Local Sync

Physical proximity is the ultimate encryption. Local sync lets devices sync directly over your local network—no internet, no cloud, no interception possible.

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What is Local Sync?

Local sync is Skelenote's peer-to-peer network sync system. When enabled:

1. Your device advertises itself on the local network

2. Other Skelenote devices with the same Skeleton Key are discovered

3. Data syncs directly between devices over TCP

4. All traffic stays on your local network

No internet required. No relay servers. No data exposure.

This is the Privacy Air-Gap: the only way to share data that nobody can intercept is to never send it over the internet at all.

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How Discovery Works

mDNS/Bonjour

Skelenote uses mDNS (multicast DNS) to advertise and discover peers on your local network:

• Service type: _skelenote._tcp.local.

• Automatic discovery: Devices appear within seconds of joining the network

• No configuration needed: Works on any local network (WiFi, Ethernet, VPN)

TXT Record Metadata

Each device advertises:

Field	Description
fp	Key fingerprint (for peer filtering)
id	Device ID
name	Human-readable device name
v	Protocol version

Peer Filtering

Only devices with matching key fingerprints can discover each other:

• Fingerprint is derived from your Skeleton Key

• Different keys = different fingerprints = invisible to each other

• Revoked devices are blocked even with matching fingerprints

This means a coffee shop full of Skelenote users won't see each other's devices—only devices sharing the same Skeleton Key appear.

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Setting Up Local sync

Prerequisites

• Two or more devices with Skelenote installed

• Same Skeleton Key configured on all devices

• Devices on the same local network (WiFi, LAN, or VPN)

Steps

1. Open Settings > Sync > Local sync

2. Toggle Enable Local sync on

3. Your device will appear in the "Discovered Devices" list on other devices

4. Sync happens automatically when devices connect

Verifying Connection

Indicator	Meaning
Green dot	Connected and syncing
Yellow dot	Discovered, connecting
Device list	Shows last sync time for each device

Changes propagate within seconds on a typical local network.

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QR Code Pairing

Why QR Pairing?

While mDNS discovery works automatically on most networks, some environments make it difficult:

• Mobile devices may not support mDNS reliably

• Corporate networks often block multicast traffic

• VPN configurations can interfere with local discovery

• Complex network setups with multiple subnets or VLANs

QR code pairing solves these problems by encoding connection information directly. Point, scan, connect—no network configuration required.

Generating a QR Code (Desktop)

1. Open Settings > Devices

2. Click Show Pairing QR

3. A QR code appears on screen

4. The QR code remains valid for 5 minutes

The QR code contains your device's connection information, encrypted so that only devices with your Skeleton Key can read it.

Scanning a QR Code (Mobile)

1. Open Settings > Devices on your mobile device

2. Tap the QR scanner icon (camera icon next to "Add Device")

3. Point your camera at the QR code on the other device

4. Connection establishes automatically

Once paired, devices remember each other and reconnect automatically when on the same network.

What the QR Contains

The QR code encodes:

Field	Purpose
Device IP address	Where to connect
TCP port	Which port to use
Device ID	Unique identifier
Device name	Human-readable name
Protocol version	Ensures compatibility

All fields are encrypted with a key derived from your Skeleton Key. The QR code is useless to anyone who does not have your Skeleton Key.

QR Security

QR pairing maintains Skelenote's zero-knowledge security model:

• Encrypted payload: QR data is encrypted with XChaCha20-Poly1305

• Key-bound: Only devices with your Skeleton Key can decrypt the QR

• Time-limited: QR codes expire after 5 minutes

• No secrets exposed: Even if photographed, the QR reveals nothing without your Skeleton Key

Scenario: You display a pairing QR at a coffee shop. Someone photographs it. They cannot extract any useful information—the encrypted payload requires your Skeleton Key to decrypt.

