TODO: write a real abstract

This document represents a concise but limited collection of use cases readers should review alongside the VC API Specification.

Comments regarding this document are welcome. Please file directly on GitHub, or send them to public-vc-comments@w3.org (subscribe, archives).

Abstract

Fundamentally, the Verifiable Credential API (VC-API) is a standard developed to give technologists a way to enable holders of VCs to use them how and where they choose. Verifiable Credentials make claims which may be a qualification, achievement, quality, or piece of information about an entity's background such as a name, government ID, payment provider, home address, or university degree. The use cases outlined here are provided to help make progress toward possible future standardization and interoperability of the transport of both low- and high-stakes claims as outlined in the VC Use Cases. The use cases in this document focus on concrete scenarios that the technology defined by the group should address.

This document represents a concise but limited collection of use cases meant to be reviewed alongside the Verifiable Credentials API.

Work on this document is ongoing and subject to change as the conversation around the VC API evolves in the main group. This should currently be treated as a draft document and as such will have errors. As the VC API gets closer to a completed specification, this document should reflect the current understanding and status of that work.

Comments regarding this document are welcome. Please file directly on GitHub, or send them to public-vc-comments@w3.org (subscribe, archives).

Introduction

The VC-API Working Group at the W3C is developing standards for exchanging Verifiable Credentials that have been verified by a third party and to make them easier for holders to use on the Web and in life.

Importance of this work

Entities (people, organizations, devices) need to make many kinds of claims as part of their everyday activities. As more and more of these important activities move to the Internet, entities need to be able to transmit instantly verifiable claims (e.g., about their location, accomplishments, value, what-have-you). From educational records to payment account access, the next generation of web applications will authorize entities to perform actions based on rich sets of credentials issued by trusted parties. The Holders of these claims, in the form of Verfiable Credentials, need to be able to take the claims they control and make use of them where, when, and how they wish, often in ways the original issuer of the VC may not have originally indended. Having a common, standard way for these Holders of claims to use them as they wish is vital to a person having control of their own data.

Standardization of the transport layer for digital claims makes it possible for many stakeholders to interact with their desired counterparties, without being locked into proprietary platforms.

Use case model

This document presents an aggregate use case model, comprised of Needs, Roles, Tasks, and Sequences. Taken together, these models define the use cases that the VC-API Working Group has addressed.

User needs define the problem space addressed by Verifiable Credentials. User Roles specify the roles different entities play when interacting with Verifiable Credentials. Tasks define the functions users can accomplish, and sequences demonstrate how tasks might be realized, by interactions between entities over time.

As with all models, this use case model is neither exhaustive nor complete. The listed uses cannot capture all possible use cases. Similarly, the models do not completely characterize the use cases represented. However, the combined model is intended to provide specific, coherent guidance for the work ahead.

The model used here draws heavily from the Verifiable Credentials Use Cases model. This is due to the fact that the VC-API is meant to support the transport of VCs in the use cases considered for the Verfiable Credential Working Group.

User Roles

There are three roles supported by Verifiable Credentials as defined by the VCWG: Issuer, Verifier, and Holder. In the VC Use Cases, a fourth role — that of subject — is defined. However, for the purposes of the VC-API, the subject is not relevant except when the same entity is both the Holder and the subject. For this reason, the Subject role does not appear in the VC-API.

VC-API User Roles
VC-API User Roles

The above roles were those defined for the VCWG, however, due to the way most production software on the internet works, for the purposes of the VC-API there arises the need to delve into some detail as to how the Issuer and Verifier roles are structured. This is due to the fact that there are many use cases where one company is making use of services to handle part of the technology stack. This has led to both Verifier and Issuer splitting into two entities each, henceforth refered to as components of the Issuer and Verifier: Issuer Service, Issuer Coordinator, Verifier Service, and Verifier Coordinator.

VC-API Role Components
VC-API Role Components

The respective Service and Coordinator components combine to fulfill the role of the Issuer and Verifier as described in the VCWG. It is fully expected by the VC-API that software will exist that may fulfill only part of any of the roles, by implementing any combination of these component roles: Issuer Service, Issuer Coordinator Verifier Service, and Verifier Coordinator.

Issuer Service
The component that creates, generates, and delivers a Verifiable Credential — which contains a some set of claims made by the Issuer Coordinator about one or more subjects — to the Issuer Coordinator.
Issuer Coordinator
The component that deals with business rules and policies around a user's request for a particlar claim to be issued.
Verifier Service
The component performing the verification of a Verifiable Credential containing claims about a given subject.
Verifier Coordinator
The component that deals with business rules and policies around a user's request for a particular Verifiable Credential to be verified.
Subject
The entity about whom a claim is made.
Holder
A role an entity may perform by possessing one or more verifiable credentials. A holder is usually, but not always, the subject of the verifiable credentials that they are holding. Holders store their credentials in credential repositories.

User Needs

The VC-API address user needs in a number of key domains:

VC-API User Needs
VC-API, Example Domains for User Needs

Education

The education domain includes all levels of the educational experience; from primary through professional continuing education.

E.1 Digital transcript
A couple of years after Joleen succussfully started an "extended transcript" program at the Unniversity she works for, the administration has decided to issue all transcripts digitally. As such they upgrade the system to make use of Education Credential Issuer Inc's issuing service, and put together a new web page to act as their issueing coordinator. Once the system is in place, Joleen pushes an email notification to the student body, both past and present, that they can now receive digital transcripts at the newly created website to the digital wallet of their choice.
E.2 Taking a test
Eunice is about to take her ACT (a test used to evaluate her readiness for college). When she arrives at the testing center, she is required to present identification. She presents her government-issued identity credential in the form of a QR Code to the test runner, who scans it. The test runner's device acts as the verification coordinator, which makes use of the ACT orginization's verification service to verify the presented identification credential. Everything checks out with Eunice's identification and she sits down to take the text.
E.3 Transferring schools
Rocky is an undergraduate student at Wossamotta U. His school provides a credential repository service to all students and alumni, so he chooses to use it. In his third year, Rocky decides to transfer to Moosylvania Tech. They do not offer a service, but he does not want to continue to use the service of his old (and now rival school) so he moves his verfifiable credentials to the service offered by his bank without needing to have them reissued.
E.4 Online classes
In MOOC and other online learning systems, being able to reliably identify participants is vital to ensure the individual evaluation and certification. Nick is participating in a course online and takes a test. He is required to provide his credentials to prove his identity before the test, which he does in the form of a government-issued idenfication credential. MOOC uses a backend verification service which verifies these, and once they are satisfied that Nick is who he says he is, have Nick take the courses he signed up for. At the end of the courses, MOOC then uses their proprietary issuer service to provide Nick a verifiable credential to the wallet of his choice regarding the results of his test.

Retail

The retail domain encompasses all things where there is an exchange of value on an individual level. This includes brick-and-mortar store fronts, web-only venues, and even person-to-person sales.

