---
id: "hardman-sentries-confessionals-vaults-and-envelopes"
type: "paper"
type_label: "Papers and paper collections"
title: "Sentries, Confessionals, Vaults, and Envelopes"
maintainer: "Daniel Hardman"
authors:
  - "Daniel Hardman"
date: "2023-01-18"
year: 2023
reading_level: "intro"
reading_level_label: "Introductory"
reading_level_meaning: "no prior knowledge of the suite"
evidence: "informative"
evidence_meaning: "an author's paper, deck, tutorial or post explaining the suite"
status: "quiet"
status_meaning: "no change in six to eighteen months; still correct"
access: "public"
access_meaning: "anyone with the link"
topics:
  - "theory"
  - "comparisons"
roles:
  - "communications"
  - "researcher"
source_url: "https://dhh1128.github.io/papers/svce.html"
source_license: null
source_license_note: null
found_on: "hardman-papers"
kerisse_credit: false
abstract_license: "CC BY 4.0"
abstract_license_url: "https://creativecommons.org/licenses/by/4.0/"
abstract_attribution: "KSKB, the KERISuite Knowledge Base (https://kskb.dev/)"
last_checked: "2026-10-15"
kskb_url: "https://kskb.dev/cards/hardman-sentries-confessionals-vaults-and-envelopes/"
kskb_app_url: "https://kskb.dev/#item/hardman-sentries-confessionals-vaults-and-envelopes"
kskb_record_url: "https://kskb.dev/data/kskb/resources/hardman-sentries-confessionals-vaults-and-envelopes"
kskb_markdown_url: "https://kskb.dev/export/cards/hardman-sentries-confessionals-vaults-and-envelopes.md"
---

# Sentries, Confessionals, Vaults, and Envelopes

A 2023 primer by Daniel Hardman that uses a medieval metaphor to distinguish four decentralized identity technologies often treated as rivals: OpenID Connect (OIDC), the Credential Handler API (CHAPI), Decentralized Web Nodes (DWNs) and DIDComm. It argues that they solve different problems and that interoperability work should draw boundaries between them rather than unify them. For people working in self-sovereign identity (SSI) and adjacent standards.

Labels: reading level Introductory; evidence informative (an author's paper, deck, tutorial or post explaining the suite).
Source: https://dhh1128.github.io/papers/svce.html (license not recorded).
The abstract is KSKB's own text under Creative Commons Attribution 4.0 (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/; credit KSKB, the KERISuite Knowledge Base (https://kskb.dev/).