A DID for every thing.

Safer & better mobility through verifiable Driving Event Data Chains.

Presented by Dmitriy Gorevoy (Interlinked Protocol Labs), Andrey Orlov (Interlinked Protocol Labs), Dr. Carsten Stöcker (Spherity GmbH), Alexander Yenkalov (Interlinked Protocol Labs)

Submitted to MOBI Grand Challenge

January 10, 2019, Düsseldorf, Germany

Keywords: decentralized identity, vehicle identity, digital twinning, cryptographically secured data chains, verifiable claims, blockchain, machine learning, agile driving, data chain provenance, audit trails, reputation system


Driven by technology innovation and ecosystem growth mobility value chains are significantly changing from monolithic, closed to distributed, open systems.

Data flows are dynamically defined and stretch across multiple entities. The trustworthiness and accuracy of output data of a distributed mobility value chain is of increasing importance for the safety within a mobility system. This transformation requires new concepts of digital identity and trust for data transactions among non-human entities.

Introduction - What our solution does

Our MOBI grand challenge application presents a novel approach to establish verifiable data chains for driving event data processing. This enables the verification of a given data flow and the trustworthiness of output data. As the output data are used by several mobility control, risk and business systems it is important that any entity can evaluate the trustworthiness of a given output data set.

The decentralized identifier (DID) is a new open standard type of globally unique identifier that offers a model for lifetime scope, portable digital identity that does not depend on any centralized authority and that can never be taken away by third parties. We are using DIDs as a standard identifier in our solution which is supported by the W3C community.

Our approach uses cryptographic data structures to link data objects and to establish a method for data flow provenance [1]. By data flow provenance we mean a mechanism for tracing data item content and control through a processing system including any transformation to the data item. This includes flows with multiple sources, collective sensor fusion and processing by machine learning algorithms. Data flow provenance means not just tracing control but also verifying the end-to-end integrity of every data flow including any transformations (additions, deletions, modifications, combinations, and ML processing).

When a DID and hence data chain of the resultant data is extended to machines, the provenance chain of the data flow can provide the basis for verifiable claims and attestations about the data flow itself as well as for reputation mechanisms. These novel verifiable data chains and reputation mechanisms allow to asses trustworthiness, reliability or risk metrics of a given output of a data chain.

The applications of verifiable data chains stretch across multiple use cases including real-time vehicle value, agile driving, road and obstacle mapping, usage-based insurance (UBI), data market places, reliable feedback loops into driver assistance systems (DAS) and autonomous driving infrastructures, V2V/V2I interactions and cooperative mobility systems.

Benefits of data provenance along a digitized value chain include:

  • reliability of data and ML labels in distributed systems
  • increased safety
  • maximized efficiency with less congestion, impact, costs and better services.

Our verifiable data chain concept supports the MOBI goal of the first stage to demonstrate the pieces of the BC/DLT mobility puzzle that can be used and scaled today. We suggest evaluating our proposed data chain concept as a foundational technology for the future MOBI infrastructure.

How we built it

Decentralized identifiers (DIDs)

The resulting combinatorics of possible connections between any given set of entities in a mobility system is an impossibly large number. Yet in today's user journeys or business environments, agents (whether human, machine, or software) increasingly need to communicate, access or transact with a diverse group of these interconnected entities to achieve their goals. This requires an interoperable and ubiquitous method to address, verify and connect these elements together.

We propose to adopt the open decentralized identifier standard (DID) as an open, interoperable addressing standard and to establish mechanisms to resolve DIDs across multiple central or decentral mobility systems [2].

DIDs are the atomic units of a new layer of decentralized identity infrastructure. DIDs can be extended from identifiers of people, to any entity, thus to identify every thing. We use DIDs to help identify and manage data sets, objects, machines or software agents through their digital twins, to locations, to events, and even to pure data objects.

DIDs are derived from public private key pairs. We are using innovative cryptographic solutions for secure key management by fragmenting the private key of a DID that never exists in its entirety. Our key management solution is very effective for providing very secure signing transactions e.g. for smart phones, algorithms or data sets. An integration of the key management technology into embedded devices is on our technology roadmap.