R.1 Address verification
Francis has found the perfect pair of shoes. When processing orders, Giant Shoe Company wants to be certain that his shipping address is accurate (inaccurate addresses are very expensive in terms of customer service). They offer a discount for customers who make verifiable addresses available as part of the checkout process. Francis offers a verifiable credential--containing a claim by a known authority that a specific address has been verified--to Giant Shoe Company's verifier coordinator, which verifies Francis's address, making use of Generic Verfifier Service Inc. Francis gets the perfect shoes for even less than he expected.
R.2 Adult beverages
June goes to her local beer and wine store to buy a bottle of wine. She submits a proof-of-age credential that lets the liquor store owner know that she is over 21 without having to reveal her actual date of birth, her address, or her state ID number. The store makes use of their Point of Sale Vendor's verification service which intigrates into the Point of Sale so the clerk has an easy UI to use during the transaction.
R.3 Fraud detection
On a bright Sunday, Oskar remembers that he still needs to buy his wife a precious gift for their wedding anniversary. However, he is acutely aware that it is precisely in weekends that gangs set up fraudulent web shops that claim to sell such gifts, while in fact they only take the cash, and disappear on Mondays. So before actually purchasing a gift from the web shop of his choice, he requests the shop to provide a credential issued by the chamber of commerce, that contains proof of legitimacy. After having verified that the shop is legit, by making use of the Verifier Service built into his digital wallet which receives the proof of legitimacy, he can purchase his gift.

Finance

The Finance domain includes banking, brokerage, insurance, and other industries where there is a high value placed on knowing exactly with whom you are dealing.

F.1 Reuse know your customer
Jane is opening an account at MidBank in Finland. As part of that process, the bank asks her to provide two from a variety of possible sources to confirm her identity — a so-called "Know Your Customer" check. She goes to the bank website, logs in, and navigates to the KYC page. She then selects the government-supplied verifiable credentials that confirm she receives postal mail at a certain address and that she has a national ID card. She submits these to Midbank's verification coordinator. MidBank has their own verification service, which checks the provided credentials, and confirms that they are properly issues, and still valid, credentials issued to Jane. Confirming these allows the bank to open her account and be confident in her identity when she conducts transactions.
Now that the account is open, Jane is issued, by MidBank's Issuer Service, a digitally-signed credential for her checking account at MidBank. This credential verifies that Jane has an account at MidBank and has access to her associated checking account. Since MidBank (and all banks in Finland) are required to perform "Know Your Customer" checks on accounts, this credential can also be used as sufficient verification by other financial institutions. This can help Jane assure destination banks that she is verified, thereby allaying concerns about misdirected transactions and money laundering.
F.2 Money transfer
Susan wants to send funds to her family in another country via a popular money transfer service. She has verifiable credentials in her credential repository that can be used to share her identity profile. She has also been sent a credential from her family verifying their banking information. By sharing these with the money transfer service, which have decided to make use of TopBank's Verification Service, they can automatically verify the source and destination of funds, thus being confident in the delivery of those funds and satisfying various regulations regarding prevention of money laundering.
F.3 Closing account
John opens a checking account at Big Bank Co and is issued a verifiable credential indicating that the account exists, that the bank verified John's identity, and that John has access to the account. To receive these credentials, John goes to Big Bank Co's website, selecting his prefered wallet as the destination. Some time later, John is moving to a new city and decides to close that account. Big Bank Co needs to revoke that claim as part of their normal account closing process. When John later goes to do KYC with the New Bank Co, in his new city, he mistakenly submits his old Big Bank Co account credential as part of the KYC process. New Bank Co's verification service flags this credential as revoked, and New Bank Co's website asks John for additional info.
F.4 Trying out a new service
Nikita has several accounts with BigBank, as well as a brokerage account with WallStreetCo. She had placed all of her claims in a credential repository at BigBank that came free when she opened her accounts. WallStreetCo is now offering a new repository that has an interface she thinks she will prefer. Nikita copies her claims from BigBank into the repository at WallStreetCo to experiment with their service, but continues to use the service from BigBank while she is testing.
F.5 New bank account from home
Alice wants to open a new bank account. BigOnlineBank offers the ability to do this from home if she can provide electronic credentials. She offers government-issued certificates that verify her attributes (address, national identity number, etc.), and opens her new account from her couch. As part of this process, BigOnlineBank has stood up their own verification and issueing services. Once they have verified Alice's credentials, they then notify Alice that she can collect her proof of account credential from the provided link at her leisure.

Healthcare

Privacy is critically important in the healthcare industry. This domain looks at everything from physical interaction to connecting patients and providers with service organizations.

H.1 Prescribing
Barney is a physician, and has recently become board certified in his state. The state's board makes use of the international Medical Certificate Issuer to issue credentials that adhere to the international standards for medical practitioners. Upon completing his state's board certificate test, Barney is issued a verifiable credential confirming that he is certified to practice medicine in that state. Barney can now use this credential when writing prescriptions and referrals, thereby improving accountability and verifiability.
H.2 Online pharmacy
iPharmacy receives a prescription for Bob electronically from a local clinic. It includes a certificate about the physician that issued the prescription as well as one about Bob. iPharmacy's system automatically verifies the ability of the physician to write prescriptions, as well as Bob's insurance coverage. When Bob arrives to pick up his medication, iPharmacy further correlates his identity with the certificate, thereby improving the end-to-end accountability of their system.
H.3 Insurance claim
Tracy has a sore throat soon after moving to a new town. She finds a physician through her health care network and goes in for treatment. She is a new patient, so the clinic needs to know who she is and how she will be paying. When checking in, she presents her verifiable credential that demonstrates her identity attributes and her proof of insurance, which is checked by the clinic using the issuer service provided by the Medical Office Supply Co. When the clinic submits this to the insurance company, they can automatically ascertain that she submitted her proof of identity and insurance to the provider, and granted the physician the ability to submit the claim for payment.
H.4 Traveling illness
John is on the vacation of a lifetime, travelling the world. Falling ill, he visits a health clinic in a country in which he does not live. At the clinic, he is asked for proof of identity. He provides a credential that verifies his name and address, but elects not to disclose his marital status nor his social security number, as those are neither requested nor required at this clinic. He further marks the disclosure as expiring in 30 days—he does not want his information verifiable after that time. The clinic verifies these credentials, making use of Medical Office Supply Co's verification service after John submits the credentials to their administrative staff at the clinic via QR Code.
H.5 Proving Legal Disability Status
Trina, who is legally blind, is currently unemployed, and needs to use the local free disability ride service to get to the employment office. To use this service, she is required to verify that she maintains legal disability status. Trina provides her government-issued disability credential to sign up for the ride service, and is not required to disclose her specific disability to the ride service, as this could put her at personal risk. As the ride service is only checking very specific credentials, they have created their own verification service to use. Once Trina's credential has been verifies, they issue her a credential which gives full access to their service.

