---
id: "hardman-zooko-and-houdini-a-flatland-parable"
type: "paper"
type_label: "Papers and paper collections"
title: "Zooko and Houdini: A Flatland Parable"
maintainer: "Daniel Hardman"
authors:
  - "Daniel Hardman"
date: "2024-06-20"
year: 2024
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"
roles:
  - "researcher"
source_url: "https://dhh1128.github.io/papers/zh.html"
source_license: null
source_license_note: null
found_on: "hardman-papers"
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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-zooko-and-houdini-a-flatland-parable/"
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---

# Zooko and Houdini: A Flatland Parable

A primer by Daniel Hardman that uses a Flatland parable to argue that Zooko's triangle (an identifier can be at most two of secure, decentralized and human-friendly) dissolves once human-friendliness is treated as local to each user, like entries in an address book. It recommends discovering identifiers through attributes people choose and resolving to secure, decentralized identifiers when a protocol runs. For readers thinking about identifier naming and usability.

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