A DID has the following required syntax:


We are using the Ethereum Blockchain and DID method ethr for our development work.


As our technology stack is blockchain agnostic any other DID method based on alternative blockchains can be integrated and used.

Verifiable claims

DIDs are only the base layer of decentralized identity infrastructure. The next higher layer (where most of the value is unlocked), are verifiable claims [3,4]. This is the technical term for a digitally signed electronic data structure that conforms to the interoperability standards being developed by the W3C Verifiable Credentials Working Group.

Verifiable claims can be either self-issued by an entity such as a machine to provide a proof about authenticity and integrity of data or they can be issued by a third party (issuer, e.g. OEM, government, TÜV, service provider, bank).

In mobility systems any entity might want to transact with any other entity. This means entities are engaging with each other in a dynamically defined, on-demand way. It is not pre-defined which entities interact among each other. To ensure efficient transactions any new entity in a mobility value chain must be able to independently verify other counter parties.

To achieve this objective, we are using the DID approach and are anchoring the verifiable claims on a distributed ledger technology to move the cryptographic root of trust from central systems into a decentral, interoperable infrastructure.

Digital twins that are verifiable

A digital twin is a digital representation of a biological entity (human, living organism, organization), a physical entity (objects, machines), a digital entity (digital asset, software agent) or any system formed of any combination of individual entities.

Digital twins can represent objects and entities as varied as a IoT sensors, ECUs, spare parts, vehicles, traffic lights, access gates, human users, or a city, and everything else in between. More recently they have started to be used to represent intangible entities like services, code, data, processes and knowledge. Digital twin data can consist of any life-cycle attributes and IoT sensor, telematics or compute data.

A verifiable digital twin is a digital twin with attributes that are represented by verifiable claims. These attributes such as a birth certificate, authentication proof, a calibration report or sensor data attestations can be independently verified by any third party.

This type of digital twin provides verifiable data about its creation, life-cycle, sensor readings, actuator commands or transactions. These verifiable data can be used for audit trails, decision making and for feedback loops in (autonomous) control systems.

Verifiable driving event data chain

A data chain is a cryptographic data structure that chains signed data objects together and establishes a method for data flow provenance. Data flow provenance allows verifying the end-to-end integrity of every data flow object and its transformations (additions, deletions, modifications, combinations, and machine learning processing).

Processing of driving event data is operational in multiple mobility disciplines. Driving event data processing can include multiple data sources, parties, algorithms and processing steps. A human or non-human end-user of driving event data chains needs to be able to validate trustworthiness and accuracy of data chain output data. This requirement becomes of critical importance when the output data is used in safety or security relevant use cases or to make economic decision with significant commercial values involved.

For establishing a verifiable data chain, we link signed objects together. The following code snippet is a payload example with a machine learning label (red traffic light), information about the algorithm that created the label (Algorithm 1) and a link to the previous data chain block (previous block ID).

"typ": "JWT",
"alg": "ES256K-R"
  "iat": 1546724123,
  "exp": 1546810523,
  "signer": {
    "type": "algorithm",
    "name": "Algorithm 1"
  "data": {
    "claim": {
      "predictionLabel": "red traffic light, red traffic signal, stoplight",
      "predictionProb": "0.983483",
      "did": "did:ethr:0xe405b9ecb83582e4edc546ba27867ee6f46a940d"
    "previousBlockId": "b86d95d0-1131-11e9-982e-51c29ca1f26e",
    "previousBlockHash": "307b817de9b7175db0ded0ea9576027efd64fb21"
  "iss": "did:ethr:0x5ed65343eda1c46566dff6774132830b2b821b35"

The data chain object can be verified by validating the signature of the payload. Cryptographic data chains enable users to validate the provenance of entire driving event data processing chains including the authenticity and integrity of the input data, the output data and the provenance of sensing devices and the processing algorithms.

We recommend to

  • establish verifiable data chains for driving event data processing,
  • provide a DID for every entity and data set,
  • integrate the data chains with DID registries (e.g. validated list of OEMs).

The verifiable digital twins are addressable by their DIDs and providing information about organizations, sensors telematics devices, data sets, external data sources, software algorithms and users involved in the data chain.