Professional Credentials

In many aspects of life it is important to know that entities are who they say they are, and that they can do what they say. Professional accreditation is one way of learning about the abilities of an entity. Being able to verify these credentials is essential to their value.

C.1 Find a doctor
Jason is looking for a new primary care physician. His health provider includes information on their web site about the physicians they have on staff, including verifiable credentials about their education, board certification, and continuing education. Jason would like assurance that these are legit physicians, and so downloads the provided credentials and submits them to the Open Medical Board Verification Service, a national organization that checks the validity of medical claims for the public. Once submitted, and verified, Jason is confident that his new physician satisfies his requirements.
C.2 Busy doctor
Barney was a board-certified physician, but he ran out of time to complete his continuing education requirements and his certification lapsed. Since the board can revoke his certification, credential verifiers will automatically be aware that he can no longer issue prescriptions or perform medical procedures. However, Barney finds himself on a cruise where a fellow cruise enjoyer has fallen over, in clear pain. Barney applies first aid until the cruise doctors can get there. As part of the cruise ship's inquiry to the event, for liability reasons, Barney provides them, via email, his revoked physician credentials, along side his, still valid, first aid certificate. The cruise doctor reviews these after they are verified by the Generic Verifier Service that the cruise ship uses, and sends Barney a response email thanking him for the assistance.
C.3 Bad university
Jane was issued a certificate by BigTraining Co., indicating that she was a trained Project Manager. It was later discovered that BigTraining Co. was not actually training anyone, and their organization's authority to issue Project Manager certifications was revoked via the US Department of Education's Accreditation Database. Jane's credential is therefore invalid, and when Jane goes to submit the credential received from BigTrainin Co. at her next job, she is notified by the company she is applying to that her credential is not valid.
C.4 New employer
Jessica is a medical doctor practicing in the United States. She has a variety of digital claims that explain her qualifications, schooling, continuing education achievements, and board certifications. These are all stored in the credential repository provided by her employer. When she is offered a position with another health provider network, she can automatically transfer all of these claims to her new employer.
C.5 Social authority
Josie is a healthcare worker that has created a profile on a professional social network to make herself readily available for new opportunities in the workforce. She lists her employment history and credentials including degrees, certificates, and digital badges. The website requests verification of her claims in order for her credentials to be visible when she posts messages. Josie authorizes the sharing of the relevant claims with the website, and the site verifies them, making use of their partner, Workplace Credential Verifier Service, before allowing Josie to expose them.
"Freedom?" is an online forum that encourages free discussion about issues controversial in Freedonia. The forum allows users to register anonymous accounts, but it also allows users to obtain badges based upon real-world certifications. Paula has been certified as an aid worker, and wishes that information to be marked on her posts. She shares her certificate with the forum, but limits it to only verifying that she is the holder of the certificate, that she is the subject of it, and that she is an aid worker. In this way she maintains her anonymity in this controversial forum while still being able to assist her fellow countrymen.
C.6 Job applicant
Software Co. has posted an open position online and they are receiving thousands of applications. Cindy has applied for the job. Unlike many applicants, she has attached her education credentials—college degree, additional specific software training, etc. Software Co. evaluates these credentials, using the international Education Verification Service, which was stood up by a group of international univerisities to make the verification of education credentials easy, as they receive her application. Because her materials are verifiable and verified, her application is immediately forwarded as a viable candidate.

Legal Identity

For many transactions, an entity must be able to prove some aspect of their identity in a way that can be quickly verified. Governments and other widely recognized entities are well positioned to provide such identification in a verifiable digital form.

L.1 Digital driving license
Asako just passed the final test to receive a drivers license. As she is still a new driver, and may be pulled over for a traffic violation, she would like to receive a credential that asserts a claim that she has right to drive a car. She requests a credential on the certifying authority's website, (issuer) that she can use to prove to the officer (credential verifier) that her claim is valid. The certifying authority and officer both make use of the state's issuing and verifier services, respectively, as they are both state entities.
L.2 Seamless immigration
Tom is a frequent international traveler. In order to speed processing through immigration check points, he applies for a digital passport from his governmental authority. After satisfying background check requirements, by submitting a few credentials requested by the government authority, the authority issues Tom an electronic version of his passport. This version is verifiable and retains a history of all the places he visits so that immigration officials can quickly and easily evaluate his suitability as a visitor to their country. Once they are satisfied, they will automatically add the details of this new visit to Tom's passport.
L.3 Speedy air travel
Security for air travel is more and more rigorous, requiring more and more time to validate each passenger. Ivan has a collection of verifiable credentials that are assembled into his air travel Identity Profile. When Ivan needs to pass through a security checkpoint at his airport, he presents this profile before entering the line. Because his identification can be immediately and automatically verified, by the TSA's verification service, he is permitted to skip the long line and go straight to the metal detector.
L.4 Refugee crisis
Thousands of people each year are displaced because of man-made and natural disasters. Anoushka is one such, having been forced to flee her village along with her mother and younger brother. They reach an IFRC center just across the border in a relatively safe area, but with no documentation. Since the government of her homeland is in turmoil, there is no way for the IFRC staff to easily establish their identities. Fortunately, Anoushka had been issued a self-sovereign proof of birth, attached to which is the proof of birth and marriage for her parents. She is able to retrieve this because it is available from many places, including the Internet. Since it is verifiable, the IFRC is comfortable vouching for them and resettling them in a safer area for the duration of the conflict.

Devices

Intelligence devices are created and deployed so that they can interact with other entities (people, organizations, devices). Establishing trust and maintaining secure relationships with these devices is especially critical.

D.1 Devices during manufacturing

Bob, the director of production at HVAC Manufacturing, issues a device-identifying verifiable credential (e.g. IDevID, IAK) at the factory for an energy-saving fan controller IoT device. HVAC Manufacturing provides Bob with the front end software for this, and has stood up their own, custom, issueing service for use company wide.

Carol, senior quality engineer at Certifications Testing Lab, issues a certification of specification-compliance verifiable credential to the fan-controller device at the certification lab during the manufacturing process. Certifications Testing Lab provides Carol with the front end software to do this but makes use of the international Fan-Controller Standards Group's issueing service, which requires attestations of the engineer making the final claims about the device, before it will issue the specification-compliance certificate.

When the fan controller is installed at the customer's office at Modern Office Spaces, the controller's identifying credential can be verified by Sam, IT technician, to establish the identity of the controller as part of the on-boarding of the new controller. The controller's specification-compliance credential is verified to demonstrate the controller's Energy-Star compliance. Sam's handheld scanner makes use of Scanner Co's verification service, a package deal with the device.

D.2 Devices during delivery

As the fan controller leaves the factory, additional verifiable credentials are issued by Vince, a systems engineer at VAR Resellers, as he verifies the manufacturer's configuration matches the verifiable credentials accompanying the device. For this process, VAR Resellers has stood up their own verification and issueing services to be used within the company. He then installs a software package specific to Modern Office Spaces needs and issues verifiable credentials that establish evidence of possession by VAR Resellers and the software additions Vince made to the device.

