<blockquote>
<p>Lightning is great but one can't say it is battle-tested. If script
kids would be interested, they could take down those shiny new 5 BTC
wumbo channels with negligible cost and no effort at all.</p>
<p>The underlying issue is that a channel cannot hold more than 483 HTLCs
at a time, regardless of the channel capacity. Sending 483
micro-payments to yourself and holding on to the HTLCs is enough to
incapacitate a channel for up to two weeks.</p>
<p>By utilizing the max route length to add loops, each payment can
consume up to 9 HTLC slots on the target channel. If the script kid is
lucky, they only need to send 54 payments to get it done. A single
tiny channel takes double-digit amounts of Bitcoin out of business.</p>
<p>Below is me locking up approximately 5,800,000 satoshis with a
refundable 18 satoshi payment looping five times through three mainnet
channels owned by Bitfinex and OpenNode. For basically as long as I
want. This happened today.</p>
</blockquote>
<p><a href="https://i.sstatic.net/ssfwn.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ssfwn.jpg" alt="Joost locking up sats" /></a></p>
<blockquote>
<p>Wanting to become the world's payment system sounds good but we can't
have trivially exploitable vulnerabilities like this. Walk the talk.</p>
<p>Therefore I started a new project called <a href="https://github.com/lightningequipment/circuitbreaker" rel="nofollow noreferrer">Circuit Breaker</a>: a
firewall for Lightning nodes. The primary goal is to encourage
thinking about this problem with the potential to grow into a
full-fledged Lightning protection system.</p>
</blockquote>
<p><a href="https://i.sstatic.net/tfAkL.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/tfAkL.png" alt="joost debug output" /></a></p>
<p>This question was answered by Joost Jager on <a href="https://twitter.com/joostjgr/status/1308414364911841281?s=20" rel="nofollow noreferrer">Twitter</a>.</p>

CC BY-SA 4.0
2020-09-23T09:18:58.973Z
2020-09-23T16:14:25.687Z
2020-09-23T16:14:25.687Z
Michael Folkson
<p>Has the Lightning Network reached a level of security and maturity where I can open <a href="https://lightning.engineering/posts/2020-08-20-lnd-v0.11/" rel="nofollow noreferrer">wumbo channels</a> (channels over the previous 0.1677 BTC limit) and be reasonably confident that I won't lose funds or have my funds locked up for long periods?</p>

CC BY-SA 4.0
2020-09-24T19:56:41.270Z
I think this is an interesting post, beyond just wumbo channels. Opening a larger value channel makes the security/reliability consideration more pertinent, but it is still a consideration in any case. Which is to say, I think editing the question to be generalized to *all* lightning channels might be worthwhile, but I'll leave that to OP's consideration.
chytrik
<security><lightning-network>
Is the Lightning Network sufficiently secure and well tested for wumbo channels?
Michael Folkson
# Is the Lightning Network sufficiently secure and well tested for wumbo channels?

(Asked by: username_0 on 2020-09-23)

Has the Lightning Network reached a level of security and maturity where I can open [wumbo channels](https://lightning.engineering/posts/2020-08-20-lnd-v0.11/) (channels over the previous 0.1677 BTC limit) and be reasonably confident that I won't lose funds or have my funds locked up for long periods?

**Tags:** security, lightning-network

> **Comments:**
> **username_1**: I think this is an interesting post, beyond just wumbo channels. Opening a larger value channel makes the security/reliability consideration more pertinent, but it is still a consideration in any case. Which is to say, I think editing the question to be generalized to *all* lightning channels might be worthwhile, but I'll leave that to OP's consideration.  

---

## 1 answers

### Answer by username_0 on 2020-09-23. Score: 3 | Accepted answer

> Lightning is great but one can't say it is battle-tested. If script
> kids would be interested, they could take down those shiny new 5 BTC
> wumbo channels with negligible cost and no effort at all.
>
> The underlying issue is that a channel cannot hold more than 483 HTLCs
> at a time, regardless of the channel capacity. Sending 483
> micro-payments to yourself and holding on to the HTLCs is enough to
> incapacitate a channel for up to two weeks.
>
> By utilizing the max route length to add loops, each payment can
> consume up to 9 HTLC slots on the target channel. If the script kid is
> lucky, they only need to send 54 payments to get it done. A single
> tiny channel takes double-digit amounts of Bitcoin out of business.
>
> Below is me locking up approximately 5,800,000 satoshis with a
> refundable 18 satoshi payment looping five times through three mainnet
> channels owned by Bitfinex and OpenNode. For basically as long as I
> want. This happened today.

[![Joost locking up sats](https://i.sstatic.net/ssfwn.jpg)](https://i.sstatic.net/ssfwn.jpg)

> Wanting to become the world's payment system sounds good but we can't
> have trivially exploitable vulnerabilities like this. Walk the talk.
>
> Therefore I started a new project called [Circuit Breaker](https://github.com/lightningequipment/circuitbreaker): a
> firewall for Lightning nodes. The primary goal is to encourage
> thinking about this problem with the potential to grow into a
> full-fledged Lightning protection system.

[![joost debug output](https://i.sstatic.net/tfAkL.png)](https://i.sstatic.net/tfAkL.png)

This question was answered by Joost Jager on [Twitter](https://twitter.com/joostjgr/status/1308414364911841281?s=20).


---

