Use Cases for SPICE

Internet-Draft	sd-cwt	March 2024
Prorock & Zundel	Expires 4 September 2024	[Page]

Abstract

This document describes various use cases related to credential exchange in a three party model (issuer, holder, verifier). These use cases aid in the identification of which Secure Patterns for Internet CrEdentials (SPICE) are most in need of specification or detailed documentation.¶

Status of This Memo

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This Internet-Draft will expire on 4 September 2024.¶

Copyright Notice

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2. Introduction

There is a need to more clearly document verifiable credentials - that is credentials that utilize the issuer, holder, and verifier (three party) model across various work IETF, ISO, W3C, and other SDOs. This need particularly arises in use cases for verifiable credentials that do not involve human-in-the-loop interactions, need strong identifiers for business entities, and for those that require CBOR encoding, and those that leverage the cryptographic agility properties of COSE. This document which covers multiple use cases for verifiable credentials will help inform both the required architecture and components, as well as to help frame needs for any clearly defined message formats and/or supporting mechanisms.¶

3. SPICE Common Patterns

Within SPICE there are a few common patterns that continually arise:¶

A need for selective disclosure with CBOR based verifiable credentials¶
Cryptographic agility support via COSE, including support for PQC, and to permit use of the same signature algorithms with both selective disclosure as well as fully disclosed credentials¶
Required strong and long lived identities that are correlated with public key material for verifiacation and permit binding to DNS, existing x509 certificates, as well as providing ready access to public keys for verification utilizing HTTP¶

4. SPICE Use Cases

There are several expanding use cases and common patterns that motivate the working group and broader community, including:¶

Use of microcredentials, particularly in education¶
Digitization of physical supply chain credentials in multiple jurisdictions¶
- CBOR credentials¶
- High volume with system to system exchange of credentions¶
- both regulatory data as well as business driven information¶
IoT, Control Systems, and Critical Infrastructure related Credentials¶
Credentials related to authenticity and provenance, especially of digital media¶
Offline exchange (in person) of credentials that may have been internet issued¶
Embedding of credentials in other data formats¶
Digital Wallet Initiatives¶

5. Use Case Discussion

5.1. Roles

An "issuer", an entity (person, device, organization, or software agent) that constructs and secures digital credentials.¶

A "holder", an entity (person, device, organization, or software agent) that controls the disclosure of credentials.¶

A "verifier", an entity (person, device, organization, or software agent) that verifies and validates secured digital credentials.¶

5.2. Physical Supply Chain Credentials

Physical supply chain credentials create several unique scenarios and requirements for technical implementers. There is a strong movement towards digitiztion of physical supply chain data which is often exchanged in paper or scanned pdf form today using legacy approaches. Some steps have been taken towards digitatization of supply chain data in XML, however the steps have proved problematic over native binary formats due to the complexity, size, and volumes of transmission often involved.¶

Common use cases for physical supply chains include:¶

Regulatory data capture and exchange with governmental bodies¶
Requirements around capturing specific types of data including:¶
- Inspection information¶
- Permits¶
- Compliance certification (both regulatory and private)¶
- Traceability information, including change of control and geospatial coordinates¶
Providing the ability for 3rd parties to "certify" information about another actor in the supply chain. e.g. Vendor A is an approved supplier for Company X¶
Passing of data between multiple intermediaries, before being sent along to customs agencies or consignees.¶
Moving large amounts of signed data asyncronously, and bi-directionally over a network channel¶
Identifying actors in a supply chain and linking them with legal entity information¶

5.4. Others

TBD¶

Use Cases for SPICE

Abstract

Status of This Memo

Copyright Notice

Table of Contents

1. Notational Conventions

2. Introduction

3. SPICE Common Patterns

4. SPICE Use Cases

5. Use Case Discussion

5.1. Roles

5.2. Physical Supply Chain Credentials

5.4. Others

6. Security Considerations

7. IANA Considerations

8. Acknowledgements

9. Normative References

Authors' Addresses