Finally, upon delivery to Sam, the end customer, the verifiable credentials show that the fan controller has been securely handled and contains the correct features and certifications.

D.3 Devices setup for operating autonomously

Sam, the new device owner, needs to trust the device originated from HVAC Manufacturing and was handled correctly at Certifications Testing Lab and installed with the correct software package at VAR Resellers. After Sam verifies each of the verifiable credentials, using Generic Online Verifier's online service. He issues another verifiable credential for fan controller #37 which includes assertions relating to trust: device manufacturer model/version, software manufacturer model/version, security versions of components TCB, and associated devices the fan controller is authorized to interact with including thermostat-board-room. To do this, he goes to HVAC Manufacturing's website and requests the new credential by scanning his new device's barcode and submitting an image to HVAC Manufacturing's website. After verifying the device is one of their, HVAC Manufacturing issuer's Sam the requested credential.

The thermostat-board-room monitors room temperature. When the temperature is too hot it switches the fan controller #37 on and later when the temperature reaches a comfortable level, off. The device makes sure the control signals from thermostat-board-room are authorized (namely, that Sam intended for thermostat-board-room to control the fan controller). To do this, Sam decides he trust's HVAC Manufacturing to verify these types of credentials for him, and so he puts the end-point provided by HVAC Manufacturing for these types of purposes into his fan-controller's settings page.

Sam is concerned about the security of the smart board room. He configures the autonomously interacting devices to re-verify device trustworthiness attributes periodically by re-checking that the device originated from HVAC Manufacturing and was handled correctly by Certifications Testing Lab and installed with the correct software package by VAR Resellers. For this purpose, Sam does not trust HVAC Manufacturing's verifier service, as there could be a conflict of interest there, so Sam instead decides to use Generic HVAC Verifier's verification service, adding the provided end-point to the approriate configuration files so the devices use his selected verification services.

Sam may update the device’s software occasionally during its lifetime. Even though Sam is applying the update, VAR Resellers supplies the correct update. The device ensures that only VAR Resellers is able to supply the updated software image and that only Sam is able to apply the update.

Focal Use Cases

Get Digital Permanent Resident Card

Lana is an IT administrator for the United States Citizenship and Immigration Services (USCIS) Digital Permanent Resident Card (PRC) program. She configures the USCIS website to issue digital Permanent Resident Cards by utilizing industry standard issuer software and setting up the appropriate HTTP API Authorizations between systems. Legal Permanent Residents, upon receiving their physical card in the mail, are given the USCIS website URL, a login account, and PIN code that they may use to manage their account and pick up their digital Permanent Resident Card. When Louis, a Legal Permanent Resident, requests a digital Permanent Resident Card via the USCIS website, he authenticates using his login account and once authenticated, provides a DID associated with his client-side digital wallet against which the website will issue VCs. The USCIS website then connects to the digital card issuing server, which builds the Verifiable Credential Permanent Resident Card using Louis' account data, and then utilizes industry standard HTTP APIs to issue the Permanent Resident Card as a Verifiable Credential. Louis can then use his Digital Permanent Resident Card in online scenarios when he needs to prove his resident status, such as when applying for a job.

Requirements:

Mermaid

            sequenceDiagram
              autonumber
                Lana (Issuer Admin)->>uscis.gov (Issuer App):Configure to properly use Generic Issuer SAAS
                uscis.gov (Issuer App)->>uscis.gov (Issuer App):Process configuration
                uscis.gov (Issuer App)->>Generic Issuer SAAS (Issuer Service):Status check
                Generic Issuer SAAS (Issuer Service)->>Generic Issuer SAAS (Issuer Service):Verify Authorization
                Generic Issuer SAAS (Issuer Service)->>Generic Issuer SAAS (Issuer Service):Check business rules
                Generic Issuer SAAS (Issuer Service)->>uscis.gov (Issuer App):All good
                uscis.gov (Issuer App)->>Lana (Issuer Admin):Configuration complete
                authn.io (Holder Service)->>Louis's Browser (Holder App):Holder-App/registerCredentialHandler
                Louis (Holder)->>Louis's Browser (Holder App):uscis.gov
                Louis's Browser (Holder App)->>uscis.gov (Issuer App):uscis.gov
                uscis.gov (Issuer App)->>Louis's Browser (Holder App):uscis.gov/index.html
                Louis's Browser (Holder App)->>Louis (Holder):uscis.gov/index.html
                Louis (Holder)->>Louis's Browser (Holder App):Click "Get PRC"
                Louis's Browser (Holder App)->>uscis.gov (Issuer App):uscis.gov/getPRC
                uscis.gov (Issuer App)->>Louis's Browser (Holder App):request authentication
                Louis's Browser (Holder App)->>Louis (Holder):request authentication
                Louis (Holder)->>Louis's Browser (Holder App):provide authentication details
                Louis's Browser (Holder App)->>uscis.gov (Issuer App):uscis.gov/authenticate?louiss-details
                uscis.gov (Issuer App)->>uscis.gov (Issuer App):process provided authentication details
                uscis.gov (Issuer App)->>Louis's Browser (Holder App):authentication succuss
                Louis's Browser (Holder App)->>Louis (Holder):authentication succuss
                uscis.gov (Issuer App)->>Louis's Browser (Holder App):Holder-App/requestPresentation
                Louis's Browser (Holder App)->>Louis (Holder):Holder/selectHolderService
                Louis (Holder)->>Louis's Browser (Holder App):holderServiceSelection
                Louis's Browser (Holder App)->>authn.io (Holder Service):HolderService/requestPresentation
                authn.io (Holder Service)->>Louis (Holder):Holder/selectWallet
                Louis (Holder)->>authn.io (Holder Service):walletSelection
                authn.io (Holder Service)->>Louis (Holder):Holder/selectProfile
                Louis (Holder)->>authn.io (Holder Service):profileSelection
                authn.io (Holder Service)->>Louis's Browser (Holder App):HolderApp/requestedPresentation
                Louis's Browser (Holder App)->>uscis.gov (Issuer App):IssuerApp/requestedPresentation
                uscis.gov (Issuer App)->>Generic Issuer SAAS (Issuer Service):IssuerService/credentials/issue?"providedVP"
                Generic Issuer SAAS (Issuer Service)->>uscis.gov (Issuer App):IssuerApp/credentials/issued?"issuedCredentailsWrappedByIssuerApp"
                uscis.gov (Issuer App)->>Louis's Browser (Holder App):HolderApp/newCredential?"issuedCredentialUnwrappedByIssuerApp"
                Louis's Browser (Holder App)->>Louis (Holder):Holder/selectHolderService
                Louis (Holder)->>Louis's Browser (Holder App):holderServiceSelection
                Louis's Browser (Holder App)->>authn.io (Holder Service):HolderService/storeCredentials?"credentials"
                authn.io (Holder Service)->>Louis (Holder):Holder/selectWallet
                Louis (Holder)->>authn.io (Holder Service):walletSelection
                authn.io (Holder Service)->>Louis (Holder):Holder/selectProfile
                Louis (Holder)->>authn.io (Holder Service):profileSelection
                authn.io (Holder Service)->>authn.io (Holder Service):Store credentials
                authn.io (Holder Service)->>Louis's Browser (Holder App):HolderApp/credentialsStored
          
