Static Channel Backup (SCB)

A Static Channel Backup is a small file (typically called channel.backup in LND) that captures the minimum metadata needed to recover a Lightning node's on-chain funds after total local data loss: channel funding outpoints, remote node pubkeys, and basic peer-connection info.

It's a "static" backup because the file doesn't need updating after every channel state change. It captures what's needed for emergency recovery, not the current channel balance.

How recovery works with an SCB:

1. Your node dies. Hardware failure, ransomware, dropped phone in the ocean. Local channel state is gone.
2. You install a fresh node, restore the seed phrase, and load the SCB.
3. The new node reaches out to each channel peer with a channel_reestablish message that essentially says "I lost state, please force-close at the latest commitment you have."
4. The peer obliges, broadcasting their latest commitment transaction.
5. Your on-chain funds become spendable after the CSV timelock window expires.

What you give up:

• In-flight HTLCs. Any pending payment routed through your node at the moment of failure may resolve in the counterparty's favor.
• The cheating-detection ability. If your peer is dishonest and broadcasts an older commitment that pays them more, you can't detect or punish it. Watchtowers running before the failure can still respond on your behalf if they were monitoring.
• Channel continuity. Channels close. You start fresh, pay on-chain fees, and re-establish liquidity.

What you keep: your on-chain Bitcoin from the channels' final settled balances. Better than nothing, dramatically better than complete fund loss.

SCBs are an emergency tool, not a substitute for proper backups. The right architecture is: regular volume-level backups of the node's full state directory, plus an up-to-date SCB as a last-resort fallback. Both LND and Core Lightning expose SCB-style recovery; modern Lightning wallets often handle SCB storage automatically.