This approach is of particular value when validation or benchmarking data are available about the sensing devices, vehicles and the algorithms that are processing the driving event data. In combination with a reputation or validation system any user can calculate trustworthiness and accuracy metrics about the output data. For instance, data with provenance will have a much higher commercial value on a data market place.

As a next step, reputation methods can be integrated for both, individual digital twins and entire data chains. Further standardization work on data chain trustworthiness and accuracy metrics need to be done.

Design principles

For our digital twin and data chain integration work we are applying the following design principles:

Principle Description
From VINs to value chains Abstracting the Concept of Identity to a mobility system of vehicles, IoT, road & travel infrastructure, mobility systems, ML agents, driving event data set, autonomous driving/DAS feedback loops, markets and humans. Exchanging data among those entities. E2E data provenance along a value chain.
Blockchain-agnostic Use blockchain for anchoring attestations or verifiable claims. Decision on which blockchain to anchor claims based on user preferences or economic metrics such as Tx costs. Use of fiat-backed stable coins for micropayments.
Scalable integration Integrated technology stack consisting of off-chain data structures, serverless cloud infrastructure, secure key management, DIDs, ML agents, sensor data, data chain fusion and blockchain connectors.
Responsibility Segregation Implementation of this common pattern for micro services design that supports scalability and maintainability of our solution.
Standards Use of existing W3C, Industry 4.0 and Automotive data standards and semantic models to ensure adaptability and portability of our solution.
Business value Focusing on simple data integrity and authenticity problems within existing value chains. Retrofitting of existing infrastructures to scale adoption.

Agile driving event data chain for MOBI grand challenge

Agile driving events can be divided into two groups: (1) the interaction between a driver’s vehicle and the road environment, and (2) the interaction between a driver’s vehicle and nearby vehicles [5].

Diverse methods for enhancing driving safety have been proposed. Such methods can be roughly classified as passive or active. Passive methods (e.g., seat-belts, airbags, and anti-lock braking systems), which have significantly reduced traffic fatalities, were originally introduced to diminish the degree of injury from an accident. By contrast, active methods are designed to prevent accidents from occurring. Driver assistance systems (DAS) are designed to alert the driver - or an autonomous driving module - as quickly as possible to a potentially dangerous situation.

The two classes of driving events may occur simultaneously and lead to certain serious traffic situations. Automotive industry is working on active methods and systems including machine learning algorithms to analyze these two kinds of events and determine dangerous situations in agile driving from data collected by various sensors and data from external sources. The machine learning output labels about dangerous curves, road obstacles or poor vehicle conditions are fed into control, transaction and risk systems. In distributed mobility systems the trustworthiness and accuracy of the output labels must be independently verifiable.

Key question: How can I trust vehicle identity data, 3rd party data and machine learning labels that are created and processed along a distributed mobility value chain?

To achieve trustworthiness of output labels we are planning to blend our verifiable data chain technology with historic driving event data and black box algorithms to build a verifiable driving event solution:

  • Interoperable decentral identity and verifiable digital twinning protocol
  • Cryptographically secured and blockchain-enabled data chains
  • E2E integration of remote sensing (telematics) data and machine learning algorithms

Our approach demonstrates how the following trust problems can be addressed with DLT:

  • Vehicle provenance and configuration
  • Provenance, verifiability and integrity of the driving event input data (or telematics data)
  • Integrity and transparency of driving event data chain when multiple 3rd party intermediaries are involved
  • Credentials about benchmarking of ML algorithms and training data
  • Aggregated accuracy and trustworthiness of predicted ML labels and attributes

Challenges we ran into

Over the course of the implementation of our verifiable data chain we ran into the following challenges:

  1. Providing DID identity to individual data sets and algorithms
  2. No reference implementations for verifiable data chains
  3. No common semantic standards for automotive digital twin
  4. Lack of validated source code for scalable issuing and anchoring of verifiable claims (>100.000 Tx/s)
  5. Getting access to sensible OEM driving event data and real algorithms
  6. Lack of E2E driving event data models and architectures (location, transport, events, processing)

We solved (1.) and (2.) with our data chain implementation. We researched W3C vehicle signalling standards and semantic web as well industry 4.0 standards to address (3.).

