Timechain: Bitcoin-Anchored Memory
for Humans, Agents, and Institutions

Timechain is a Bitcoin-anchored personal and institutional memory layer. It extends Bitcoin's immutable ledger from financial transactions to all categories of human and organizational truth: past reflections, present focus, future commitments, corporate audit trails, and sovereign AI actions.

This paper describes the technical architecture, the three-mode time model (Past | Present | Future), the Sovereign Agent protocol, the Nostr-based public discovery registry, and the enterprise integration framework.

Generative AI has made it trivially cheap to fabricate any image, voice, document, or memory. The result is an epistemic crisis: the substrate of trust itself is broken. When any record can be retroactively altered, timestamps become worthless. Institutions cannot verify their own audit trails. Individuals cannot prove their own histories.

Existing solutions — centralized databases, notaries, PKI, blockchain-based NFTs — all fail in the same way: they depend on a custodian. The custodian can be corrupted, subpoenaed, shut down, or hacked. The proof vanishes with the custodian.

Bitcoin solves this for money. Timechain solves this for everything else.

Layer 0 — Bitcoin: The anchor substrate. Every Timechain proof is committed to a Bitcoin transaction output via OpenTimestamps (RFC draft). Bitcoin's proof-of-work makes rewriting a confirmed anchor computationally infeasible.

Layer 1 — Anchor Protocol: SHA-256 hash of content + metadata is submitted to the OpenTimestamps calendar. A calendar receipt (upgrade token) is returned immediately; the full Bitcoin proof is generated at the next mined block. Both receipts are stored on-chain (Timechain DB) and off-chain (user download).

Layer 2 — Moment Types: Memory (past), Focus (present — unsearchable by design), Commitment (future), Reflection (today's truth about past events), Corporate (organizational events), Agent (sovereign AI actions).

Layer 3 — Soul Identity: Each user/organization/agent has a deterministic SoulID derived from their public key. SoulIDs are themselves anchored at creation (Origin Anchor). All moments in a timeline are cryptographically linked to one SoulID.

All moments are classified into one of three temporal modes. This is not metadata — it is enforced at the protocol level.

PAST: Reflections, memories, healed events. Searchable, sharable, verifiable. Reflection Anchors allow users to anchor today's truth about past events with a 'ghost date' linking them visually to the original timeline position.

PRESENT (Focus): Active sessions in progress. Unsearchable by design — a sovereign right to be fully present without being recorded in real time. The Focus Block timer runs locally. Only the completed session is anchored.

FUTURE: Commitments, intentions, vows. Signed by one or more parties. Breach conditions specified in plain text. Expiry and amendment anchors supported.

Sovereign Agents are AI actors with their own Timechain identity (Origin Anchor), capability manifest, and kill-switch. Every agent action is an anchored moment with attribution. Agents cannot act on PRESENT-mode data without explicit user grant.

Agent creation: generates keypair → Origin Anchor → published to Nostr registry with capability manifest.

Kill-switch: anchored revocation event. Once anchored, the revocation is permanent and verifiable by any party. The agent's public key is invalidated in all future discovery queries.

Discovery: agents query the Nostr public registry (Kind 30078) to find compatible Timechains. Connection requests are themselves anchored moments.

The public registry uses Nostr protocol (Kind 30078 — application-specific addressable events). No central server. Any relay can serve the registry. Any client can publish.

A Timechain announcement event contains: { pubkey, endpoint, capabilities: ['fleet', 'video', 'calendar', ...], tier, created_at }. The event is signed with the SoulID key and the Nostr event ID is itself anchored to Bitcoin via OpenTimestamps.

Sovereign agents subscribe to any Nostr relay carrying Kind 30078 events. They filter by capability, tier, and geography. Discovery is real-time, permissionless, and censorship-resistant.

Enterprise scenario: A logistics company publishes 'fleet tracking + 200 vehicles + GPS API endpoint'. Fleet Guardian agents worldwide discover it within seconds. The company approves a connection. The approval is anchored.

REST API: POST /v1/anchor accepts any JSON payload, computes SHA-256, returns block_height + ots_receipt. Rate limits per tier. Batch anchoring supported.

Webhooks: Register any URL to receive anchor confirmations. Signed HMAC payload. Retry with exponential backoff.

Pre-built connectors: Google Calendar, GPS/telematics streams, AWS S3 (video frames), Slack (decision audit trail), GitHub (code deploys).

Compliance exports: generate verifiable proof bundles (ZIP containing: original data, SHA-256, OTS proof, block header) for any regulatory framework.

Content privacy: all moment text is encrypted at rest with the user's derived key. The Bitcoin anchor only commits the hash — no plaintext ever leaves the client unencrypted.

Hash collision resistance: SHA-256 is used throughout. No known practical attacks. NIST-approved.

Timestamp precision: Bitcoin block timestamps have ~10 minute granularity. For higher precision, the device timestamp is included in the hashed payload, providing client-side sub-second precision alongside the immutable block anchor.

Threat model: an adversary who wishes to forge an anchor must either (a) find a SHA-256 collision — computationally infeasible — or (b) rewrite the Bitcoin blockchain — requiring 51% of global hashrate for the duration since the anchor block. Both are effectively impossible.