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)wheretxis 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_refidentifies a transaction inL
Verification Function
Verify(P, L, hash, R) → {0,1}
Verification succeeds if and only if:
hash(observation) = Htx_refresolves to a transactiontx ∈ LH ∈ R(tx)
This defines a minimal, deterministic, stateless verification procedure.
Security Intuition
An adversary succeeds if it produces a proof P* such that:
observation* ≠ observationVerify(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.