We are testing the sidetree protocol on IPFS that might lead to a solution for (4.). We are planning to benchmark the protocol in the next weeks.

We are trying to address (5.) with BMW.

Data model implementation patterns need to be created in order to enable effective implementation of cyber physical systems (CPS). This is a general task to be done regardless of the use of DLT technology. To address (6.) we are working with the German Centre of Artificial Intelligence (DFKI) on a CPS integration methodology, a data modelling methodology and reusable data model implementation patterns for verifiable data chains.

Accomplishments that we are proud of

We accomplished the development of verifiable data chains including the following technology components:

  • DID manager
  • Secure key management
  • HD identity wallet
  • Verifiable claims
  • Deployment on severless cloud functions on AWS
  • Integration of tensor flow algorithms for image processing

We are now planning to integrate historic agile driving event data from an OEM and a black box algorithm with our existing data chain solution on Amazon Web Services.

What we learned

Our primary leanings are around the following areas of interest:

  • Abstraction of the DID method to any object
  • Identity solutions for machine learning agents
  • Scalability of off-chain data structures
  • Integration of serverless cloud infrastructure with key management and identity wallets
  • Verifiability of data chains
  • Applicability of data chains for above mentioned data-driven business solutions

What's next: our broader objective

Our broader objective is to establish a scalable digital twin protocol and a technology layer for autonomous things. We call these digital twins autonomous digital twins that are verifiable, semantic and privacy-preserving.

We are integrating further W3C and Industry 4.0 standards to establish a semantic digital twin network. Our work integrates further innovation in cryptography and privacy-preserving solutions to achieve GDPR compliance for both, the human and non-human entities.

We are looking forward to field test our solution in a complete mobility ecosystem.

Explainer Videos

Introduction to Verifiable Data Chains - Video Part II

We created a video to explain the concept of Verifiable Data Chains for driving event data processing: https://vimeo.com/310934948

Explanation of our Verifiable Data Chain Demonstrator for MGC - Video Part III

This is an explanation about our verifiable data chain demonstrator: https://vimeo.com/310937978

  • how to use it
  • how it works
  • what you see in our demo implementation

Safer & better mobility through Spherity's verifiable Driving Event Data Chains.


[1] A DID for Everything - Rebooting Web of Trust Working Draft [2] W3C DID Specification [3] W3C Verifiable Claims [4] Decentral Identity Foundation [5] Dangerous Driving Event Analysis System by a Cascaded Fuzzy Reasoning Petri Net

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posted an update

Update on our MGC Verifiable Data Chain Demonstrator

We just increased performance of our Verifiable Data Chain demo and integrated our Corporate Wallet solution for managing private keys of the entities involved in the demo.

Key management is done via vaults. Vault policies are defined in accordance to compliance requirements of an enterprise. We are using the following set-up for identities and vaults:

Account: Entities that require identity(-ies). Accounts are spaces where identities can be managed. An account can be created for human, legal entity, machine or any other physical or virtual object. Inside of accounts, we work with: Participants, Vaults and Sub-Identities. Sub-Identities are represented by wallets (key-pairs) and managed inside vaults.

Participant: Participant devices can be created within a particular account. After requesting participant creation, it needs to be activated on a dedicated iOS device or with a cloud software agents (embedded devices to be supported later), to further trace operations from vaults of the corresponding account where participant was specified as a quorum member, so that it can provide approvals for pending operations. In the essence, participant’s device, holds the secret that gives it a possibility to manipulate wallets that exist inside connected Vaults.

Vault: Vaults are managed identity groups. Vaults group a single or multiple wallets, and define quorum policies for managing them. At the time of vault creation, there is a need to specify the list of participants that will have a right to approve operations on behalf of wallets identities that can be generated within.

Sub-identity/Persona/Wallet: Each vault can have multiple wallets which are sub-identities (or personas) for of vault group or account holder. As an example, let’s consider that some wallet identity is being used to sign some data in order to build a verifiable claim. In this case, after the signing process will start, participants that correspond to a respective vault, will be notified about a pending operation. And after gathering the required number of approvals, the operation will be processed.

