Argentina’s capital to launch digital identity protocol QuarkID based on zkSync Era

QuarkID: Digital identity protocol based on zkSync Era

Summary

Buenos Aires, the capital of Argentina, will launch QuarkID, an open source digital identity protocol based on blockchain, to simplify the process of local citizens accessing public services. The QuarkID wallet is jointly developed by Extrimian, an on-chain digital identity solution company, and Matter Labs, a zkSync Era developer. It integrates document storage through the zkSync Era chain framework, and zkSync Era serves as the settlement layer of the QuarkID platform. The complete roadmap of QuarkID will be released at the end of the year.

Citizens of Buenos Aires will be able to download the protocol’s native wallet to receive important personal documents such as birth and marriage certificates. Starting in November, citizens will be able to access proof of income and academic records in their digital wallets.

Digital identity refers to the digital representation of the identity information and attributes of an individual or organization in a network environment. Digital identity can be used to verify and authorize various services and transactions, such as accessing websites, making payments, signing contracts, etc. The security, privacy and convenience of digital identity are important foundations of the network society.

Blockchain technology is a distributed ledger technology that can achieve decentralized, tamper-proof and transparent data storage and transmission. Blockchain technology can provide a trusted infrastructure for digital identity, and realize autonomous management of digital identity, cross-domain mutual recognition and data sovereignty.

QuarkID is an open-source blockchain-based digital identity protocol designed to simplify access to public services for citizens in Buenos Aires, Argentina. The QuarkID wallet was developed in collaboration between the government and on-chain digital identity solutions company Extrimian and zkSync Era developer Matter Labs, and integrates document storage through the zkSync Era blockchain framework, which serves as the settlement layer of the QuarkID platform. QuarkID's full roadmap will be released by the end of the year.

This article will introduce QuarkID's background, goals, architecture, functions and advantages, and look forward to its future development direction.

Background of QuarkID

Argentina is the second largest country in South America, with a population of about 45 million. Buenos Aires, the capital of Argentina, is the country's largest city and one of the most important cultural, economic and political centers in South America, with a population of about 3 million.

The Buenos Aires City Government has been committed to improving the quality of life and social welfare of citizens and promoting innovation and development in the city. The city government provides a variety of public services, such as education, medical care, transportation, social security, etc. In order to access these services, citizens need to provide various personal documents, such as birth certificates, marriage certificates, income certificates, academic certificates, etc.

However, these certificates are currently in paper or electronic form, which poses the following problems:

- Insecure: Paper documents are easy to be lost, damaged or forged; electronic documents are easy to be hacked or leaked.

- Inconvenience: Citizens need to carry or keep multiple documents and submit or verify them repeatedly between different institutions.

- Opaque: Citizens cannot control the use and sharing of their own data, nor can they trace the source and history of their data.

To address these issues, the Buenos Aires City Government decided to introduce QuarkID, an open source digital identity protocol based on blockchain.

The main goals of QuarkID are to:

- Simplify the process for citizens to access public services and improve efficiency and convenience.

- Protect citizens’ data security and privacy, and achieve data sovereignty and autonomous management.

- Promote collaboration and mutual trust among public services and enhance transparency and credibility.

- Promote the application and innovation of blockchain technology in urban governance.

The core architecture of QuarkID consists of three parts:

QuarkID Wallet, zkSync Era, QuarkID Protocol

QuarkID Wallet

A native mobile device-based application for citizens to create and manage their own digital identities and access various public services. The QuarkID wallet was developed in collaboration between the government and Extrimian, an on-chain digital identity solution company, and adopts an international standard digital identity model, namely Self-Sovereign Identity (SSI).

SSI is a method that allows individuals or organizations to fully own and control their digital identities without relying on any centralized institution or platform. The core concepts of SSI include:

DID (Decentralized Identifier): A unique, persistent, resolvable, verifiable, revocable, and tamper-proof digital identifier used to represent the subject of a digital identity. DID follows certain grammatical rules, such as `did:method:idstring`, where `method` represents the method or protocol used by the DID, and `idstring` represents the specific identifier of the DID. For example, `did:quarkid:1234567890` represents a DID using the QuarkID method.

DDO (Decentralized Identifier Document): A data structure containing DID-related information, used to describe the properties and services of DID. DDO usually includes the following parts:

- `@context`: Defines the terms and namespaces used by DDO.

- `id`: indicates the DID corresponding to the DDO.