UC6.1 Mermaid

Contributed by: Digital Bazaar

Author Email: msporny@digitalbazaar.com

Author Github: msporny

Refresh Expired Over Age Token

Riley has onboarded into the TruAge digital age verification system, which has provided her with a set of Verifiable Credentials that she stores in her digital wallet. A subset of the Verifiable Credentials that she has received are digitally signed single-use age tokens that only assert that she is above the age of 21 and are marked as "used" by the TruAge system when they are submitted as a part of an age-restricted goods purchase, such as buying a bottle of wine. Eventually, Riley runs out of single use age tokens in her digital wallet. The digital wallet keeps track of which tokens have been used and once all tokens have been consumed, contacts a refresh service endpoint listed in one of the TruAge credentials that provides new over-age tokens. The digital wallet requests a new set of tokens by hitting the HTTP API of this VC-refresh service listed in the “refreshService” array and POSTing the original Verifiable Credential containing the refresh service description. The HTTP API ensures that it has received a valid credential and reissues a set of new digitally signed single-use age tokens in the response.

Requirements:

Mermaid


              sequenceDiagram
                autonumber
                  Riley's Wallet (Holder Service)->>Riley's Wallet (Holder Service):Notice out of Age Tokens
                  Riley's Wallet (Holder Service)->>TruAge Website (Verifier App):truage.com/credentials/refresh?"HolderCallbackURL1"
                  TruAge Website (Verifier App)->>Riley's Wallet (Holder Service):ackRequest
                  TruAge Website (Verifier App)->>Riley's Wallet (Holder Service):HolderCallbackURL1/"Domain&Challenge w/ request for expired VC + TruAgeCallbackURL1"
                  Riley's Wallet (Holder Service)->>TruAge Website (Verifier App):ackResponse
                  Riley's Wallet (Holder Service)->>Riley's Wallet (Holder Service):Generate VP containing Age Verification VC
                  Riley's Wallet (Holder Service)->>Riley's Wallet (Holder Service):Sign generated VP
                  Riley's Wallet (Holder Service)->>TruAge Website (Verifier App):TruAgeCallbackURL1?"AgeVerificationVP + HolderWalletCallback1"
                  TruAge Website (Verifier App)->>Riley's Wallet (Holder Service):ackResponse
                  TruAge Website (Verifier App)->>TruAge Website (Verifier App):Extract contained VC
                  TruAge Website (Verifier App)->>TruAge Website (Verifier App):Check if subject of contained VC is signer of VP
                  TruAge Website (Verifier App)->>Generic Verifier SAAS (Verifier Service):genericverifier.com/presentations/verify?"AgeVerificationVP"
                  Generic Verifier SAAS (Verifier Service)->>TruAge Website (Verifier App):ackRequest
                  Generic Verifier SAAS (Verifier Service)->>Generic Verifier SAAS (Verifier Service):Process provided VP
                  Generic Verifier SAAS (Verifier Service)->>TruAge Website (Verifier App):truage.com/presentations/verified?"VerificationResult"
                  TruAge Website (Verifier App)->>Generic Verifier SAAS (Verifier Service):ackResponse
                  TruAge Website (Verifier App)->>TruAge Website (Verifier App):Evaluate VP verification result
                  TruAge Website (Verifier App)->>Generic Verifier SAAS (Verifier Service):genericverifier.com/credentials/verify?"AgeVerificationVC"
                  Generic Verifier SAAS (Verifier Service)->>TruAge Website (Verifier App):ackRequest
                  Generic Verifier SAAS (Verifier Service)->>Generic Verifier SAAS (Verifier Service):Process provided VC
                  Generic Verifier SAAS (Verifier Service)->>TruAge Website (Verifier App):truage.com/credentials/verified?"VerificationResult"
                  TruAge Website (Verifier App)->>Generic Verifier SAAS (Verifier Service):ackResponse
                  TruAge Website (Verifier App)->>TruAge Website (Verifier App):Evaluate business rules
                  TruAge Website (Verifier App)->>Generic Issuer SAAS (Issuer Service):genericissuer.com/credentials/issue?"AgeVerificationVC"
                  Generic Issuer SAAS (Issuer Service)->>TruAge Website (Verifier App):ackRequest
                  Generic Issuer SAAS (Issuer Service)->>Generic Issuer SAAS (Issuer Service):Generate new Age Tokens
                  Generic Issuer SAAS (Issuer Service)->>TruAge Website (Verifier App):truage.com/credentials/issued?"Container Credential + Age Verification VC + NewSingleUseAgeTokenCredentials"
                  TruAge Website (Verifier App)->>Generic Issuer SAAS (Issuer Service):ackResponse
                  TruAge Website (Verifier App)->>Riley's Wallet (Holder Service):holderWalletCallback2?"NewAgeTokenCredentials"
                  Riley's Wallet (Holder Service)->>TruAge Website (Verifier App):ackRecieve
            
UC6.2 Mermaid

Contributed by: Digital Bazaar

Author Email: msporny@digitalbazaar.com

Author Github: msporny

Execute Multi-stage Presentation Workflow

Description: Ignio, a logistics manager for "Kirk Company", would like to submit all necessary paperwork to send his company's products across international boundaries. These products are considered hazardous chemicals and thus are regulated, requiring extra paperwork to be filed before transportation is approved across boundaries. Some hazardous material shipments are different resulting in different required paperwork, and Ignio wants to automate as much of the process as possible with Shippers, their 3rd Party Logistics company (3PL). There are a set of verifiable credentials that Ignio is willing to share with Customs as well as the transportation company.

When Kirk starts a shipping workflow, his company's systems initiate the workflow by contacting a known location on the Shipper's Website. A presentation exchange occurs to first DIDAuth the company and send generic mandatory information for any shipment; if and only if the information provided requires additional information‒in this case a hazmat certification‒a second exchange is initiated to request this outstanding/required hazmat info. Once this is received, Shippers can send back a Bill of Lading in VC form. The two (or more) credential exchanges are composable and idempotent, ending in a valid BoL if successful.

