Hacker News new | ask | show | jobs
by DennisP 1684 days ago
Here's one of Ethereum's lead researchers talking about the attacks in that paper. The fixes are simple and not expected to delay the merge.

https://blog.ethereum.org/2021/11/02/finalized-no-31/

1 comments

Written for public consumption that post conveys a great deal of certainty while eliding over doubts:

"Change fork choice rule to mitigate balancing and reorging attacks"

https://ethresear.ch/t/change-fork-choice-rule-to-mitigate-b...

And more fundamentally at the heart of the matter

https://ethresear.ch/t/comment-on-three-attacks-on-proof-of-...

> Moreover, there is a general argument that the attacker will always be able to keep the consensus from finalizing nomatter what the fix is.

> The argument simply comes from the fact, that mathematically provable binary consensus algorithms known in this universe have n2 behavior, and ETH2 is linear in n .

> Therefore, the only way to really fix ETH2 is to make it n2 . Otherwise it is unfixable from the math point of view. There will always be another attack.

> It may be that by continuing patching a fix after a fix after a fix one can end up with something that will work from an engineering point of view.

> This will be security by obscurity.

> But it will not be secure from the math point of view.

So while bodging in patches might work one day, it's an immature approach and a scary place to try store value.

The sheer number of moving parts create a scary amount of emergent complexity and complexity is the enemy of security.

Disclosure: I'm an early but now uncomfortable ETH holder.

On the "fundamental" link, see this reply that appeared after you commented:

"The reason that Ethereum’s consensus can run in n time rather than n^2 is BLS signature aggregation. The attacks in the paper however aren’t attacks on signature aggregation. So I don’t think your argument is valid."

> mathematically provable binary consensus algorithms known in this universe have n^2 behavior

Is there a convenient way for an uneducated schmuck like me to read up on this? Just a comment without references isn't much to go on.