draft of the proofmode spec

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+# NIP-XX: ProofMode - Cryptographic Video Verification
+
+`draft` `optional`
+
+## Abstract
+
+This NIP defines a standard for attaching cryptographic proof manifests to video events (NIP-71) to enable verification of video authenticity, recording continuity, and device integrity. ProofMode allows viewers to verify that a video was recorded on a specific device at a specific time without editing or tampering.
+
+## Motivation
+
+Social media platforms are increasingly vulnerable to deepfakes, edited videos, and synthetic media. While blockchain timestamping exists, it doesn't prove video continuity or prevent frame-level manipulation. ProofMode solves this by:
+
+1. **Frame-level verification** - SHA256 hashes of captured frames prove recording continuity
+2. **Hardware attestation** - iOS App Attest and Android Play Integrity verify the recording device
+3. **Cryptographic signing** - PGP signatures ensure manifest authenticity
+4. **Tamper detection** - Any edit to the video invalidates the proof chain
+5. **Segment tracking** - Recording pauses are documented with sensor data
+
+## Specification
+
+### Event Tags
+
+ProofMode data is attached to video events (typically Kind 34236) using the following tags:
+
+#### Required Tags
+
+- `["verification", "<level>"]` - Verification level (see Verification Levels below)
+- `["proofmode", "<manifest_json>"]` - Complete ProofManifest as compact JSON
+
+#### Optional Tags
+
+- `["device_attestation", "<token>"]` - Hardware attestation token from iOS App Attest or Android Play Integrity
+- `["pgp_fingerprint", "<fingerprint>"]` - PGP public key fingerprint used to sign the manifest
+
+### Verification Levels
+
+The `verification` tag indicates the strength of cryptographic proof:
+
+- `verified_mobile` - Highest level: has device attestation + PGP signature + complete manifest
+- `verified_web` - Medium level: has PGP signature + complete manifest (no hardware attestation)
+- `basic_proof` - Low level: has proof data but no cryptographic signature
+- `unverified` - No meaningful proof data
+
+### ProofManifest Structure
+
+The `proofmode` tag contains a JSON object with the following structure:
+
+```json
+{
+  "sessionId": "<unique_session_id>",
+  "challengeNonce": "<16_char_nonce>",
+  "vineSessionStart": "<ISO8601_timestamp>",
+  "vineSessionEnd": "<ISO8601_timestamp>",
+  "totalDuration": 6500,
+  "recordingDuration": 6000,
+  "segments": [
+    {
+      "segmentId": "<segment_id>",
+      "startTime": "<ISO8601_timestamp>",
+      "endTime": "<ISO8601_timestamp>",
+      "duration": 3000,
+      "frameHashes": [
+        "<sha256_hash_1>",
+        "<sha256_hash_2>",
+        "..."
+      ],
+      "frameTimestamps": [
+        "<ISO8601_timestamp_1>",
+        "<ISO8601_timestamp_2>",
+        "..."
+      ],
+      "sensorData": {
+        "accelerometer": {"x": 0.1, "y": 0.2, "z": 9.8},
+        "gyroscope": {"x": 0.01, "y": 0.02, "z": 0.01}
+      }
+    }
+  ],
+  "pauseProofs": [
+    {
+      "startTime": "<ISO8601_timestamp>",
+      "endTime": "<ISO8601_timestamp>",
+      "duration": 500,
+      "sensorData": {
+        "timestamp": "<ISO8601_timestamp>",
+        "accelerometer": {"x": 0.1, "y": 0.2, "z": 9.8},
+        "gyroscope": {"x": 0.01, "y": 0.02, "z": 0.01},
+        "magnetometer": {"x": 45.0, "y": 12.0, "z": -30.0},
+        "light": 150.0
+      },
+      "interactions": [
+        {
+          "timestamp": "<ISO8601_timestamp>",
+          "interactionType": "touch",
+          "coordinates": {"x": 180, "y": 640},
+          "pressure": 0.5
+        }
+      ]
+    }
+  ],
+  "interactions": [
+    {
+      "timestamp": "<ISO8601_timestamp>",
+      "interactionType": "start|stop|touch",
+      "coordinates": {"x": 180, "y": 640},
+      "pressure": 0.5,
+      "metadata": {}
+    }
+  ],
+  "finalVideoHash": "<sha256_hash_of_complete_video>",
+  "deviceAttestation": {
+    "token": "<platform_specific_attestation_token>",
+    "platform": "iOS|Android|Web",
+    "deviceId": "<device_identifier>",
+    "isHardwareBacked": true,
+    "createdAt": "<ISO8601_timestamp>",
+    "challenge": "<challenge_nonce>",
+    "metadata": {
+      "attestationType": "app_attest|play_integrity|fallback",
+      "deviceInfo": {
+        "platform": "iOS",
+        "model": "iPhone 15 Pro",
+        "version": "17.0",
+        "manufacturer": "Apple"
+      }
+    }
+  },
+  "pgpSignature": {
+    "signature": "-----BEGIN PGP SIGNATURE-----\n...\n-----END PGP SIGNATURE-----",
+    "publicKey": "-----BEGIN PGP PUBLIC KEY BLOCK-----\n...\n-----END PGP PUBLIC KEY BLOCK-----",
+    "publicKeyFingerprint": "1A2B3C4D5E6F7890..."