Requirements:

Mermaid

              sequenceDiagram
                autonumber
              Ignio (Logistic Manager)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Verify all necessary info ready to ship
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Ignio (Logistic Manager):Display requested data
              Ignio (Logistic Manager)->>Ignio (Logistic Manager):Evaluate data
              Ignio (Logistic Manager)->>Ignio (Logistic Manager):Decide ready to ship
              Ignio (Logistic Manager)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Trigger shipment
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):shippingco.com/createShipment?"KirkCallbackURL"
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Ack Request
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Evaluate business rules
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Generate nonce for VP Challenge
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Generate VP Request
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):KirkCallbackURL?"Domain&Challenge + Shipping Info + ShippingCoCallbackURL1"
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):Ack Request
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Evaluate Business Rules for requested Shipping Info
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Generate challenge response VP which contains requested Shipping Info VCs
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):ShippingCoCallbackURL1?"ChallengeResponseVP + KirkCallbackURL2"
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Ack Response
              Shipping Co. Website (Issuer App)->>Generic Verifier SAAS (Verifier Service):genericverifier.com/presentations/verify?"ChallengeResponseVP"
              Generic Verifier SAAS (Verifier Service)->>Shipping Co. Website (Issuer App):ackRequest
              Generic Verifier SAAS (Verifier Service)->>Generic Verifier SAAS (Verifier Service):Evaluate Challenge Response
              Generic Verifier SAAS (Verifier Service)->>Shipping Co. Website (Issuer App):shippinco.com/presentations/verified?"VerificationResultVP"
              Shipping Co. Website (Issuer App)->>Generic Verifier SAAS (Verifier Service):ackResponse
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Evaluate business rules
              Shipping Co. Website (Issuer App)->>Shipping Co Database:Register Shiptment info
              Shipping Co Database->>Shipping Co. Website (Issuer App):info registered
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Generate nonce for VP Challenge
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Generate VP Request
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):KirkCallbackURL2?"Request for DID Atuh + Hazmat Info + ShippingCoCallbackURL2"
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):Ack Request
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Evaluate business rules for requested Hazmat Info
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Generate VP containing Hazmat Info
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):ShippingCoCallbackURL2?"HazmatVP + KirkCallbackURL3"
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):Ack Response
              Shipping Co. Website (Issuer App)->>Generic Verifier SAAS (Verifier Service):genericverifier.com/presentations/verify?"HazmatVP"
              Generic Verifier SAAS (Verifier Service)->>Shipping Co. Website (Issuer App):ackRequest
              Generic Verifier SAAS (Verifier Service)->>Generic Verifier SAAS (Verifier Service):Evaluate Hazmat VP
              Generic Verifier SAAS (Verifier Service)->>Shipping Co. Website (Issuer App):shippinco.com/presentations/verified?"VerificationResultVP"
              Shipping Co. Website (Issuer App)->>Generic Verifier SAAS (Verifier Service):askResponse
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Check business rules
              Shipping Co. Website (Issuer App)->>Shipping Co Database:Register Hazmat Info
              Shipping Co Database->>Shipping Co. Website (Issuer App):info registered
              Shipping Co. Website (Issuer App)->>Shipping Co Database:Request Shipment and Hazmat info
              Shipping Co Database->>Shipping Co. Website (Issuer App):requested info
              Shipping Co. Website (Issuer App)->>Shipping Co. Website (Issuer App):Generate BoLRequestVP
              Shipping Co. Website (Issuer App)->>Generic Issuer SAAS (Issuer Service):genericissuer.com/credentials/issue?"BoLRequestVP"
              Generic Issuer SAAS (Issuer Service)->>Shipping Co. Website (Issuer App):ackRequest
              Generic Issuer SAAS (Issuer Service)->>Generic Issuer SAAS (Issuer Service):Check business rules
              Generic Issuer SAAS (Issuer Service)->>Shipping Co. Website (Issuer App):shippingco.com/credentials/issued?"BoL"
              Shipping Co. Website (Issuer App)->>Generic Issuer SAAS (Issuer Service):ackResponse
              Shipping Co. Website (Issuer App)->>Kirk Company Enterprise Resource Planning App (Holder and Holder Service):KirkCallbackURL3?"BoL"
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Shipping Co. Website (Issuer App):Ack Response
              Kirk Company Enterprise Resource Planning App (Holder and Holder Service)->>Ignio (Logistic Manager):BoL Ready notice
            
UC6.3 Mermaid

Contributed by: Digital Bazaar

Author Email: msporny@digitalbazaar.com

Author Github: msporny

Aggregated Credential Workflow

Kenzie is using digital credentials to apply for a job at as a teacher. Her teaching certification is already in her digital wallet but the school also requires a criminal background check for which Kenzie does not currently have a credential. The process of getting the background check can take 24–48 hours. Kenzie goes to the job application website and submits her application; the website responds requesting both her teaching credential and a criminal background check credential --issued by some set of known issuers?-- Some of his credentials are available today, some will need to be provided when they are ready (for example, a criminal background check can take 24-48 hrs to process). He would like these credentials to be presented to the Verifier (service provider) when ready, without having to constantly return to the Verifier (service provider) and deliver them "by hand". He should be able to have them released from his Holder directly as they become available.

Requirements:

Mermaid

              sequenceDiagram
                  autonumber
                      Kenzie (Holder)->>jobapplications.com (Verifier App):jobapplications.com/presenations/submit?"application"
                      jobapplications.com (Verifier App)->>jobapplications.com (Verifier App):process application
                      jobapplications.com (Verifier App)->>Kenzie (Holder):Request credentials A and B
                      Kenzie (Holder)->>Kenzie's Wallet (Holder Service):Check for A and B
                      Kenzie's Wallet (Holder Service)->>Kenzie (Holder):Display A, B not found
                      Kenzie (Holder)->>Kenzie's Wallet (Holder Service):Need B
                      Kenzie's Wallet (Holder Service)->>backgroundcheck.com (Issuer App):backgroundcheck.com/index.html
                      backgroundcheck.com (Issuer App)->>Kenzie's Wallet (Holder Service):index.html
                      Kenzie's Wallet (Holder Service)->>backgroundcheck.com (Issuer App):backgroundcheck.com/getBackgroundCheck
                      backgroundcheck.com (Issuer App)->>Kenzie's Wallet (Holder Service):getBackgoundCheck.html
                      Kenzie's Wallet (Holder Service)->>backgroundcheck.com (Issuer App):backgroundcheck.com/getBackgrounCheck/credentials/issue?"RequestedInfo"
                      backgroundcheck.com (Issuer App)->>backgroundcheck.com (Issuer App):evaluate requested info
                      backgroundcheck.com (Issuer App)->>Generic Issuer (Issuer Service):genericissuer.com/credentials/issue?"backgrounCheckCredential+info"
                      Generic Issuer (Issuer Service)->>backgroundcheck.com (Issuer App):issued VC
                      backgroundcheck.com (Issuer App)->>Kenzie's Wallet (Holder Service):kenzieswallet.com/credentials/recieve?"VC"
                      Kenzie's Wallet (Holder Service)->>Kenzie (Holder):Notify B Ready
                      Kenzie (Holder)->>jobapplications.com (Verifier App):jobapplications.com/presenations/submit?"application"
                      jobapplications.com (Verifier App)->>Kenzie (Holder):Request Credentials A and B
                      Kenzie (Holder)->>Kenzie's Wallet (Holder Service):Send A and B to jobapplications.com
                      Kenzie's Wallet (Holder Service)->>jobapplications.com (Verifier App):jobapplications.com/presentations/submit?"application with A and B"
                      jobapplications.com (Verifier App)->>Generic Verifier (Verifier Service):genericVerifer.com/presentations/verify?"applicationwith A and B"
                      Generic Verifier (Verifier Service)->>jobapplications.com (Verifier App):Verification Result
                      jobapplications.com (Verifier App)->>jobapplications.com (Verifier App):process application
                      jobapplications.com (Verifier App)->>Kenzie's Wallet (Holder Service):Application Accepted
                      Kenzie's Wallet (Holder Service)->>Kenzie (Holder):Application Accepted
            
UC6.4 Mermaid

Contributed by:SecureKey Technologies Inc.

