Observation Commitment Protocol (OCP) v1.0.0

Cryptography
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Observation Commitment Protocol (OCP) v1.0.0

A minimal primitive for committing arbitrary data digests to a public ledger

Summary

This post introduces the Observation Commitment Protocol (OCP) — a minimal, ledger-relative primitive for:

  • Committing a cryptographic digest of arbitrary data to a public ledger
  • Producing a portable proof of that commitment
  • Verifying that proof under explicit assumptions

OCP isolates the smallest possible interface for:

data → digest → ledger → verification

It deliberately avoids introducing assumptions about storage, identity, data availability, or application-layer semantics.

Motivation

There is no widely adopted primitive for:

  • Committing arbitrary data digests to a ledger
  • Producing portable, independently verifiable proofs of those commitments
  • Verifying such proofs without reliance on trusted infrastructure

Existing approaches are typically:

  • Application-specific
  • Coupled to storage or data availability layers (e.g., IPFS, DA systems)
  • Bundled with identity or signature schemes
  • Dependent on canonical encoding formats

OCP separates these concerns and defines only what is strictly necessary for verifiable inclusion of a digest in a ledger.

Core Idea

OCP defines the following invariant:

A proof is accepted if and only if:

  • H = hash(observation)
  • H ∈ R(tx) where tx is the transaction referenced by the proof

No additional meaning is implied.

Model

Parties

  • Prover — constructs commitments and produces proofs
  • Verifier — evaluates proofs relative to a verification context

Verification Context

Verification is defined relative to:

  • A ledger view L
  • A hash function hash
  • An encoding and extraction rule R

Proofs are not self-describing; correctness depends on agreement on this context.

In particular, the verifier must apply the same rule R used to produce the commitment.

Proof Structure

A proof is defined as:

P = (observation, H, tx_ref)

Where:

  • H = hash(observation)
  • tx_ref identifies a transaction in L

Verification Function

Verify(P, L, hash, R) → {0,1}

Verification succeeds if and only if:

  1. hash(observation) = H
  2. tx_ref resolves to a transaction tx ∈ L
  3. H ∈ R(tx)

This defines a minimal, deterministic, stateless verification procedure.

Security Intuition

An adversary succeeds if it produces a proof P* such that:

  • observation* ≠ observation
  • Verify(P*, L, hash, R) = 1

This requires either:

  • Breaking collision or preimage resistance of the hash function, or
  • Causing the verifier to accept an incorrect ledger view

Properties

  • Minimal commitment primitive
  • Explicit verification assumptions
  • Ledger-relative correctness
  • No trusted intermediaries
  • Offline verifiability (given access to L)
  • Composable with higher-level systems

Non-Goals

OCP does not define:

  • Data availability
  • Identity or authorship
  • Signature schemes
  • Canonical encoding standards
  • Application-layer semantics

Why This Might Matter

OCP can be viewed as a missing primitive:

A standardized way to bind arbitrary data to a ledger and verify that binding independently.

Potential applications include:

  • AI and data provenance
  • Scientific logging
  • Sensor networks
  • Media authenticity
  • Cross-system audit trails
  • Dispute evidence systems

Adversarial Framing

The protocol is intentionally falsifiable.

Given a valid (observation, proof) pair:

  • Modify the observation in any way
  • Attempt to produce a proof that still verifies

If this succeeds under the same (L, hash, R) context, the protocol is broken.

Repository

Includes:

  • Canonical specification (v1.0.0)
  • Reference implementation
  • Example proofs and verification flows
  • End-to-end submission and verification tooling

Specification

Request for Feedback

Looking for feedback on:

  • Whether this primitive already exists in a cleaner or more standard form
  • Ambiguities in the definition of R (encoding and extraction rule)
  • Ledger model assumptions (e.g., reorgs, weak subjectivity)
  • Whether this abstraction belongs at the protocol layer or application layer
  • Any overlooked attack surfaces

Closing Thought

OCP makes a narrow claim:

It does not establish what data means.
It establishes that a specific digest was included in a ledger.

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OCP — Example + Clarification

This section provides a concrete example to clarify how OCP operates in practice.

Example

Let:

  • observation = "hello world"
  • H = hash(observation)

A transaction tx is constructed such that:

  • H is included in the transaction (e.g., calldata or event log)

Define an encoding and extraction rule R such that:

  • R(tx) returns a set of extracted 32-byte values from the transaction

A proof is then:

P = (observation, H, tx_ref)

Verification

A verifier performs:

  1. Compute:
    H' = hash(observation)

  2. Check:
    H' == H

  3. Resolve:
    tx from tx_ref

  4. Extract:
    S = R(tx)

  5. Check:
    H ∈ S

If all checks pass → Verify = 1

Important Clarification

OCP does not prove:

  • Who created the data
  • When the data was created in real-world time
  • That the data is true, valid, or meaningful

OCP proves only:

  • That a specific digest H was included in a ledger

What is Actually Being Proven?

Not:

“this file is authentic”

But:

“this exact byte sequence hashes to H, and H exists in the ledger”

Why This Matters

Even the smallest change to observation:

  • produces a completely different hash H*
  • which will not match the committed H

Therefore:

  • verification must fail

This is the core integrity guarantee.

Minimal Mental Model

OCP is:

  • Not storage
  • Not identity
  • Not truth

It is:

A binding between bytes and a ledger