Trust DID Web - A DID Method

The spec repository for did:tdw -- Trust DID Web DID method.

Read the spec: https://identity.foundation/trustdidweb

Proof of concept implementations available:

• Typescript: https://github.com/bcgov/trustdidweb-ts
• Python: https://github.com/bcgov/trustdidweb-py
• Go: https://github.com/nuts-foundation/trustdidweb-go

Abstract

The did:tdw (Trust DID Web) method is an enhancement to the did:web protocol, providing a complementary web-based DID method that addresses limitations of did:web. It's features include the following.

• Ongoing publishing of all DID Document (DIDDoc) versions for a DID instead of, or alongside a did:web DID/DIDDoc.
• Uses the same DID-to-HTTPS transformation as did:web.
• Provides resolvers the full history of the DID using a verifiable chain of updates to the DIDDoc from genesis to deactivation.
• A self-certifying identifier (SCID) for the DID that is globally unique and derived from the initial DIDDoc that enables DID portability, such as moving the DIDs web location (and so the DID string itself) while retaining the DID's history.
• DIDDoc updates include a proof signed by the DID Controller(s) authorized to update the DID.
• An optional mechanism for publishing "pre-rotation" keys to prevent loss of control of the DID in cases where an active private key is compromised.
• An optional mechanism for having collaborating "witnesses" that approve updates to the DID by the DID Controller before publication.
• DID URL path handling that defaults (but can be overridden) to automatically resolving <did>/path/to/file by using a comparable DID-to-HTTPS translation as for the DIDDoc.
• A DID URL path <did>/whois that defaults to automatically returning (if published by the DID controller) a Verifiable Presentation containing Verifiable Credentials with the DID as the credentialSubject, signed by the DID.

Combined, the additional features enable greater trust and security without compromising the simplicity of did:web. The incorporation of the DID Core compatible "/whois" path, drawing inspiration from the traditional WHOIS protocol, offers an easy to use, decentralized, trust registry. This did:tdw aims to establish a more trusted and secure web environment by providing robust verification processes and enabling transparency and authenticity in the management of decentralized digital identities.

Contributing to the Specification

Pull requests (PRs) to this repository may be accepted. Each commit of a PR must have a DCO (Developer Certificate of Origin - https://github.com/apps/dco) sign-off. This can be done from the command line by adding the -s (lower case) option on the git commit command (e.g., git commit -s -m "Comment about the commit").

Rendering and reviewing the spec locally for testing requires npm and node installed. Follow these steps:

• Fork and locally clone the repository.
• Install node and npm.
• Run npm install from the root of your local repository.
• Edit the spec documents (in the /spec folder).
• Run npm run render'
  • Use npm run edit to interactively edit, render and review the spec.
• Review the resulting index.html file in a browser.

The specification is currently in Spec-Up format. See the Spec-Up Documentation for a list of Spec-Up features and functionality.

Publishing Previous Spec Versions

Spec-Up allows for multiple versions of the spec to be rendered and accessed on the same site. We use that feature for the did:tdw spec to snapshot previous versions of the spec for reference.

To create a snapshot of a version:

• Make a new folder in the root of the repository for the new version, called spec-v<ver>. For example v0.3.
• Copy the spec folder markdown files from the point of that version into the new folder. If you are doing this process as you are starting a new version, you can just copy the files from the spec folder of the main branch. Otherwise, you have to find the last commit of the version and get the files from that point in the GitHub history.
• Update the specs.json file to include a new specification:
  • Copy the primary spec entry text.
  • Paste that text into a new spec entry in the "specs" array.
  • Update the "spec_directory" property to be the name of the new folder you created.
  • Update the "output_path" property to be ./v<ver>. For example "./v0.3".
  • Append to the "title" property the version - Version <ver>, For example - Version 0.3.
• Add a link to the versioned specification in the Previous Drafts bullet list, in the header.md file in the main spec, so that readers can click on it from the main specification.
• Update the header.md file of the new version spec folder (e.g in spec-v0.3) to:
  • Change the status to HISTORICAL -- **THIS IS NOT THE CURRENT VERSION OF THE SPECIFICATION**
  • As appropriate, add guidance for readers WITHOUT altering the version of the specification itself.
  • Remove the Past Drafts section and put a relative link back to the current spec -- such as:

**Latest Version:**

- Specification: [https://identity.foundation/trustdidweb/](../)
- Repository: [https://github.com/decentralized-identity/trustdidweb](https://github.com/decentralized-identity/trustdidweb)

Handling Version Transitions

In the lifecycle of the specification, there will be times when the version is stable, but clarifications may be added, and when new versions are being defined with breaking changes. We use the Spec-Up feature to have multiple versions (described above) to enable that, but it gets a little tricky. Notably, we want the landing page for the specification to always be the current version of the specification, and we want all "in progress" work to be to made to the single, primary specification (the files in the spec folder), so that GitHub holds the full evolution of the specification. To enable that, we adjust as needed the "output_path" in the specs.json file to define what version of the spec is on the specification landing page -- the spec version whose "output_path" is set to "./").

Here's how we do that:

• When the specification is stable, the spec folder is the landing page, and past versions are linked in the header.md file as "past versions".
• When a new version of the specification with breaking changes is ready to be worked on:
  • Snapshot the stable specification version by creating a new directory (e.g., spec-v0.4) and copying the files from the spec folder into the new folder
  • Create a new entry in the specs.json file for the version.
  • Set the output_path of the new version (e.g., spec-v0.4) to be "./", so that it becomes the landing page.
  • Change the output_path of the primary spec folder entry to "./next".
  • Update the header.json files in both the new folder and the spec folder to link to one another, adding any notes to help readers understand the status of the current and next versions of the specification.
• When the "next" version of the specification stabilizes, revert to the "normal" state of the spec folder being the landing page.
  • Change the output_path of the primary spec folder to "./".
  • Change the output_path of the formerly "current" spec version to a path that includes its version (e.g., "./v0.4").
  • Update the header.json files in both the (now past version) folder and the spec folder to link to one another's new output_path values, remove any clarification notes that no longer apply, and make the past version "just another" past version (e.g., like spec-v0.3)