- `controller`: represents the controller of the DDO, that is, the entity that can modify or revoke the DDO.

- `verificationMethod`: Indicates the verification method used by the DDO, that is, the public key or other mechanism that can verify the DDO signature or encryption.

- `authentication`: represents the authentication method used by the DDO, i.e. the mechanism by which the identity of the DID subject can be proven or acted on its behalf.

- `service`: represents the service provided or used by the DDO, that is, a mechanism that can interact with the DID subject through some protocol or endpoint.

VC (Verifiable Credential): A data structure containing certain claims that indicate that a digital identity subject possesses certain attributes or qualifications. VC usually consists of the following parts:

- `@context`: defines the terms and namespaces used by the VC.

- `type`: indicates the type of VC, such as `VerifiableCredential`, `BirthCertificate`, etc.

- `issuer`: represents the issuer of the VC, that is, the entity that is responsible for the claims in the VC and provides proof.

- `issuanceDate`: indicates the issuance date of the VC.

- `expirationDate`: indicates the expiration date of the VC (optional).

- `credentialSubject`: represents the subject involved in the statement in the VC, that is, the entity to which the attribute or qualification proved by the VC belongs.

- `proof`: represents the proof of VC, that is, the mechanism for signing or encrypting VC.

VP (Verifiable Demonstration): A data structure containing one or more VCs, used to show a verifier that a digital identity subject possesses certain attributes or qualifications. VP usually includes the following parts:

- `@context`: defines the terminology and namespace used by VP.

- `type`: indicates the type of VP, such as `VerifiablePresentation`, etc.

- `verifiableCredential`: Represents one or more VCs contained in a VP.

- `holder`: represents the holder of VP, that is, the entity that presents VP to the validator.

- `proof`: represents the proof of VP, that is, the mechanism for signing or encrypting VP.

The QuarkID wallet allows citizens to interact with public service agencies by generating a unique and tamper-proof DID and scanning QR codes or other means. Citizens can collect, store, display and share various VCs in the QuarkID wallet, such as birth certificates, marriage certificates, income certificates, academic certificates, etc. Citizens can freely choose which VCs to display or share, and when to withdraw or delete VCs. Citizens can also view their own data usage and sharing history in the QuarkID wallet, as well as evaluate and provide feedback on data usage and sharing.

zkSync Er

A blockchain expansion solution based on Zero-Knowledge Proof (ZKP) to improve the performance, security and privacy of the QuarkID platform. zkSync Era was developed by Matter Labs, the developer of zkSync Era, based on the Ethereum network and using ZKP technology to achieve high throughput, low latency, low cost and high privacy on-chain transactions and smart contracts.

ZKP is a cryptographic technique that allows a prover to prove to a verifier that a statement is true without revealing any other information. zkSync Era uses a general ZKP system called PLONK that can support calculations and verifications of arbitrary complexity.

zkSync Era serves as the settlement layer of the QuarkID platform, used to store and verify data such as DID, DDO, VC and VP generated and exchanged in the QuarkID wallet, as well as to process transactions such as payments and transfers involved in the QuarkID platform.

QuarkID Protocol

A protocol that defines the rules and standards for interaction between various participants in the QuarkID platform, used to ensure the compatibility, interoperability and scalability of the QuarkID platform. The QuarkID protocol was developed by the government and Extrimian, referring to digital identity-related standards and specifications developed by international organizations such as W3C (World Wide Web Consortium), DIF (Decentralized Identity Foundation), OIDF (Open Identity Federation), etc.

The QuarkID protocol includes the following aspects:

- QuarkID method: A method that defines how to create, resolve, update, and revoke a DID, following the DID Core Specification developed by W3C. The QuarkID method uses `quarkid` as its method name, and defines the corresponding DID syntax, DDO structure, verification method, authentication method, service type, etc.

- QuarkID Wallet Interface: An interface that defines how to implement QuarkID wallet functions on mobile devices, following the Digital Wallet Interoperability Specification established by DIF. The QuarkID Wallet Interface defines how to generate and manage DIDs, how to claim, store, display and share VCs, how to communicate with other wallets or services, etc.

- QuarkID VC Model: A model that defines how to represent and verify VCs, following the Verifiable Credential Data Model developed by W3C. The QuarkID VC model defines the type, format, content, and proof of VCs, and designs corresponding VC templates based on different public service scenarios.

- QuarkID VP Model: A model that defines how to represent and verify VPs, following the Verifiable Presentation Data Model developed by W3C. The QuarkID VP model defines the type, format, content, and proof of VPs, and designs corresponding VP templates based on different public service scenarios.

