---
id: "hardman-analysis-of-did-cel-heartbeat-relevance-to-keri"
type: "paper"
type_label: "Papers and paper collections"
title: "Analysis of did:cel Heartbeat: Relevance to KERI"
maintainer: "Daniel Hardman"
authors:
  - "Daniel Hardman"
date: "2025-12-20"
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/heartbeat-and-witnesses.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-analysis-of-did-cel-heartbeat-relevance-to-keri/"
kskb_app_url: "https://kskb.dev/#item/hardman-analysis-of-did-cel-heartbeat-relevance-to-keri"
kskb_record_url: "https://kskb.dev/data/kskb/resources/hardman-analysis-of-did-cel-heartbeat-relevance-to-keri"
kskb_markdown_url: "https://kskb.dev/export/cards/hardman-analysis-of-did-cel-heartbeat-relevance-to-keri.md"
---

# Analysis of did:cel Heartbeat: Relevance to KERI

A short 2025 analysis by Daniel Hardman of the heartbeat mechanism in the did:cel DID method, a periodic controller signature against retrograde (history-rewriting) attacks, and of whether KERI needs one. It concludes that KERI's pre-rotation and witness-based duplicity detection already cover the threat while allowing cold, offline keys. It is for readers comparing DID methods with KERI.

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