• Cryptpad Subsumation — Kapnet Document Protocol
  • The Thesis
  • Feature Mapping
  • Document as Sheet TXXM
    • Properties
  • Collaborative Editing Flow
  • Encryption Model
    • Room-Level Encryption (Exo)
    • Content-Level Encryption (Endo)
    • Dual Encryption
  • Permission Model
  • Version History
  • Real-Time Synchronization
    • Push Model (Nostr Subscription)
    • Conflict Resolution (Braid Ordering)
    • Offline Support
  • Implementation Path
    • Phase 1: Basic Document (Mac Mini)
    • Phase 2: Encryption (Mac Mini + White Noise)
    • Phase 3: Advanced Features
  • Comparison: Kapnet Documents vs Cryptpad
  • Action Items

§Cryptpad Subsumation — Kapnet Document Protocol

§The Thesis

Cryptpad is a collaborative office suite: end-to-end encrypted, open-source, real-time collaborative editing.

Kapnet subsumes Cryptpad entirely. Every Cryptpad feature maps to a Kapnet primitive. We don’t integrate Cryptpad — we absorb it.

§Feature Mapping

§Document as Sheet TXXM

A “document” in Kapnet is a Sheet TXXM with a specific schema:

Sheet TXXM:
  sheet_id: "doc-unique-id"
  name: "Document Title"
  columns: [seq, timestamp, author, operation, content, hash, prev_hash]
  rows: [...]

Row (Edit) TXXM:
  seq: 42
  timestamp: 1717500000
  author: npub1...
  operation: insert|delete|update|format
  content: "The text that was edited"
  hash: sha256:abc...
  prev_hash: sha256:def... (previous row)

§Properties

• Append-only: Edits are new rows, never modify existing rows
• Hash-chained: Each row references previous row’s hash
• Author-signed: Each row signed by editor’s npub
• Namespace-scoped: Document belongs to a KOR namespace
• Encrypted: Sheet encrypted via MLS group key (White Noise room)

§Collaborative Editing Flow

USER A                          KAPNET                         USER B
   │                               │                               │
   ├─ Compose edit ────────────────┼───────────────────────────────┤
   │                               │                               │
   ├─ Sign TXXM (npub) ───────────┼───────────────────────────────┤
   │                               │                               │
   ├─ Encrypt (MLS group key) ────┼───────────────────────────────┤
   │                               │                               │
   ├─ Publish to relay ───────────►│                               │
   │                               ├─ Validate TXXM ───────────────┤
   │                               ├─ Update braid ────────────────┤
   │                               ├─ Update state tree ───────────┤
   │                               ├─ Push to subscribers ─────────┤
   │                               │                               │
   │                               ├─ Relay ───────────────────────►│
   │                               │                               │
   │                               │         Decrypt (MLS) ◄───────┤
   │                               │         Apply edit ◄──────────┤
   │                               │         Update view ◄─────────┤

§Encryption Model

§Room-Level Encryption (Exo)

• Each document room = White Noise group
• MLS group key encrypts all TXXMs in the room
• Forward secrecy: past edits safe even if key compromised
• Post-compromise security: future edits safe after key rotation

§Content-Level Encryption (Endo)

• Each TXXM payload can be individually encrypted
• Only authorized KOR members can decrypt
• Auth level determines read/write permissions

§Dual Encryption

TXXM PAYLOAD (Endo encryption)
  └── Encrypted with KOR scope key
      └── Only AUTH-3+ can decrypt

TXXM ENVELOPE (Exo encryption)
  └── Encrypted with MLS group key
      └── Only room members can receive

§Permission Model

§Version History

Every edit is a row in the sheet. The braid preserves ALL versions:

Row 1: [seq=1, op=insert, content="Hello", author=A, prev=genesis]
Row 2: [seq=2, op=insert, content=" World", author=B, prev=row1]
Row 3: [seq=3, op=update, content="Hello World!", author=A, prev=row2]
Row 4: [seq=4, op=delete, content="!", author=C, prev=row3]
...

To reconstruct document at any point:

1. Start from genesis row
2. Apply each row in sequence
3. Stop at desired row

The hash chain ensures tamper detection. Any modification to history breaks the chain.

§Real-Time Synchronization

§Push Model (Nostr Subscription)

• Clients subscribe to relay for document updates
• New TXXMs pushed via WebSocket
• No polling needed

§Conflict Resolution (Braid Ordering)

• Concurrent edits → braid captures both
• Deterministic ordering (weakwork score → timestamp → hash)
• No “last writer wins” — both edits preserved
• Users see both versions, choose which to keep

§Offline Support

• Edits queued locally when offline
• Sync when reconnected
• Braid resolves conflicts automatically

§Implementation Path

§Phase 1: Basic Document (Mac Mini)

1. Implement Sheet TXXM schema
2. Implement row append (edit submission)
3. Implement hash chain verification
4. Implement Nostr push sync

§Phase 2: Encryption (Mac Mini + White Noise)

1. Integrate White Noise MLS for room encryption
2. Implement KOR scope for permissions
3. Implement dual encryption (endo + exo)

§Phase 3: Advanced Features

1. Rich text editing (Markdown → TXXM)
2. Media attachments (blob TXXM)
3. Comments (review TXXM linked to parent)
4. Export (TXXM → PDF/Markdown/HTML)
5. Search (state tree query)

§Comparison: Kapnet Documents vs Cryptpad

§Action Items

1. Design Sheet TXXM schema (columns, row format)
2. Implement edit submission (TXXM append)
3. Implement hash chain verification
4. Integrate White Noise MLS for room encryption
5. Build web UI (TXXM → HTML rendering)
6. Test real-time sync (Nostr subscription)
7. Test conflict resolution (braid ordering)