Author Email: mike.varley@securekey.com

Author Github: mavarley

Submit/Sign/Verify a test credential to a licensure system

A student, Shabazz, wants to publish their MBLEx test results from an education test provider, Massage Therapy Test Corp. Massage Therapy Test Corp proxies their authority to sign to a service provider, SSI Ventures. SSI Ventures issues Shabazz a VC when he logs into his Massage Therapy Test Corp account and enables his browser-based SSI Wallet, Billfold. The signed VC is then stored in Shabazz’ Billfold™ Wallet to be presented elsewhere.

In a separate session, Shabazz logs into a web portal of a State Massage Therapy licensure system to apply for his Massage Therapy license. The licensure specialist at the State checks the issuer using a State accreditation system, then checks the signature on the test results VC and ingests the credential’s payload. The licensure specialist then finalizes their workflow and issues Shabazz a Massage Therapy license.

Requirements:

  • 1. VC Issuance
  • 2. VC Presentation
  • 3. Issuer Lookup (is that business logic?),
  • 4. VP Verification
  • 5. VC Verification
  • X. Website as Consumer.
  • X. Issuance-as-a-Service,
  • Mermaid

                sequenceDiagram
                    autonumber
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):massagetherapytestcorp.com
                        Shabazz's Billfold (Holder App - includes browser)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/index.html
                        Massage Therapy Test Corp Webpage (Issuer App)->>Shabazz's Billfold (Holder App - includes browser):index.html
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):display webpage
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Authenticate
                        Shabazz's Billfold (Holder App - includes browser)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/authenticate
                        Massage Therapy Test Corp Webpage (Issuer App)->>Shabazz's Billfold (Holder App - includes browser):authentication challenge
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):challenge
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):authentication information
                        Shabazz's Billfold (Holder App - includes browser)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/authenticate?"info"
                        Massage Therapy Test Corp Webpage (Issuer App)->>Massage Therapy Test Corp Webpage (Issuer App):process authentication information
                        Massage Therapy Test Corp Webpage (Issuer App)->>Shabazz's Billfold (Holder App - includes browser):authentication success
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):authentication success
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):get Message Therapy Credential
                        Shabazz's Billfold (Holder App - includes browser)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/getTherapyCredential
                        Massage Therapy Test Corp Webpage (Issuer App)->>Shabazz's Billfold (Holder App - includes browser):DID Auth Challenge
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Display wallet selector
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Selected Wallet
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Display profile selector
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Selected Profile
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz's Wallet (Holder Service):Request DID Auth Challenge Responsew
                        Shabazz's Wallet (Holder Service)->>Shabazz's Wallet (Holder Service):generate DID Auth response
                        Shabazz's Wallet (Holder Service)->>Shabazz's Billfold (Holder App - includes browser):DID Auth response
                        Shabazz's Billfold (Holder App - includes browser)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/getTherapyCredential/didAuth?"DIDAuthResponse"
                        Massage Therapy Test Corp Webpage (Issuer App)->>Massage Therapy Test Corp Webpage (Issuer App):Process response
                        Massage Therapy Test Corp Webpage (Issuer App)->>SSI Venture (Issuer Service):ssiventures.com/messagetestcorp/credentials/issue?"VPfromDIDAuth"
                        SSI Venture (Issuer Service)->>Massage Therapy Test Corp Webpage (Issuer App):messagetherapytestcorp.com/credentials/issued?"issuedCredentailsWrappedByIssuerApp"
                        Massage Therapy Test Corp Webpage (Issuer App)->>Shabazz's Billfold (Holder App - includes browser):HolderApp/newCredential?"issuedCredentialUnwrappedByIssuerApp"
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz's Wallet (Holder Service):store credential
                        Shabazz's Wallet (Holder Service)->>Shabazz's Billfold (Holder App - includes browser):success
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Credential successfully stored in wallet
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Go to Floyd's Message Therapy Webpage
                        Shabazz's Billfold (Holder App - includes browser)->>floydsmassagetheray.com (Verifier App):floydsmessagetherapy.com/index.html
                        floydsmassagetheray.com (Verifier App)->>Shabazz's Billfold (Holder App - includes browser):index.html
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):display page
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Submit employment application
                        Shabazz's Billfold (Holder App - includes browser)->>floydsmassagetheray.com (Verifier App):floydsmessagetherapy.com/employmentApp
                        floydsmassagetheray.com (Verifier App)->>Shabazz's Billfold (Holder App - includes browser):Domain&Challenge
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Display wallet selector
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):wallet selection
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Display profile selector
                        Shabazz (Holder)->>Shabazz's Billfold (Holder App - includes browser):Selected Profile
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz's Wallet (Holder Service):Domain&Challenge
                        Shabazz's Wallet (Holder Service)->>Shabazz's Wallet (Holder Service):generate VP
                        Shabazz's Wallet (Holder Service)->>Shabazz's Billfold (Holder App - includes browser):Challenge response VP
                        Shabazz's Billfold (Holder App - includes browser)->>floydsmassagetheray.com (Verifier App):floydsmessagetherapy.com/empoymentApp/challengeResponse?"VP"
                        floydsmassagetheray.com (Verifier App)->>floydsmassagetheray.com (Verifier App):Process response
                        floydsmassagetheray.com (Verifier App)->>Shabazz's Billfold (Holder App - includes browser):request application with State License VC
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz's Wallet (Holder Service):Request VP
                        Shabazz's Wallet (Holder Service)->>Shabazz's Wallet (Holder Service):Generate VP
                        Shabazz's Wallet (Holder Service)->>Shabazz's Billfold (Holder App - includes browser):VP w/Application and State License
                        Shabazz's Billfold (Holder App - includes browser)->>floydsmassagetheray.com (Verifier App):floydsmessagetherapy.com/presenatations/submit?"Application wtih State License VP"
                        floydsmassagetheray.com (Verifier App)->>State Verifier (Verifier Service):stateverifier.com/credentials/verify?"StateLicenseVC"
                        State Verifier (Verifier Service)->>floydsmassagetheray.com (Verifier App):Verification Result
                        floydsmassagetheray.com (Verifier App)->>floydsmassagetheray.com (Verifier App):process application
                        floydsmassagetheray.com (Verifier App)->>Shabazz's Billfold (Holder App - includes browser):Application submitted
                        Shabazz's Billfold (Holder App - includes browser)->>Shabazz (Holder):Application submitted
              
    UC6.5 Mermaid

    Contributed by:RANDA Solutions

    Author Email: marty.reed@randasolutions.com

    Author Github: martyr160

    Supply Chain Import

    In order to export steel products to the global market, Steel Mills Global must prove the quality of their products. For this, they rely on Inspectors & Co, an internationally recognized steel testing company. Upon inspection, Inspectors & Co issues a Mill Test Report VC to Steel Mills Global.

