Bitcoin as an Interplanetary Monetary Standard with Proof-of-Transit Timestamping (2508.20591v1)

Abstract: We explore the feasibility of deploying Bitcoin as the shared monetary standard between Earth and Mars, accounting for physical constraints of interplanetary communication. We introduce a novel primitive, Proof-of-Transit Timestamping (PoTT), to provide cryptographic, tamper-evident audit trails for Bitcoin data across high-latency, intermittently-connected links. Leveraging Delay/Disruption-Tolerant Networking (DTN) and optical low-Earth-orbit (LEO) mesh constellations, we propose an architecture for header-first replication, long-horizon Lightning channels with planetary watchtowers, and secure settlement through federated sidechains or blind-merge-mined (BMM) commit chains. We formalize PoTT, analyze its security model, and show how it measurably improves reliability and accountability without altering Bitcoin consensus or its monetary base. Near-term deployments favor strong federations for local settlement; longer-term, blind-merge-mined commit chains (if adopted) provide an alternative. The Earth L1 monetary base remains unchanged, while Mars can operate a pegged commit chain or strong federation with 1:1 pegged assets for local block production. For transparency, if both time-beacon regimes are simultaneously compromised, PoTT-M2 (and PoTT generally) reduces to administrative assertions rather than cryptographic time-anchoring.

• The paper introduces Proof-of-Transit Timestamping (PoTT) as a transport-level primitive that secures interplanetary Bitcoin transactions by chaining cryptographic receipts through relay nodes.
• It integrates header-first replication, latency-aware Lightning policies, and asynchronous settlement rails to manage OWLT challenges and ensure cross-planetary payment verification.
• The architecture preserves Bitcoin’s base consensus while employing multi-relay security and tamper-evident mechanisms for dispute resolution in interplanetary networks.

Bitcoin as an Interplanetary Monetary Standard: Proof-of-Transit Timestamping

Introduction and Motivation

The paper presents a comprehensive architecture for deploying Bitcoin as a monetary standard across interplanetary domains, specifically focusing on the Earth–Mars regime. The central challenge addressed is the physical constraint imposed by the one-way light time (OWLT), which ranges from 3 to 22 minutes between Earth and Mars, and the resulting impossibility of synchronous mining or real-time settlement. The authors propose a layered solution that preserves Bitcoin’s base-layer parameters and consensus, while introducing new primitives and operational policies at higher layers to enable reliable verification, payments, and dispute resolution across astronomical distances.

Proof-of-Transit Timestamping (PoTT): Design and Formalization

A key contribution is the introduction of Proof-of-Transit Timestamping (PoTT), a transport-level receipt primitive that cryptographically chains hop-timed custody attestations to Bitcoin payload hashes. Each relay node in the Delay/Disruption-Tolerant Networking (DTN) path appends a signed receipt containing ingress/egress timestamps (encoded in TAI seconds), a unique per-message nonce, and a hash binding to the previous hop. The resulting chain-of-custody is splice-resistant and provides tamper-evident evidence of message propagation, suitable for Lightning Network disputes and sidechain peg operations.

Figure 1: PoTT flow: each relay appends a signed receipt, forming a verifiable chain-of-custody for dispute evidence and sidechain pegs.

The PoTT wire format is specified as canonical CBOR, with strict field definitions and signature scope. The design leverages BIP340 Schnorr signatures and mandates administrative diversity and independent time-beacon audits for high-assurance verification profiles (e.g., PoTT-M2). The inclusion of a per-message nonce and anti-splice hash chain prevents replay and path-forging attacks.

Interplanetary Bitcoin Architecture

The proposed architecture comprises three coordinated layers:

1. Header-First Replication: Gateways and relays prioritize block headers for timely fork choice and MTP anchoring, minimizing bandwidth requirements ($\sim$4.2 MB/year for headers).
2. Latency-Aware Lightning Policy: Lightning channels and HTLCs are parameterized with additional CLTV/CSV margins derived from OWLT and jitter allowances. The closed-form expression for the incremental margin is:

$$\Delta^{\mathrm{extra}_{\mathrm{CLTV}}} = \left\lceil \frac{\mathrm{RTT} + J}{b_{\text{target}}} \right\rceil$$

where $\mathrm{RTT} = 2 \cdot \mathrm{OWLT}$ and $b_{\text{target}}$ is the L1 block interval.

