What Is a Blockchain Self-Sovereign Identity? SSI Explained

Self-Sovereign Identity (SSI) will offer better security, privacy, and safety than digital identities like Google or Facebook-based sign-ups.

Digital identity usage is increasing among the public and businesses. These days, you can use your Google or Facebook profile to sign in to public websites like Chick-fil-A, Domino’s, eBay, Instagram, and so on. However, these digital identities are prone to hacking incidents and may reveal more information about you than you realize.

SSI is the next-gen digital identity that can secure your log-ins in personal and professional setups.

What’s the Concept of SSI

SSI will function as a tamper-free digital identity based on blockchain technology. When you use SSI to log in for any services, you’ll control the data related to your identity and not the service provider. Online service providers will also experience increased system efficiency and business opportunities by giving you more control over your data.

SSI works in a simple way where an issuer will issue digitally signed documents for you. The issuer will also establish document trust through a blockchain network. You’ll receive your documents in a digital wallet, mostly a blockchain-based app. You could even use government and private services, using the SSI wallet app to authenticate your identity digitally.

SSI democratizes online identity sharing by enabling you to decide what kind of data and at which level you want to share with the web pages or apps.

The Technology Behind SSI

Blockchain is the fundamental technology behind SSI, like the Ethereum blockchain. Decentralized Identifiers (DID) play a key role in setting up secure identities. Blockchain participates as a trusted source for DID publications or revocation registry transactions.

The followings are the most important elements of SSI:

1. Decentralized Identifier

Illustration of DID component of SSI system

A decentralized identifier (DID) is equivalent to a unique personal identity. Document issuer will create DIDs in a censorship-resistant blockchain environment. There will be an encrypted link of the DID to a signed document by an authority.

The digitally signed document contains crucial information related to service endpoints and authorized public keys. There are many registered DID methods like Hyperledger Indy, W3C, Ethereum, and Bitcoin.

Related: What Is a Blockchain Protocol and Why Is It Important for Crypto?

DID is a simple code that contains a Uniform Resource Identifier (URI) scheme, an identifier of the DID method, and a DID method-specific identifier. The DID document will contain this DID code along with information for cryptographic authentication of a DID controller.

2. Verifiable Credentials

A flowchart graphics showing SSI concept

Verifiable credentials attest information to a specific DID. These are the important standards of any SSI ecosystem. For example, a digital driving license that allows you to drive cars is one example of a verifiable credential.

For a public scheme and social services SSI ecosystem, a government agency will create digitally verifiable identity profiles or DIDs for the beneficiaries. Such DIDs will save beneficiary information like name, SSN, date of birth, age, etc. The agency will also store these DIDs in a blockchain-based network.

Image showing illustrative verifiable credentials or VCs

When an eligible person approaches the service point to use a social or public service, the service provider can effortlessly authenticate the beneficiary from the DID exchange. The verification uses digital systems, like scanning a QR code. It saves you and the service provider from administrative delays.

The DID holder needs to store its digital identity in a secure wallet app. During credential verification, the user might also get a one-time password to authenticate the process. Service providers, like banks, will only see encrypted codes rather than personally identifiable information or PII.

3. Ethereum Standards for SSI

Illustration of Ethereum as a blockchain for SSI

When developing an SSI ecosystem based on the Ethereum blockchain, the following Ethereum standards play crucial roles:

  • ERC Lightweight Identity designates the smart contract Ethereum DID registry. It’s a one-time deployable registry. However, it also works as a common resource for every user in the blockchain network.
  • EIP-780 Ethereum Claims Registry allows for creating, getting, and deleting identity issuing claims. Any authorized government agency or public service provider issues claims to its beneficiaries through a bytes32 type key.
  • The hashing standard for Ethereum-based SSI is EIP712. It facilitates the digital signing of typed structured data.
  • When running SSI on an Ethereum blockchain, the ERC-1484 protocol aggregates DID data.
  • EIP-1078 protocol of an Ethereum blockchain enables password-free sign-ins for the SSI ecosystem.
  • Organizations, groups, humans, machines, and bots will use unique, recognizable proxy profiles in any SSI system. ERC-725 will define the standard protocol for such proxy accounts or profiles.

What Are the Benefits of Self-Sovereign Identity?

SSI technology will benefit both the service provider and the beneficiaries. Access systems based on SSI will become transparent, easily auditable, free from human error, and more secure.

1. Health Care Data Privacy

Illustration of health care data management

Governments around the world enforce patient medical record privacy as a mandatory compliance practice for the health care industry. Lumedic Exchange is the pilot project that ensures patient data privacy by transmitting health care records through SSI-based authentication between hospitals, insurers, and drugstores.

2. Restricting Contagious Diseases

A visual representation of stopping disease causing microbes

The International Air Transport Association (IATA) scrutinizes global air travelers to prevent contagious diseases. The best working example is restricting COVID-19 spread through IATA Travel Pass. Through SSI technology, IATA instantly identifies the vaccination and COVID-19 test status of any passenger.

3. Effortless Staff Identification

SSI can improve employee identification systems for access to company resources in a cost-effective way. Such a digital identification system also facilitates unrestricted movements during emergencies.

NHS England issued NHS Staff Passport for its health workers like doctors and nurses. This SSI-based identity verification system allows efficient movement of essential workforce during crises like pandemics, epidemics, etc.

4. Faster Financial Services

Illustration of fast and effortless financial transactions

SSI technology can increase the processing speed of the financial services sector. For example, Bonifii’s MemberPass® is an SSI-based identity authentication system that resolves many problems related to Credit Union services in the USA.

5. Establishing Citizen Identity

Residents of any nation can use SSI-based verification to use services like banking, social security, education, health care, taxation, etc., in a faster and secure way. SSI4DE is such a system managed by the German Federal Ministry of Economic Affairs. The scheme allows for easier national identification of German citizens for public and private needs.

6. Effortless Financial Regulation

Visualization of regulation of financial transactions

Legal Entity Identifier (LEI) verification allows for auditing of offshore or cross-country financial services. SSI technology can also improve the efficiency of this process.

The GLEIF or Global Legal Entity Identifier Foundation of Switzerland is an exclusive database for high-quality LEI information. The foundation utilizes SSI technology for transaction authentication.

SSI Puts You in Control of Your Identity

You can keep control of your data and identity while availing of private or public services through a few clicks using SSI technology. SSI platforms like Everest, uPort, and Evernym are already working with government and private bodies to offer SSI-based access to services. As the technology relies on blockchain, your identity is virtually unhackable.


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