---
id: "hardman-acdcs-and-w3c-vcs-lossless-vs-lossy"
type: "paper"
type_label: "Papers and paper collections"
title: "ACDCs and W3C VCs: Lossless vs. Lossy"
maintainer: "Daniel Hardman"
authors:
  - "Daniel Hardman"
date: "2025-11-24"
year: 2025
reading_level: "practitioner"
reading_level_label: "Practitioner"
reading_level_meaning: "architects, product people and adopters who know identity systems"
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:
  - "comparisons"
  - "theory"
roles:
  - "security-architect"
  - "communications"
  - "researcher"
source_url: "https://dhh1128.github.io/papers/acdc-vc-diff.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-acdcs-and-w3c-vcs-lossless-vs-lossy/"
kskb_app_url: "https://kskb.dev/#item/hardman-acdcs-and-w3c-vcs-lossless-vs-lossy"
kskb_record_url: "https://kskb.dev/data/kskb/resources/hardman-acdcs-and-w3c-vcs-lossless-vs-lossy"
kskb_markdown_url: "https://kskb.dev/export/cards/hardman-acdcs-and-w3c-vcs-lossless-vs-lossy.md"
---

# ACDCs and W3C VCs: Lossless vs. Lossy

An article by Daniel Hardman comparing Authentic Chained Data Containers (ACDCs) with the W3C Verifiable Credentials (VC) data model through an analogy to lossless and lossy media formats. It names six kinds of information it says VCs discard and ACDCs keep, describes where lossy formats fit, and cites the vLEI system and the Verifiable Voice Protocol as production uses. For architects choosing a credential format.

Labels: reading level Practitioner; evidence informative (an author's paper, deck, tutorial or post explaining the suite).
Source: https://dhh1128.github.io/papers/acdc-vc-diff.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/).