fascinating and informative talk. highly recommend to listen if you want to learn more about Ethereum.
My short summary:
a) In Ethereum, smart contracts must execute calls to other contracts within a 'single transaction'. A transaction can be rolled back or committed.
b) if an engineer of contract missed a step a call,
but a transaction is committed, there is no way to reverse/cancel it.
c) In this specific case a person executed steps in a transaction, but missed one of the steps.
That step was to 'retrieve' the money due to him/her from another exchange contract, after sending to it some valuable tokens.
d) so the money were not retrieved (I think worth 12K USD).
e) On Ethereum, it is possible to execute steps, ahead of another user, if you offered to pay more 'gas'.
Meaning that somebody could call the 'retrieve money' from a contract, if they paid more 'gas' for that call, and if you failed to execute 'retrieve money' from within
a transaction you started earlier.
f) there are these complex/powerfull boats on etherium
that examine the call stack of 'interesting' contracts.
Then decide to 'front run' them, to see if they get
unclaimed money due to the mistake.
g) This is what happened in the situation described in this audio clip.
The user who made a mistake (represented by this researcher/engineering team) - tried to reclaim the lost money by executing another transaction (as the original transaction was committed, so no way to reverse it).
But a bot noticed what they are doing, paid more 'gas' and executed that in front of them -- and got the money.
So the rescue operation was not successful.
But existence of these powerful bots witnessed.
---
There was also an interesting philosophical discussion, where an environment were the smartest, the most inventive and the most resourceful win -- can lead to life depleting competition that never ends until the most powerful wins.
And what type of governing system could prevent that, without unfairness, selectivity and corruption that typically comes (at later stages) -- with the 'oversight'.
My short summary:
a) In Ethereum, smart contracts must execute calls to other contracts within a 'single transaction'. A transaction can be rolled back or committed.
b) if an engineer of contract missed a step a call, but a transaction is committed, there is no way to reverse/cancel it.
c) In this specific case a person executed steps in a transaction, but missed one of the steps. That step was to 'retrieve' the money due to him/her from another exchange contract, after sending to it some valuable tokens.
d) so the money were not retrieved (I think worth 12K USD).
e) On Ethereum, it is possible to execute steps, ahead of another user, if you offered to pay more 'gas'. Meaning that somebody could call the 'retrieve money' from a contract, if they paid more 'gas' for that call, and if you failed to execute 'retrieve money' from within a transaction you started earlier.
f) there are these complex/powerfull boats on etherium that examine the call stack of 'interesting' contracts. Then decide to 'front run' them, to see if they get unclaimed money due to the mistake.
g) This is what happened in the situation described in this audio clip.
The user who made a mistake (represented by this researcher/engineering team) - tried to reclaim the lost money by executing another transaction (as the original transaction was committed, so no way to reverse it).
But a bot noticed what they are doing, paid more 'gas' and executed that in front of them -- and got the money. So the rescue operation was not successful. But existence of these powerful bots witnessed.
---
There was also an interesting philosophical discussion, where an environment were the smartest, the most inventive and the most resourceful win -- can lead to life depleting competition that never ends until the most powerful wins.
And what type of governing system could prevent that, without unfairness, selectivity and corruption that typically comes (at later stages) -- with the 'oversight'.