verifier’s

3

Registering the Attestation/Rejection

terms and conditions agreed upon with the prover.

The witness registers in the trust anchor whether it attested or rejected the proof presented
by the prover. It may include justification for attestation or rejection. The minimum dataset
submitted by a witness after attesting/rejecting a proof is as follows:

19•

Verifiable identification of the witness and the prover•

ID of submitted proof•

Result = attested or rejected•

Reason(s) for rejection (industry standard enumerators)•

Timestamps of attestation/rejection•

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Sample Implementation

Integrated Trust Network as a
Trust Anchor

In this implementation,

In this implementation, Citopia leverages the ITN to attest the identity

The ITN is a member-

The Integrated Trust Network (ITN) is a member-owned and operated,

Citopia leverages theof a vehicle owner as well as any maintenance activities performed onowned and operated,

protocol-agnostic digital infrastructure to provide trusted identity

the vehicle (assuming vehicle and repair shops have been onboarded

protocol- agnostic digital

ITN to attest the identityof a vehicle owner aswell as any maintenanceto Citopia). Such attested information can be presented by the vehicle

activities performed onowner (prover) to other third parties. This implementation allows forthe vehicle.

the verifiable and trustable presentation of the vehicle’s maintenanceinfrastructure to provide
trusted identity services.

activities. The implementation architecture is illustrated below:

services for connected mobility and IoT commerce. Citopia, a federated
Web3 marketplace, uses ITN core services to provide identity services
for all parties involved in maintenance activities.

Citopia
Citopia is a member-

Citopia is a member-owned and operated federated Web3 marketplace

owned and operated

for connected mobility and IoT commerce where ecosystem stakeholders

federated Web3
marketplace where
ecosystem stakeholders

can securely meet, message, and transact. Citopia facilitates theonboarding of Self-Sovereign Digital Twins™ (SSDTs™), which are used

can securely meet,

to issue, verify, and store VCs and initiate interactions for automating

message, and transact.

multiparty transactions in the Web3 economy.
For the maintenance use case, SSDTs™ of dealers, repair shops, andvehicles would be onboarded onto Citopia. This would provide themwith verifiable digital agents in the ecosystem with the capability toissue, verify, and store VCs for the maintenance workflow.

Figure 3. Maintenance Sub-wallet Roles and Information Flow. Referenced W3C Verifiable
Credential Model21© 2023 MOBI. All rights reserved.

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Self-Sovereign Digital Twins™
An SSDT™ is a digitalA digital twin is a virtual representation that serves as the dynamic digitaltwin which is anchoredcounterpart of a physical object or process, owning and managing bothin a decentralized trust
network using W3C’s
Decentralized IdentifiersStandard.

its historical and real-time data.
An SSDT™ is a digital twin which is anchored in a decentralized trust
network using W3C’s Decentralized Identifiers (DIDs) Standard (for
MOBI’s community, this is the ITN). The controller of the SSDT canparticipate as an autonomous economic agent in trusted transactions

Citiopia SSDT Wallet capabilities:•

Identity/lifecycle traceability•

Components lifecycle traceability•

Data/digital assets traceability•

Payment and settlement traceability

The Citopia SSDT is an abstraction layer and represents users’ capabilities on the network. The
SSDT includes the following technical components:•

for both REST APIs and Decentralized Identity Foundation

by issuing VCs and Verifiable Presentations (VPs) per W3C’s VC Standard.

(DIF) DIDcomm messaging protocol for integration with ITNT Core Services, other

For MOBI’s community, this is done using Citopia Marketplace.

Digital Twins, and Legacy Application via REST APIs•

A Vehicle SSDT will include technical and wallet capabilities listed and			Authentication service utilizing OAuth2 for REST APIs and DIF DID AuthN for DIF
DIDcomm messaging

shown in the figure below. On the left-hand side is a list of capabilities•

An implementation of the W3C Universal Wallet for key and document management(“Technical Capabilities”) that perform cross-cutting functions such•

An implementation of the W3C VC Issuance and Verification standard both asas providing information about the SSDT to external services via API,
identity services, and performing business applications. On the right-

REST APIs and as DIDcomm endpoints•

hand side are wallets for different use cases.

Citopia SSDT SDK capabilities:

23

					
API Endpoint Service•

ITN trusted identity services•

Mutual identity recognition•

APIs to communicate with other SSDTs•

APIs to communicate with legacy systems•

Zero-knowledge implementations•

Multiparty business automation© 2023 MOBI. All rights reserved.

Implementation of mobiNET Data Sharing APIs both as REST APIs and as DIDcomm
endpoints•

An implementation of ITN Core Services functionality via DIF DIDcomm•

An implementation of the W3C/DIF Encrypted Data Vault for document storage
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Sub-wallet and Verifiable Credential Type
When the data or

Each Sub-Wallet stores data for a specific use case. When the data or

credentials are needed,

credentials are needed, the SSDT would query the related data from thethe SSDT would query
the related data from the
Sub-Wallet to present todata. In the maintenance use case, the vehicle SSDT may query the data

the verifier or issue new

in the maintenance sub-wallet and share it with insurance companies tocredentials.

verify the vehicle history.