+  }
+}
+```
+
+### Field Descriptions
+
+#### Core Fields
+- `sessionId` - Unique identifier for the recording session
+- `challengeNonce` - Random nonce generated at session start, used in device attestation to prevent replay attacks
+- `vineSessionStart` / `vineSessionEnd` - Recording session boundaries
+- `totalDuration` - Total elapsed time in milliseconds (including pauses)
+- `recordingDuration` - Actual recording time in milliseconds (excluding pauses)
+
+#### Segments
+Recording can be paused and resumed, creating multiple segments. Each segment contains:
+- `segmentId` - Unique segment identifier
+- `startTime` / `endTime` - Segment boundaries
+- `frameHashes` - Array of SHA256 hashes of captured video frames
+- `frameTimestamps` - Timestamps when each frame was captured (optional)
+- `sensorData` - Device sensor readings during recording (optional)
+
+#### Pause Proofs
+When recording is paused, sensor data is collected to prove device continuity:
+- `startTime` / `endTime` - Pause boundaries
+- `sensorData` - Sensor readings during pause (accelerometer, gyroscope, magnetometer, light)
+- `interactions` - User touch/tap events during pause
+
+#### Interactions
+User interactions recorded throughout the session:
+- `timestamp` - When interaction occurred
+- `interactionType` - Type of interaction (start, stop, touch)
+- `coordinates` - Screen coordinates of interaction
+- `pressure` - Touch pressure (optional)
+
+#### Final Video Hash
+- `finalVideoHash` - SHA256 hash of the complete rendered video file
+
+#### Device Attestation
+Platform-specific hardware attestation proving the device is genuine:
+- **iOS**: Uses App Attest API (iOS 14+)
+- **Android**: Uses Play Integrity API
+- **Web/Other**: Fallback software attestation
+
+Fields:
+- `token` - Platform-specific attestation token
+- `platform` - Operating system (iOS, Android, Web)
+- `deviceId` - Device identifier
+- `isHardwareBacked` - Whether attestation uses hardware security module
+- `challenge` - Challenge nonce used in attestation (matches `challengeNonce`)
+- `metadata` - Platform-specific attestation details
+
+#### PGP Signature
+Cryptographic signature of the entire manifest:
+- `signature` - PGP signature in ASCII-armored format
+- `publicKey` - PGP public key in ASCII-armored format
+- `publicKeyFingerprint` - Key fingerprint for quick lookup
+
+## Implementation
+
+### Recording Phase
+
+1. **Start Session**
+   - Generate unique `sessionId` and `challengeNonce`
+   - Request hardware device attestation with challenge nonce
+   - Initialize ProofMode session
+
+2. **Capture Frames**
+   - During recording, periodically capture video frames
+   - Generate SHA256 hash of each frame
+   - Store frame hashes with timestamps
+   - Optionally collect sensor data (accelerometer, gyroscope, etc.)
+
+3. **Handle Pauses**
+   - When recording pauses, stop current segment
+   - Begin collecting pause proof data (sensor readings, interactions)
+   - When resuming, start new segment
+
+4. **Finalize Session**
+   - Stop recording and close final segment
+   - Hash complete video file
+   - Compile ProofManifest with all segments, pauses, and interactions
+   - Sign manifest with PGP private key
+   - Attach ProofManifest to video event as tags
+
+### Verification Phase
+
+To verify a ProofMode video, clients should:
+
+1. **Extract ProofManifest**
+   - Parse `proofmode` tag from video event
+   - Extract `deviceAttestation` and `pgpSignature` from separate tags
+
+2. **Verify PGP Signature**
+   - Extract PGP public key from manifest
+   - Verify signature of manifest JSON
+   - Check public key fingerprint matches `pgp_fingerprint` tag
+
+3. **Verify Device Attestation** (if present)
+   - Validate attestation token against platform-specific APIs
+   - Verify challenge nonce matches manifest `challengeNonce`
+   - Check attestation timestamp is recent (within 24 hours of recording)
+
+4. **Verify Frame Hashes** (advanced)
+   - Re-encode video to extract individual frames
+   - Generate SHA256 hashes of extracted frames
+   - Compare against hashes in manifest segments
+   - Verify frame count and timestamps match recording duration
+
+5. **Verify Recording Continuity**
+   - Check that segment timestamps are contiguous
+   - Verify pause durations match gaps between segments
+   - Validate total recording duration matches video length
+
+6. **Display Verification Badge**
+   - `verified_mobile` - Show "Verified" badge with hardware attestation icon
+   - `verified_web` - Show "Signed" badge
+   - `basic_proof` - Show "Basic Proof" indicator
+   - `unverified` - No badge or "Unverified" indicator
+
+## Example Event
+
+```json
+{
+  "kind": 34236,
+  "pubkey": "...",
+  "created_at": 1730326800,
+  "tags": [
+    ["d", "unique-video-identifier"],
+    ["title", "My Verified Video"],
+    ["url", "https://media.example.com/video.mp4", "720x1280"],
+    ["thumb", "https://media.example.com/thumb.jpg", "720x1280"],
+    ["duration", "6"],
+    ["verification", "verified_mobile"],
+    ["proofmode", "{\"sessionId\":\"session_1730326800000_1234\",\"challengeNonce\":\"a1b2c3d4e5f6789\",\"vineSessionStart\":\"2025-10-30T10:00:00.000Z\",\"vineSessionEnd\":\"2025-10-30T10:00:06.500Z\",\"totalDuration\":6500,\"recordingDuration\":6000,\"segments\":[{\"segmentId\":\"segment_1\",\"startTime\":\"2025-10-30T10:00:00.000Z\",\"endTime\":\"2025-10-30T10:00:06.000Z\",\"frameHashes\":[\"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855\"]}],\"pauseProofs\":[],\"interactions\":[{\"timestamp\":\"2025-10-30T10:00:00.000Z\",\"interactionType\":\"start\",\"coordinates\":{\"x\":180,\"y\":640}}],\"finalVideoHash\":\"d4e5f6a7b8c9...\"}"],
+    ["device_attestation", "AAABBBCCC..."],
+    ["pgp_fingerprint", "1A2B3C4D5E6F7890..."]
