Dongle Detection

Necron Vault Manager automatically monitors for USB dongle connections. This page explains how detection works, what happens when you plug in or remove a dongle, and how to troubleshoot detection issues.

How Detection Works

The dongle detection system has three layers, working together to ensure your dongle is always recognized promptly:

1. Startup Scan

When the application launches, it performs an immediate scan of all connected USB volumes. This means:

• Your dongle is detected as soon as the app opens — no waiting for background processes
• The dongle status card in the sidebar displays your dongle immediately

2. Automatic Monitoring

On Windows, the app listens for operating system-level notifications whenever a USB volume is added or removed. Benefits:

• Real-time detection — the app knows about USB changes within seconds
• No polling — zero CPU usage when no USB events are occurring

3. Manual Scan

You can trigger a rescan at any time by clicking the dongle status card in the sidebar. This rescans all mounted volumes for Necron key files and updates the dongle list.

What Happens When You Plug In a Dongle

When a USB volume containing a valid Necron key file is detected:

1. Volume detected — the operating system notifies the app
2. Key validated — the app checks the USB drive for a valid Necron key file
3. UI updated — the sidebar shows the new dongle with its name, role (MASTER/SLAVE), and a green status indicator
4. Vault sessions updated — if the dongle was previously connected and had vault sessions, those sessions may be restored

The entire process typically takes under 2 seconds.

What Happens When You Remove a Dongle

When a USB volume is removed:

1. Removal detected — the operating system notifies the app
2. Vault sessions invalidated — for security, any vault unlock sessions tied to the removed dongle are immediately invalidated
3. UI updated — the dongle card shows a disconnected state

Software Key Detection

The software key (Free tier) is detected differently — it's not on a USB volume but stored locally:

• Activated when you log in through the Gatekeeper's "Enter Free Tier" form
• Appears in the dongle status card in the sidebar
• Behaves identically to a hardware dongle for all operations
• Not affected by USB events

Troubleshooting Detection Issues

Dongle Not Detected

If your dongle isn't showing up:

1. Check the USB connection — try a different USB port
2. Verify the drive is mounted — open File Explorer and confirm the drive appears with a drive letter
3. Manual rescan — click the dongle status card in the sidebar to trigger a manual scan
4. Check the key file — ensure the key file on the dongle hasn't been corrupted or accidentally deleted
5. Restart the app — close and reopen Necron Vault Manager, which performs a fresh startup scan

Dongle Detected but Shows Errors

If the dongle appears but shows warnings:

• "Key UID mismatch" — you may have the wrong dongle inserted for the files you're trying to decrypt
• "Corrupt header" — the key file may be damaged. Try the dongle on another computer to verify
• "Read error" — the USB connection may be intermittent. Try a different port

Multiple Dongles

Necron Vault Manager supports multiple dongles connected simultaneously. Each dongle appears as a separate card in the sidebar. The app automatically selects the correct dongle for decryption based on which key was used to encrypt each file.