Vault Quorum Policy: Vault’s Quorum Policy is a rule set. Vault’s Quorum Policy is being defined at vault creation time. It describes the list of participants who participate in a quorum and the number of required approvals that need to be collected from all vault’s participants for progressing a operation (signing or joining a vault).

In case you are interested in the above, we would be happy to demonstrate the integration of vaults with legal entities, identity/device management and digital twinning for machine twins and verifiable data chains.

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posted an update

Good bye monolithic platforms, welcome to the future of dynamically defined mobility

Systemic value of data provenance through verifiable data chains

MOBI stakeholders asked us about the business value of our verifiable data chains and who our customers are. We would like to share our train of thoughts in this blogpost about the systemic value of data provenance and why we started developing our MGC submission to support MOBI's mission for ecosystem innovation.

Primer: What does the 4th Industrial Revolution mean for us?

The current speed, scope, and systems impact of technological innovation is unprecedented in human history. These massive technological advancements lead to the Fourth Industrial Revolution (4IR) which is the convergence of the physical, biological and digital spheres blurring traditional boundaries throughout existing value chain.

The transition to 4IR systems will fundamentally change the way mobility providers create value and serve customers. This transition leads to major shifts:

From ownership to orchestration. Mobility providers will differentiate largely by leveraging and integrating capabilities outside the firm to create innovative products and experiences, in contrast to the conventional reliance on owning and efficiently operating large-scale assets. By registering mobility assets and services on the blockchain ownership and access will be tokenized, meaning owners can trade their shares or their rights to use them directly through the decentral system. Shares in vehicles can change in accordance to their real time values. Ownership will be traded among human and non-human parties when algorithms show that would maximize economic benefits.

From sequential value chains to meshed service networks. Consumers are not only viewed as the end users of products, but as active participants in the supply chain, from defining product concepts, to serving as last-mile delivery couriers to providing services with their assets, data or algorithms. Roles will become increasingly blurred between suppliers, manufacturers, channel partners, consumers, devices and algorithmic agents when they exchange services. The current sequential model of monolithic value chains lack the ability to integrate efficient micro-services powered by very granular data. Response time is too slow to interact with new local mobility participants on dynamically defined on-demand markets.

From corporate structures to atomic economic entities. With blockchain-enabled mobility, all providers and consumers can equally participate in a transportation system, setting the terms, conditions and pricing they choose. As digitisation marginalizes transaction costs any atomic entity can be competitive in the future mobility system. Their autonomous digital twins enable them to make agile decisions, deliver micro-services and capture value on a microscopic scale.

The scope of the changes now underway is too vast to be addressed by incremental process and product improvements. Consequently, players that would like to stay relevant must start upgrading their products and services now for participation in 4IR.

Our hypotheses about identity in the future mobility system

We are working towards digital identity solutions that are built upon the following hypotheses:

  1. Today’s value chains are monolithic and closed or a sequence of closed value chain steps (from A to B to C). Trust is established through bilateral verification procedures. In case C trusts B and B trusts A there is no real problem, or the problems are manageable by business processes such as validation, inspection and dispute management. However, the resulting business process costs are an inherent systemic trust tax.
  2. In tomorrow’s digitised and connected world, entirely different meshed service and value networks are emerging. The set of actors interacting in open systems can be dynamically defined. Transactions are multilateral and stretching across multiple digital value chains.
  3. Data has emerged as the most valuable asset. Future mobility systems intrinsically demand that participants share their data across a value networks and markets. Therefore, trust requires a verifiable data chain mechanism for tracing data item content, control and transformation from start to end along digital value chains.
  4. Digital twins and verifiable data chains will soon scale exponentially and, therefore, their costs will be marginalised.

Technology is now breaking up the sequence of bilateral transactions in traditional value chains. Consequently, any product or service in such a system will have a verifiable digital twin identity that (1) can participate and transact with any other given counterparty on dynamically defined local markets, (2) can be independently verified by any new actor and (3) can actively verify the provenance of data in a given digital value chain.