Sub-Wallet is a specific

Sub-Wallet is a specific configuration and grouping of documents in theconfiguration and

SSDT. The Sub-Wallet’s storage is implemented as an Encrypted Data Vault

grouping of documents(EDV.) The Universal Wallet is implemented following W3C Universal

in the SSDT. The SubWallet’s storage is

Figure 5. Citopia SSDT and Maintenance Sub-wallet

Sub-Wallet to present to the verifier or issue new credentials from theWallet specification. The specific set of documents (ex. maintenance andimplemented as an

repair documents) are stored in the EDV. The Universal Wallet acts as the

Encrypted Data Vault

interface to the EDV. Being part of the SSDT, the Sub-Wallet inherits the(EDV.)

capability of the SSDT. The SSDT can have multiple sub-wallets.
In the example shown below, maintenance and repair performed by anentity will be described in type “Mobi-Maintenance-Repair” definedwithin the maintenance credential. Inside the credentialSubject, anothertype attribute that helps future define the specific maintenance is “20kUniversal Wallet

maintenance” and specific services performed on the vehicle.

Each SSDT would contain a W3C-compatible Universal Wallet offering convenient access todifferent digital assets (credentials, cryptocurrency, data, etc.) in place of carrying different
wallets.

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MOBI VID0005/UC/2023 Version 1.1{

MOBI VID0005/UC/2023 Version 1.1{"@context": ["https://www.w3.org/2018/credentials/v1","https://www.w3.org/2018/credentials/examples/v1"],"id": "http://example.edu/credentials/3732","type": ["VerifiableCredential", "Mobi-Maintenance-Repair"],"issuer": "https://example.edu/issuers/565049","issuanceDate": "2010-01-01T00:00:00Z","credentialSubject": {"id": "did:example:ebfeb1f712ebc6f1c276e12ec21","vid": "did:example:abfeb1f712ebc6fsd76e12ec22","VIN": "JTERU5JR7M5861131","Model": "XXX","milage": "20753","batterySOH": "99%","maintenance": {"type": "20k-Mile-Maintenance","name": "20k Mile Scheduled Maintenance","Services": ["Oil Change", "Tire Rotation", "Air Filter Replacement"]}}}"@context": ["https://www.w3.org/2018/credentials/v1","https://www.w3.org/2018/credentials/examples/v1"],"id": "http://example.edu/credentials/3732","type": ["VerifiableCredential", "Mobi-Maintenance-Repair","Battery-Passport"],"issuer": "https://example.edu/issuers/565049","issuanceDate": "2010-01-01T00:00:00Z","credentialSubject": {"id": "did:example:ebfeb1f712ebc6f1c276e12ec21","vid": "did:example:a bfeb1f712ebc6fsd76e12ec22","VIN": "JTERU5JR7M5861131","Model": "XXX","milage": "20753","batterySOH": "99%","maintenance": {"type": "EV-Battery-Maintenance","name": "EV Battery Scheduled Maintenance",}}}

Figure 7. Sample Vehicle Maintenance Credential with Routine Maintenance Info

Figure 8. Sample Vehicle Maintenance Credential with Battery Passport TypeThe Maintenance

The Maintenance and Repair Credential could also be a Battery Passport

The SSDT will identify and group this specific type of credential for the Maintenance Use Case. In

and Repair Credential

Credential, part of the Battery Passport Sub-wallet. In the example below,

the same way, there could be types for Battery Passport, Certificate of Origin, Charging History,

Besides type “Mobi-Maintenance-Repair”, “Battery Passport” is also

etc.

could also be a Battery
Passport Credential, partof the Battery Passport

specified in the array.

Sub-wallet.

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Bibliography“5.2.1 Records.” The Motor Carrier Safety Planner. Federal Motor Carrier Safety Administration.
Accessed December 6, 2022. https://csa.fmcsa.dot.gov/SafetyPlanner/MyFiles/SubSections.
aspx?ch=22&sec=65&sub=147.
“Fighting Mileage Fraud on Used Cars: News: European Parliament.” Fighting mileage fraud on
used cars | News | European Parliament, May 29, 2018. https://www.europarl.europa.eu/news/
en/headlines/society/20180525STO04312/fighting-mileage-fraud-on-used-cars.
“Overview of Vehicle Inspection and Maintenance (I/m) Programs - Program ...” U.S. Environmental
Protection Agency, October 2021. https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P1013CC0.pdf.
Plant, Rachael. “The Benefits of VMRS for Maintenance Reporting.” Atom. Fleetio, May 20, 2021.
https://www.fleetio.com/blog/maintenance-reporting-vmrs.
“WP.29 Consulting: Automotive Cybersecurity.” AUTOCRYPT, August 31, 2022. https://autocrypt.
io/services/wp-29/.

31© 2023 MOBI. All rights reserved.