+  ],
+  "content": "Check out this verified video!",
+  "sig": "..."
+}
+```
+
+## Security Considerations
+
+### Threat Model
+
+ProofMode protects against:
+- ✅ **Post-recording video editing** - Frame hashes detect any modifications
+- ✅ **Deepfakes and synthetic videos** - Hardware attestation proves real device
+- ✅ **Timestamp manipulation** - Device attestation includes trusted timestamps
+- ✅ **Replay attacks** - Challenge nonce prevents reuse of attestations
+
+ProofMode does NOT protect against:
+- ❌ **Screen recording** - A user can screen-record another video
+- ❌ **Camera lens manipulation** - Physical objects placed in front of camera
+- ❌ **Compromised devices** - Rooted/jailbroken devices may forge attestations
+- ❌ **Social engineering** - User can intentionally create misleading content
+
+### Privacy Considerations
+
+- **Device Identifiers**: The `deviceId` field may be sensitive. Clients should:
+  - Hash or truncate device IDs before publishing
+  - Allow users to opt-out of device attestation
+  - Clearly indicate when ProofMode is active
+
+- **Sensor Data**: Accelerometer and gyroscope data may reveal user location or behavior. Clients should:
+  - Allow disabling sensor data collection
+  - Sanitize or omit sensitive sensor readings
+  - Aggregate sensor data to reduce precision
+
+- **PGP Keys**: Users should be able to:
+  - Rotate PGP keys periodically
+  - Revoke compromised keys
+  - Use separate keys for different purposes
+
+### Verification Best Practices
+
+Verifying clients should:
+
+1. **Always check PGP signature** - This is the minimum verification
+2. **Validate device attestation** when present - But gracefully handle missing/invalid attestations
+3. **Display verification level prominently** - Users should understand confidence level
+4. **Cache verification results** - Re-verification is expensive
+5. **Handle expired attestations** - Attestations may expire after 24-48 hours
+6. **Warn on missing proofs** - But don't assume malice if ProofMode is absent
+
+## Reference Implementation
+
+OpenVine provides a complete reference implementation:
+- **Recording**: `ProofModeSessionService` in OpenVine mobile app
+- **Publishing**: `VideoEventPublisher` adds ProofMode tags to Nostr events
+- **Verification**: `ProofModeHelpers` and verification UI components
+
+Source: https://github.com/openvine/openvine
+
+## Backwards Compatibility
+
+This NIP is fully backwards compatible:
+- Events without ProofMode tags are treated as unverified
+- Older clients ignore ProofMode tags
+- ProofMode is opt-in - videos without it still work normally
+
+## Future Extensions
+
+Possible future enhancements:
+
+1. **Witness Signatures** - Multiple devices co-sign the same recording
+2. **Location Proofs** - GPS coordinates with cryptographic verification
+3. **Biometric Proof** - Prove human presence during recording
+4. **Chain of Custody** - Track video transfer and handling
+5. **Selective Disclosure** - Zero-knowledge proofs for privacy-preserving verification
+
+## References
+
+- [NIP-01: Basic protocol flow description](https://github.com/nostr-protocol/nips/blob/master/01.md)
+- [NIP-71: Video Events](https://github.com/nostr-protocol/nips/blob/master/71.md)
+- [iOS App Attest](https://developer.apple.com/documentation/devicecheck/establishing_your_app_s_integrity)
+- [Android Play Integrity](https://developer.android.com/google/play/integrity)
+- [ProofMode Original Project](https://proofmode.org)
+
+## Authors
+
+- Evan Henshaw-Plath (Rabble) - Divine.Video Project
+
+## License
+
+This NIP is released into the public domain.
+