- QuarkID Service Interface: An interface that defines how to interact with public service agencies, following the OpenID Connect Protocol developed by OIDF. The QuarkID Service Interface defines how to request, provide, verify and withdraw VC and VP, as well as how to handle related authorization, authentication and payment.

Features of QuarkID

Key features of the QuarkID platform include:

- Digital identity creation and management: Citizens can generate their own DID in the QuarkID wallet and interact with public service agencies by scanning QR codes or other means. Citizens can view and modify their DDO in the QuarkID wallet, as well as add or delete verification methods, authentication methods and services.

- Digital certificate collection and storage: Citizens can collect various VCs in the QuarkID wallet, such as birth certificates, marriage certificates, income certificates, academic certificates, etc. Citizens can view and manage their VCs in the QuarkID wallet, as well as back up or restore VCs.

- Digital certificate display and sharing: Citizens can display or share their VC or VP in the QuarkID wallet to access various public services, such as education, medical care, transportation, social security, etc. Citizens can choose which VC or VP to display or share, and when to withdraw or delete VC or VP in the QuarkID wallet.

- Data usage and sharing traceability and evaluation: Citizens can view their own data usage and sharing history in the QuarkID wallet, as well as evaluate and provide feedback on data usage and sharing. Citizens can view the source, purpose, scope, time, etc. of data usage and sharing in the QuarkID wallet, and rate or comment on the satisfaction, trust, impact, etc. of data usage and sharing.

QuarkID Advantages

Key benefits of the QuarkID platform include:

- Efficient and convenient: Through the QuarkID wallet, citizens can access a variety of public services in one stop, without having to carry or keep multiple paper or electronic documents and repeatedly submit or verify them between different institutions. Through zkSync Era, the QuarkID platform can achieve high-speed, low-cost on-chain transactions and smart contracts without waiting for long confirmations or paying high fees.

- Security and privacy: Through ZKP technology, the QuarkID platform can minimize the disclosure of data, that is, only display or share necessary data without leaking any redundant information. Through blockchain technology, the QuarkID platform can achieve data immutability, that is, any modification or deletion of data will leave a traceable record. Through the SSI model, the QuarkID platform can achieve autonomous management of data, that is, citizens fully own and control their own data without relying on any centralized institution or platform.

- Transparency and Trust: Through blockchain technology, the QuarkID platform can achieve data verifiability, that is, any data can be verified through mechanisms such as digital signatures or encryption. Through open source protocols, the QuarkID platform can achieve data interoperability, that is, any participant who follows the same standards and specifications can interact with the QuarkID platform. Through data traceability and evaluation mechanisms, the QuarkID platform can achieve data feedback, that is, any data use and sharing can be supervised and evaluated.

Outlook

The QuarkID platform is currently in the pilot phase, and its full roadmap will be released by the end of the year. In the future, the QuarkID platform will continue to improve its functions and advantages and expand its application scope and influence. Specifically, the QuarkID platform will:

- Support more types and formats of digital documents, such as passports, driver's licenses, ID cards, etc., to meet the needs of citizens in different occasions.

-Support public services in more areas and industries, such as finance, e-commerce, tourism, entertainment, etc., to improve citizens' quality of life and social participation.

-Support the mutual recognition of digital identities in more regions and countries, such as cooperating with other South American countries or EU countries to promote cross-border mobility and exchanges of citizens.

-Support more forms and channels of data feedback and evaluation, such as through social media, online surveys, blockchain voting, etc., to enhance citizens' data awareness and sense of responsibility.

-Support the introduction and integration of more technologies and innovations, such as the use of artificial intelligence, the Internet of Things, big data, etc., to enhance the intelligence and flexibility of the QuarkID platform.

The QuarkID platform is an open source digital identity protocol based on blockchain, which aims to simplify citizens' access to public services in Buenos Aires, the capital of Argentina. The QuarkID platform realizes the creation, management, collection, storage, display, sharing, traceability and evaluation of digital identity through three parts: QuarkID Wallet, zkSync Era and QuarkID Protocol, and has the advantages of efficiency, convenience, security, privacy, transparency and trustworthiness. The QuarkID platform is currently in the pilot stage, and will continue to improve its functions and advantages, and expand its scope of application and influence in the future. The QuarkID platform is a forward-looking and innovative digital identity project that provides a new perspective and model for urban governance and social development.