4 ms·

This sounds like a fallacy of the inverse. Those contracts not being hacked yet is no proof that they are resistant to hacks.

theli0nheart 5y ago
It's not clear what fallacy you're thinking about because the fallacy of the inverse is not it. From https://en.wikipedia.org/wiki/Confusion_of_the_inverse https://en.wikipedia.org/wiki/Confusion_of_the_inverse: > Confusion of the inverse, also called the conditional probability fallacy or the inverse fallacy, is a logical fallacy whereupon a conditional probability is equated with its inverse; that is, given two events A and B, the probability of A happening given that B has happened is assumed to be about the same as the probability of B given A, when there is actually no evidence for this assumption.[1][2] More formally, P(A|B) is assumed to be approximately equal to P(B|A).
- Closi 5y ago
  The inverse of "any contract that has been hacked was insecure" is "any contract that hasn't been hacked must be secure". I think this is what OP meant. If something has been around for a long time it does probably mean it's less likely there is a really obvious security flaw, but it doesn't necessarily mean it is 'rock-solid' as plenty of things that have been seen to be 'rock-solid' in the past have turned out to be insecure.
  - solomonb 5y ago
    yes this is what I was implying. I am curious how else the previous commenter would interpret my statement.
    - theli0nheart 5y ago
      Let's formalize this to make it easier to discuss. 𝐏(𝐀) = 𝐏(contract has been hacked) 𝐏(¬𝐀) = 𝐏(contract has not been hacked) 𝐏(𝐁) = 𝐏(contract is hack resistant) Relevant conditional probabilities: 𝐏(𝐁|¬𝐀) = 𝐏(contract is hack-resistant given that it has not been hacked) 𝐏(¬𝐀|𝐁) = 𝐏(contract has not been hacked given that it is hack-resistant) The fallacy of the inverse would be assuming that: > The probability that a contract is hack-resistant, given that it has not been hacked, is approximately equal to the probability that it has not been hacked, given that it's hack resistant. More succinctly: 𝐏(𝐁|¬𝐀) ≅ 𝐏(¬𝐀|𝐁) In https://news.ycombinator.com/item?id=27666484 https://news.ycombinator.com/item?id=27666484, the fallacy of the inverse was presented as "those contracts not being hacked yet is no proof that they are resistant to hacks" or "NOT (NOT A implies B)", i.e.: ¬(¬𝐀 → 𝐁) In summary: 𝐏(𝐁|¬𝐀) ≅ 𝐏(¬𝐀|𝐁) => the fallacy of the inverse and ¬(¬𝐀 → 𝐁) => statement in comment These two statements are fundamentally different. Note that the first statement is a comparison of probabilities, and the second is not. They're not the same. There might be another fallacy at play here, but it's not the fallacy of the inverse.
      - Closi 5y ago
        To be honest, I don’t fully follow the above, and I’m not sure if this formalises the same problem. Copying the definition from Wikipedia: > If P, then Q. > Therefore, if not P, then not Q. In this case, we could plug in the below values: P = Contract Hacked Q = Insecure I.e. if the contract has been hacked the code was insecure. Therefore if the contract has not been hacked, it is not insecure.
cylon13 5y ago
It is pretty good evidence that they are resistant to hacks though, and speaking about interesting evidence that doesn't pass the bar of proof isn't some kind of logical fallacy. That's a pretty high bar to set for what you're willing to integrate information-wise about the world into your model of it.
- solomonb 5y ago
  I get where you are coming from but this is a highly adversarial environment where huge amounts of other people's money is at stake with a history of very clever hacks. This looks like precisely the sorts of systems where you ought to raise the bar as high as possible. Certain systems may have proven themselves somewhat over time but for this I say there is always the possibility for some extremely sophisticated attack and for any other new system they by definition wont have even this proven track record.

theli0nheart 5y ago

It's not clear what fallacy you're thinking about because the fallacy of the inverse is not it. From https://en.wikipedia.org/wiki/Confusion_of_the_inverse https://en.wikipedia.org/wiki/Confusion_of_the_inverse: > Confusion of the inverse, also called the conditional probability fallacy or the inverse fallacy, is a logical fallacy whereupon a conditional probability is equated with its inverse; that is, given two events A and B, the probability of A happening given that B has happened is assumed to be about the same as the probability of B given A, when there is actually no evidence for this assumption.[1][2] More formally, P(A|B) is assumed to be approximately equal to P(B|A).

Closi 5y ago
The inverse of "any contract that has been hacked was insecure" is "any contract that hasn't been hacked must be secure". I think this is what OP meant. If something has been around for a long time it does probably mean it's less likely there is a really obvious security flaw, but it doesn't necessarily mean it is 'rock-solid' as plenty of things that have been seen to be 'rock-solid' in the past have turned out to be insecure.
- solomonb 5y ago
  yes this is what I was implying. I am curious how else the previous commenter would interpret my statement.
  - theli0nheart 5y ago
    Let's formalize this to make it easier to discuss. 𝐏(𝐀) = 𝐏(contract has been hacked) 𝐏(¬𝐀) = 𝐏(contract has not been hacked) 𝐏(𝐁) = 𝐏(contract is hack resistant) Relevant conditional probabilities: 𝐏(𝐁|¬𝐀) = 𝐏(contract is hack-resistant given that it has not been hacked) 𝐏(¬𝐀|𝐁) = 𝐏(contract has not been hacked given that it is hack-resistant) The fallacy of the inverse would be assuming that: > The probability that a contract is hack-resistant, given that it has not been hacked, is approximately equal to the probability that it has not been hacked, given that it's hack resistant. More succinctly: 𝐏(𝐁|¬𝐀) ≅ 𝐏(¬𝐀|𝐁) In https://news.ycombinator.com/item?id=27666484 https://news.ycombinator.com/item?id=27666484, the fallacy of the inverse was presented as "those contracts not being hacked yet is no proof that they are resistant to hacks" or "NOT (NOT A implies B)", i.e.: ¬(¬𝐀 → 𝐁) In summary: 𝐏(𝐁|¬𝐀) ≅ 𝐏(¬𝐀|𝐁) => the fallacy of the inverse and ¬(¬𝐀 → 𝐁) => statement in comment These two statements are fundamentally different. Note that the first statement is a comparison of probabilities, and the second is not. They're not the same. There might be another fallacy at play here, but it's not the fallacy of the inverse.
    - Closi 5y ago
      To be honest, I don’t fully follow the above, and I’m not sure if this formalises the same problem. Copying the definition from Wikipedia: > If P, then Q. > Therefore, if not P, then not Q. In this case, we could plug in the below values: P = Contract Hacked Q = Insecure I.e. if the contract has been hacked the code was insecure. Therefore if the contract has not been hacked, it is not insecure.

cylon13 5y ago

It is pretty good evidence that they are resistant to hacks though, and speaking about interesting evidence that doesn't pass the bar of proof isn't some kind of logical fallacy. That's a pretty high bar to set for what you're willing to integrate information-wise about the world into your model of it.

solomonb 5y ago
I get where you are coming from but this is a highly adversarial environment where huge amounts of other people's money is at stake with a history of very clever hacks. This looks like precisely the sorts of systems where you ought to raise the bar as high as possible. Certain systems may have proven themselves somewhat over time but for this I say there is always the possibility for some extremely sophisticated attack and for any other new system they by definition wont have even this proven track record.