QR Pairing Troubleshooting

Camera not working:

• Check that Skelenote has camera permissions in your device settings

• On iOS: Settings > Skelenote > Camera

• On Android: Settings > Apps > Skelenote > Permissions > Camera

QR code not scanning:

• Ensure adequate lighting on the QR code

• Hold the camera steady at reading distance (6-12 inches)

• Clean your camera lens

• Try regenerating the QR code on the source device

"QR Expired" error:

• QR codes are valid for 5 minutes

• Generate a fresh QR code and try again

"Connection Failed" after scanning:

• Verify both devices are on the same network

• Check that the source device is still running Skelenote

• Ensure no firewall is blocking the connection

• Try disabling VPN on both devices temporarily

"Invalid QR Code" error:

• Ensure you are scanning a Skelenote pairing QR, not another app's QR

• Verify both devices have the same Skeleton Key configured

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Security Guarantees

Why Proximity = Security

Layer	Protection
Physical	Data never leaves your building/network
Discovery	Only matching Skeleton Keys can discover each other
Transport	XChaCha20-Poly1305 encryption on all data
Authentication	Key fingerprint verification
Revocation	Cryptographically signed device blocklist

The Air-Gap Advantage

When you sync via Local sync:

• No DNS lookups to external servers

• No TCP connections outside your network

• No possibility of internet interception

• Traffic is encrypted even locally (defense in depth)

Even if someone is monitoring your local network, they see only encrypted packets that they cannot decrypt without your Skeleton Key.

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Use Cases

Team Meetings

Sync meeting notes with everyone in the room. When the meeting ends, everyone has the complete record—without ever touching a cloud server.

Scenario: Your team gathers for a strategy session. One person takes notes in Skelenote. By the end of the meeting, everyone's devices have the notes. No cloud, no shared drives, no permissions to configure.

Shared Workspaces

Offices, co-working spaces, or studios can maintain shared knowledge bases that never leave the building.

Scenario: A law firm keeps case research in Skelenote. Attorneys sync their devices over the office network. Client-privileged information never traverses the internet.

Sensitive Environments

Legal offices, medical facilities, or any environment where data must not leave the premises.

Scenario: A hospital uses Skelenote for internal documentation. HIPAA compliance is simplified because PHI never leaves the hospital network.

Untrusted Networks

Hotel WiFi, conference networks, or any public network becomes safer because data only syncs locally.

Scenario: You're at a conference with your laptop and phone on the hotel WiFi. Local sync syncs your devices directly. Even if the hotel network is compromised, your data is encrypted end-to-end and never leaves the local network.

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Troubleshooting

Devices Not Discovering Each Other

1. Verify same Skeleton Key on all devices

2. Check network: Devices must be on the same subnet

3. Firewall: Ensure mDNS (UDP 5353) and Skelenote TCP port are allowed

4. Try toggling: Turn Local sync off and on

5. VPN interference: Some VPNs block local network traffic

Sync Not Working

1. Check device status in Settings > Devices—ensure device is not revoked

2. Verify encryption key matches (same Skeleton Key on both devices)

3. Network restrictions: Some corporate networks block peer-to-peer traffic

4. Restart devices: Close and reopen Skelenote on both devices

Slow Sync

1. Large vault: Initial sync of a large vault takes longer

2. Network congestion: Other traffic on the network may slow sync

3. WiFi quality: Poor signal strength affects sync speed

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Local sync vs Courier

Aspect	Local sync	Courier
Internet required	No	Yes
Data leaves network	No	Yes (encrypted)
Works globally	No	Yes
Maximum security	Yes	Very high
Requires relay server	No	Yes
Sync speed	Fast (local)	Depends on internet
Setup complexity	None	Minimal

Choose Local sync when:

• Security is paramount

• Devices are physically proximate

• You don't want any data on the internet

Choose Courier when:

• You need sync across cities/countries

• Devices are rarely on the same network

• Convenience outweighs maximum security

You can use both: Local sync for local sync when available, Courier for remote devices.

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Further Reading

• Security & Privacy Deep Dive — Full encryption architecture

• Courier Setup — Configure relay server sync