<p>Nothing.</p>
<p>If you have lost the last state and are recovering it from your peer then <strong>you are trusting it</strong>, no matter if it's encrypted or not.</p>
<p>They could lie and continue operating (or close) from a state of the channel in which they had a higher balance, or could serve you an encrypted backup for a revoked state and trick you into force-closing to steal your funds through the penalty transaction.</p>

CC BY-SA 4.0
2021-06-03T15:33:59.080Z
2024-09-23T19:53:20.233Z
2024-09-23T19:53:20.233Z
Antoine Poinsot
<p>The fact that the data is encrypted with a key derived from your seed. So the peer cannot use that data it can only back it up for you. After you recover you will need to request that data and decrypt it yourself</p>

CC BY-SA 4.0
2021-06-03T13:50:54.877Z
That's right, the peer cannot use the backup data to close the channel in my name. But the question was, can the peer send me an old backup and therefore trick me into closing the channel using an old state, allowing them to claim all the funds?
Vojtěch Strnad
CC BY-SA 4.0
2021-06-03T20:46:52.830Z
Oh sorry misread that. I think that is actually a pretty valid concern your question raises. I guess a (not optimal) solution would be to have backups with several peers and compare them
Rene Pickhardt
CC BY-SA 4.0
2021-06-03T13:45:10.230Z
2021-06-03T13:45:10.230Z
Rene Pickhardt
<p>Phoenix wallet is a unique Lightning wallet in that, among other things, it allows the user to restore channels by simply entering their seed. According to ACINQ's <a href="https://medium.com/@ACINQ/phoenix-wallet-part-3-backup-f63a9470d4e7" rel="nofollow noreferrer">blogpost</a>, this is how they achieve it:</p>
<blockquote>
<p>TL; DR: Each time channels are updated, Phoenix sends an encrypted version of their data to its peer. This allows for easy backup/restore of channels while maintaining privacy.</p>
</blockquote>
<p>In the case of Phoenix wallet, the peer is always ACINQ, but my question applies to any similar peer backup solutions: what's to stop the peer from making me recover an old channel state, and claim all my funds when I try to close it?</p>

<lightning-network><security><phoenix><lightning-service-provider>
Can ACINQ (Phoenix wallet peer) steal my funds during a recovery?
Vojtěch Strnad
# Can ACINQ (Phoenix wallet peer) steal my funds during a recovery?

(Asked by: username_0 on 2021-06-03)

Phoenix wallet is a unique Lightning wallet in that, among other things, it allows the user to restore channels by simply entering their seed. According to ACINQ's [blogpost](https://medium.com/@ACINQ/phoenix-wallet-part-3-backup-f63a9470d4e7), this is how they achieve it:

> TL; DR: Each time channels are updated, Phoenix sends an encrypted version of their data to its peer. This allows for easy backup/restore of channels while maintaining privacy.

In the case of Phoenix wallet, the peer is always ACINQ, but my question applies to any similar peer backup solutions: what's to stop the peer from making me recover an old channel state, and claim all my funds when I try to close it?

**Tags:** lightning-network, security, phoenix, lightning-service-provider


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## 2 answers

### Answer by username_1 on 2021-06-03. Score: 3 | Accepted answer

Nothing.

If you have lost the last state and are recovering it from your peer then **you are trusting it**, no matter if it's encrypted or not.

They could lie and continue operating (or close) from a state of the channel in which they had a higher balance, or could serve you an encrypted backup for a revoked state and trick you into force-closing to steal your funds through the penalty transaction.


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### Answer by username_2 on 2021-06-03. Score: 0

The fact that the data is encrypted with a key derived from your seed. So the peer cannot use that data it can only back it up for you. After you recover you will need to request that data and decrypt it yourself

> **Comments:**
> **username_0**: That's right, the peer cannot use the backup data to close the channel in my name. But the question was, can the peer send me an old backup and therefore trick me into closing the channel using an old state, allowing them to claim all the funds?  
> **username_2**: Oh sorry misread that. I think that is actually a pretty valid concern your question raises. I guess a (not optimal) solution would be to have backups with several peers and compare them  

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