    Steel Inc. imports and distributes steel products domestically. Negotiating a shipment Steel Mills Global presents the MTR as proof of product quality. Steel Inc. verifies the MTR VP and accepts the shipment.

    Steel Inc. initiates the importing procedures, starting out self-issuing an Import Declaration Form VC. The MTR and IDF are jointly presented to the Customs authority which verifies the VP. Upon verification the customs release is granted for goods import.

    Note: These VC types are taken from the Traceability Vocabulary, a W3C-CCG work item for supply chain use-cases.

    Requirements:

    Mermaid

                sequenceDiagram
                     autonumber
                        Holder - Steel Mills Global (SMG)->>Holder App -  SMG Enterprise API:getMillTestReportVC     
                        Holder App -  SMG Enterprise API->>Issuer App - Inspectors & Co Enterprise Software:inspectorandco.com/credentials/issue     
                        Issuer App - Inspectors & Co Enterprise Software->>Lacy - Inspectors & Co Inspector:New inspection requested     
                        Lacy - Inspectors & Co Inspector->>Lacy - Inspectors & Co Inspector:Completes SMG Inspection     
                        Lacy - Inspectors & Co Inspector->>Issuer App - Inspectors & Co Enterprise Software:Issue Mill Test Report to SMG     
                        Issuer App - Inspectors & Co Enterprise Software->>Issuer Service - Inspectors & Co Issuer:IandCoIssuer.com/credentials/issue     
                        Issuer Service - Inspectors & Co Issuer->>Issuer Service - Inspectors & Co Issuer:Process request     
                        Issuer Service - Inspectors & Co Issuer->>Issuer App - Inspectors & Co Enterprise Software:Issued Credentials     
                        Issuer App - Inspectors & Co Enterprise Software->>Holder App -  SMG Enterprise API:smgApi.com/credentials/recieve?\"MillTestReportVP\"     
                        Holder App -  SMG Enterprise API->>Holder App -  SMG Enterprise API:Process returned VP     
                        Holder App -  SMG Enterprise API->>Holder Service - SMG Wallet:smgWallet.com/credentials/store?\"MTRVP\"     
                        Holder Service - SMG Wallet->>Holder Storage - SMG EDV/KMS:smgEdv.com/credentials/store?\"MTRVP\"     
                        Holder Storage - SMG EDV/KMS->>Holder Storage - SMG EDV/KMS:Store credentials     
                        Holder Storage - SMG EDV/KMS->>Holder Service - SMG Wallet:Storage success and access info     
                        Holder Service - SMG Wallet->>Holder App -  SMG Enterprise API:Storage acknowledged     
                        Holder App -  SMG Enterprise API->>Holder - Steel Mills Global (SMG):Mill Test Report recieved     
                        Steel Inc->>Holder - Steel Mills Global (SMG):Purchase Inquiry     
                        Holder - Steel Mills Global (SMG)->>Holder - Steel Mills Global (SMG):Process Inquiry    
                        Holder - Steel Mills Global (SMG)->>Steel Inc:Agree to sell     
                        Steel Inc->>Holder - Steel Mills Global (SMG):Request Mill Test Report     
                        Holder - Steel Mills Global (SMG)->>Holder App -  SMG Enterprise API:sendMillTestReportVC     
                        Holder App -  SMG Enterprise API->>Verifier App - Steel Inc. Business API:steelincapi.com/presentations/available     
                        Verifier App - Steel Inc. Business API->>Holder App -  SMG Enterprise API:Domain&Challenge     
                        Holder App -  SMG Enterprise API->>Holder Service - SMG Wallet:smgWallet.com/presentations/issue?\"Domain&Challenge\"     
                        Holder Service - SMG Wallet->>Holder Service - SMG Wallet:Generate VP containing the MTR     
                        Holder Service - SMG Wallet->>Holder Storage - SMG EDV/KMS:smgEdv.com/credentials/sign?\"GeneratedVP\"     
                        Holder Storage - SMG EDV/KMS->>Holder Storage - SMG EDV/KMS:Sign VP     
                        Holder Storage - SMG EDV/KMS->>Holder Service - SMG Wallet:SignedVP     
                        Holder Service - SMG Wallet->>Holder App -  SMG Enterprise API:SignedVP     
                        Holder App -  SMG Enterprise API->>Verifier App - Steel Inc. Business API:steelincapi.com/presentations/submissions?\"SignedVP\"     
                        Verifier App - Steel Inc. Business API->>Verifier App - Steel Inc. Business API:Check business rules     
                        Verifier App - Steel Inc. Business API->>Verifier Service - Steel Industry Verifier:steelindustryverifier.com/presentations/verify     
                        Verifier Service - Steel Industry Verifier->>Verifier Service - Steel Industry Verifier:Check proofs     
                        Verifier Service - Steel Industry Verifier->>Issuer Service - Inspectors & Co Issuer:IandCoIssuer.com/credentials/revocationList?\"MTRVC\"     
                        Issuer Service - Inspectors & Co Issuer->>Issuer Service - Inspectors & Co Issuer:Check revocation list     
                        Issuer Service - Inspectors & Co Issuer->>Verifier Service - Steel Industry Verifier:revocationStatus=notRevoked     
                        Verifier Service - Steel Industry Verifier->>Verifier App - Steel Inc. Business API:steelincapi.com/presentations/verified?\"MTRVC\"     
                        Verifier App - Steel Inc. Business API->>Verifier App - Steel Inc. Business API:Check business rules     
                        Verifier App - Steel Inc. Business API->>Verifier App - Steel Inc. Business API:Record verification result     
                        Verifier App - Steel Inc. Business API->>Steel Inc:New Verification Result Notification     
                        Verifier App - Steel Inc. Business API->>Holder App -  SMG Enterprise API:steelincapi.com/presentations/verified?\"SignedVP\"     
                        Holder App -  SMG Enterprise API->>Holder - Steel Mills Global (SMG):Mill Test Report Verified 
              
    UC6.6 Mermaid

    Contributed by:Transmute Industries

    Author Email: nis@transmute.industries

    Author Github: nissimsan

    Terminology

    This section is non-normative.

    Acknowledgements

    The editors are thankful to the contributions from the VC API Working Group