Corporate requirements for identity vaults (secure key management)

Digital identity starts with secure key management. We are working on secure key management in accordance to corporate requirements for identity vaults of human and non-human entities.

Requirements include four eye principle, vault quorum rules, corporate identity verification, transaction audit trails, integration of machine identifiers, and processes for employees leaving or joining an organisation.

Our objective is to enable corporates to control the digital identity -- i.e. the public-private key pairs -- of their organisation, employees, machines and software agents in a secure and compliant way.

Enabling existing products and service through digital twinning

Our digital twins enable companies today to start building products and services with a digital identity and to stay competitive in tomorrow’s meshed value networks.

Therefore, we designed our digital twins to be interoperable, addressable, discoverable, verifiable (to establish trust about its attributes) and being able to engage in transactions with any other counterparty via software agents.

Digital twins are upgrading today's products and services and empowering them to participate in tomorrow's meshed value networks.

Data provenance for establishing trust in distributed systems

When more and more algorithms and sensor fusion mechanisms are injected into the mobility system the question of trust goes much beyond bilateral transactions.

To enable decisions, trust -- stretching across an entire digital value network involving multiple data sources, algorithms and actors -- is a key enabler for the network to function properly. Any control system, risk product or business processes is dependent on independent means for trust verification.

Any given data set might have many input sources that might have been manipulated before by different algorithms. Trust in a giving data sets can be established by three mechanisms:

  • Reputation systems
  • Algorithmic plausibility checks
  • Data provenance (our focus)

Data provenance is of utmost importance when safety in a mobility system is concerned. By data provenance we mean a mechanism for tracing data item content and control through a processing system including any transformation to the data item. This includes flows with multiple sources, collective sensor fusion and processing by machine learning algorithms. Data provenance means not just tracing control but also verifying the end-to-end integrity of every data flow including any transformations (additions, deletions, modifications, combinations, and ML processing).


There are problems in today's mobility systems such as tracking, tracing, audit trails, provenance and authenticity that can be addressed with our verifiable digital twins.

Digital twins provide identity for human and non-human entities that transact on open and distributed digital infrastructures. We are enabling companies today to learn and upgrade their products and services to participate in tomorrow’s highly connected and digitized mobility system.

Digital twins are foundational to enable shifts driven by 4IR, to upgrade products, to enable participation and to stay relevant.

Our verifiable data chains are not addressing a solution for existing problems in monolithic or sequential mobility value chains. They are focussing on future digital services.

Verifiable data chains are enabling OEMs and insurance companies to sell services to software agents (such as Amazon Alexa) of any human or non-human participant, to engage with risk digital twins of a given participant and to stay competitive in a world when profits are generated by highly specific algorithmic agents and connected autonomous economic entities.


[1] Klaus Schwab, WEF, 2016, The Fourth Industrial Revolution: what it means, how to respond [2] Dr. Carsten Stöcker, WEF, 2016, Goodbye car ownership, hello clean air: welcome to the future of transport [3] Dr. Carsten Stöcker, Dr. Burkhard Blechschmidt, 2017, How Blockchain Can Slash the Manufacturing “Trust Tax” [4] Klaus Schwab, WEF, 2018, Shaping the Fourth Industrial Revolution (contributing author Carsten Stöcker) [5] Gartner Research, 2018, Top 10 Strategic Technology Trends for 2018: Digital Twins [6] WEF Insights Report, 2018, Identity in a Digital World A new chapter in the social contract [7] Mauricio Zuazua, AT Kearney, 2019, The Fourth Industrial Revolution will change production forever. Here’s how

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posted an update

We did an amendment to our demonstrator by adding corporate accounts, participants and vaults incl secure key management. This improvement enables organisations to manage digital identity and the respective public private keys pairs of their devices and agents including ownership transfer.

This is a pretty important addition as we implemented corporate requirements for identity vaults (4 eye principle, corporate identity verification, Tx audit trails, vault quorum rules, processes for employees leaving and joining an organisation).

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posted an update

We are mining and anchoring the verifiable claims on a private Ethereum blockchain. Mining slows down our verifiable claim processing (and therefore our demo). We are right now researching alternative off-chain cryptographic data structures to significantly speed up the verifiable claims processing.

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