Blockchain

Shared ledger and source truth

A shared ledger orders and replicates data according to rules; it does not automatically make an entry true.

Back to track

Objectives

Distinguish replication from truthfulness.
Identify the source and validation rules.

Duration: 8 min
Level: Foundational

Prerequisites

Sources and limitations

Concepts

Shared ledger
Participants retain a state according to a shared protocol.
Consensus
A mechanism for agreeing on order or state under the network’s rules.
Source truth
The truthfulness of an external entry requires evidence suited to the fact and does not follow from consensus.
Fingerprint anchoring
Anchoring a fingerprint may link data to a commitment recorded under stated rules; it proves neither the data’s truth, author, nor quality.

Visual guide

Before drawing a conclusion

Identify the source.
Separate the anchored fingerprint from source data.
Read the admission rule.
Understand consensus.
Retain the external limitations.

Synthetic example

A ledger faithfully replicates an incorrect statement submitted by an unverified source.

Ledger integrity and the truth of an entry are two distinct properties.

Lesson scope

This lesson explains the conceptual distinction between a ledger, consensus, and input data.

What this lesson does not demonstrate

It confirms no transaction, finality, source, security property, or suitability of a real network.

Check question

What can a shared ledger establish without external evidence?

That every recorded item is true.

That a state or order was accepted under the observed network rules.

That every entry is legally valid.

Choose an answer to read its feedback.

Guided local activity

Ledger or source?

A value appears in a block, but its external source is undocumented. Choose the bounded conclusion.

No real network or block is queried.

Local checklist

Two columns

Separate the ledger fact from the external fact.

No real chain data is used.

Sources and limitations

Source repository: https://github.com/SwissTokint/swisstokint-website
Source reference: codex/learning-hub-v3-autonomous-controls
Content commit: 29c88f79cee07a72804bc017b92fab9200fd3734
Source version: learning-v3

Blockchain Technology OverviewNISTIR-8202
Publisher
National Institute of Standards and Technology (NIST)
Version or date
2018-10
Link verified on
2026-08-13
Scope used
Overview of ledgers, blocks, consensus, and common limitations.
Limitation
The report proves neither source truth, legality, nor universal need.