Figure 2: Incremental Lightning CLTV margin as a function of interplanetary latency and jitter allowance.

1. Asynchronous Settlement Rails: Cross-domain settlement is achieved via strong federations or blind-merge-mined (BMM) commit chains, with PoTT evidence required for peg-in/out bundles. Mars operates a pegged commit chain or federation with 1:1 pegged assets, while Earth retains the unchanged Bitcoin L1 monetary base.

   Figure 3: Conceptual architecture: DTN deep-space links carry BPv7 bundles with PoTT receipts; each planetary domain runs its own Bitcoin/Lightning network; asynchronous settlement via federations or BMM sidechains.

Integration with Existing Protocols

PoTT is designed to be strictly out-of-band, attaching receipts in transport metadata without altering Bitcoin consensus or BOLT wire formats. Bitcoin full-node validation remains unchanged; PoTT chains are consumed by watchtowers, Lightning nodes, and sidechain federations for enhanced operational accountability and dispute resolution.

Figure 4: Stack integration: PoTT receipts are attached in transport metadata at every relay; Lightning/watchtowers and settlement rails consume receipts; full-node validation is unaffected.

Security Analysis and Verification Profiles

The security model assumes unbroken cryptographic primitives, availability of signed time beacons, and at least one honest relay per verified path. PoTT provides integrity, authenticity, and monotonic ordering of custody claims, but does not guarantee liveness or censorship-resistance. The PoTT-M2 verification profile requires at least three relays from two distinct administrative domains, with independent time-beacon anchors and consistency with OWLT envelopes.

The authors highlight that if all relays and time-beacons are compromised, PoTT evidence degrades to administrative assertions. For high-stakes disputes, multipath diversity and independent anchors are mandated. Privacy is addressed via onion encryption and commit-and-reveal protocols, minimizing metadata leakage except during disputes.

Operational Considerations

Key management is handled via hardware-backed keys, periodic rotation, and DNSSEC-anchored allowlists. Time synchronization leverages GNSS, deep-space two-way transfer, and CCSDS time-code formats, with operational margins adjusted during beacon degradation. PoTT chains are retained for at least 90 days, and phased deployment is outlined from terrestrial testbeds to Mars surface networks.

Theoretical and Practical Implications

The architecture demonstrates that synchronous, cross-planet competitive mining is infeasible at current Bitcoin parameters, but a Bitcoin-based interplanetary economy is achievable via asynchronous settlement and latency-aware policies. The separation of concerns preserves the monetary base and validation model, while higher layers internalize the costs of distance and provide explicit policy knobs for safety and accountability.

The authors provide a heuristic bound showing that base-layer block intervals would need to scale to hour-level durations to preserve fairness across planets, which would severely penalize throughput. Instead, adaptation is shifted to transport receipts and L2/L3 protocols.

Limitations and Future Directions

PoTT does not provide liveness or censorship-resistance; its assurance is contingent on the integrity of cryptography and time-beacons. The architecture does not attempt to equalize miner fairness across planets at L1, accepting temporarily segmented fee markets and FX-like spreads during periods of limited connectivity.

Future work includes formal security proofs for PoTT, interoperable specifications and reference implementations, and end-to-end testbeds emulating AU-scale RTT and blackout conditions.

Conclusion

The paper presents a physics-aware, incrementally deployable architecture for interplanetary Bitcoin, centered on Proof-of-Transit Timestamping (PoTT) as an accountability layer for delay-tolerant operation. By combining header-first replication, latency-aware Lightning policies, and asynchronous settlement rails, the design enables reliable verification, payments, and dispute resolution across planetary domains without altering Bitcoin consensus. The approach is robust, modular, and compatible with existing standards, providing a concrete path toward a shared monetary standard for a multi-planetary civilization.