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It took me a while to actually understand how proof-of-work mining works because seemingly every article one the subject gives too abstract of an explanation. T

It took me a while to actually understand how proof-of-work mining works because seemingly every article one the subject gives too abstract of an explanation. Turns out it's not that complex if you understand what a cryptographic hash is. Just take a block (a list of recent transactions) and take a SHA-256 hash if it over and over with slight variations until you get a hash that starts with enough consecutive zeroes. I'm having the same issue with understanding proof-of-space. Could someone give a technical explanation for those of us that understand basic cryptography (but aren't professional cryptographists)?

wmf 5y ago
There are multiple flavors of proof of space and they seem to be based on quite complex math to the extent that a simple explanation may not be possible.
- maks25 5y ago
  I don’t think I have ever heard of proof of space, is it the same as proof of stake?
  - warkdarrior 5y ago
    Completely different things. In Proof of Stake, the network (roughly!) allocates rewards for validating transactions based on the amount of coins you have, i.e., your stake in the network. In Proof of Space, the network allocates rewards based on you proving that you are really storing the data you were supposed to store. If you fail to produce a proof for some data item the network expected you to have stored, you lose the reward. More info: https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_stake https://en.wikipedia.org/wiki/Proof_of_stake
    - Dylan16807 5y ago
      > In Proof of Space, the network allocates rewards based on you proving that you are really storing the data you were supposed to store. Sort of? But you're usually not really storing data for proof of space. That's a different kind of system.
      - conradev 5y ago
        Yeah, that is called proof of storage in Filecoin: https://spec.filecoin.io/#section-algorithms.pos https://spec.filecoin.io/#section-algorithms.pos
    - gojomo 5y ago
      Another important wrinkle is that Chia’s proof-of-space needs you to prove you’ve stored the right cryptographic noise - rather than, for example, any useful data.
      - foobar33333 5y ago
        Another proof of waste shitcoin. Just what the world needed.
  - CharlesW 5y ago
    They are different. Chia isn't Proof of Stake because how many XCH has no impact on your odds of winning more. https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_stake https://en.wikipedia.org/wiki/Proof_of_stake
    - CharlesW 5y ago
      Sorry, dropped a couple words: "how many XCH you have has no impact"
  - gojomo 5y ago
    No - it’s a bit more like preprinting big ranges of lottery tickets, that require giant look-up tables moreso than raw computation. So it requires the dedication of some hard/rivalrous real resource, storage space, other than either strictly energy/CPU (PoW) or the protocol’s own tokens (PoStake). See the Chia ‘Green Paper’ for more details.
  - deleted 5y ago
    [deleted]
- 0x264 5y ago
  There always is a simple explanation: Resulting from (1) removing irrelevant details (details crucial for an implementation, but irrelevant for an initial mental model) and (2) making use of analogies built around already known concepts. "Complex maths" is never an excuse to not find that explanation. Disclaimer: I am a pure mathematician.
chade 5y ago
Proof-of-space is essentially stored Proof-of-work. You are pre-filling your drive with many cryptographic hash's. When a challenge comes in the software will do a quick check to see if any of your plots could possibly have a proof (a hash with sufficient zeros for that challenge). If any of your plots pass this filter then the plot is looked up on the HDD to check if it does indeed contain a proof. The difficulty, the number of zeros needed for a hash to be considered a proof, adjusts as the network grows to ensure a steady supply of coins. With proof-of-work you are printing lottery tickets every time a challenge comes in, then throwing them away and starting again, with Proof-of-space you are printing your tickets once and then storing them for years. There is extra layers, Chia is actually proof-of-space-and-time, so that you can't win by faking proof-of-space with proof-of-work.
- ronyfadel 5y ago
  For someone uninitiated: what if you had high computing power? Instead of scanning your HDD, can’t you generate these hashes on the spot?
  - insulanus 5y ago
    Yes, you can. That's called a grinding attack. There is mitigation in the proof-of-space construction for exactly that. That is also the reason that they will have to move to more expensive proofs as time goes on, and hardware improves.
- vladvasiliu 5y ago
  > with Proof-of-space you are printing your tickets once and then storing them for years. So then where's the issue with SSD wear, and wouldn't it be more interesting for people to have spinning drives (for the better ratio of GB / $)? > There is extra layers, Chia is actually proof-of-space-and-time, so that you can't win by faking proof-of-space with proof-of-work. Is it because of this? So you'd have to print your lottery tickets often enough that a faster drive may help you?
  - deleted 5y ago
    [deleted]
tylersmith 5y ago
One way is using zero knowledge computational integrity proofs. They allow me to prove to you that I know of pre-image of some hash without revealing what it is. Say the network has seen 1TB of data before with hash H. It can generate a random number as a challenge, and request a miner to prove they have access to the 1TB worth of pre-image at the same time it has access to the random challenge. The only way for a miner to compute such a proof is to have the 1TB of data stored somewhere.
tromp 5y ago
What you describe is an instance of the Hashcash Proof-of-Work. There are many other types of PoW, which don't amount to just computing a hash function [1]. [1] https://cryptorials.io/beyond-hashcash-proof-work-theres-mining-hashing https://cryptorials.io/beyond-hashcash-proof-work-theres-min...

wmf 5y ago

There are multiple flavors of proof of space and they seem to be based on quite complex math to the extent that a simple explanation may not be possible.

maks25 5y ago
I don’t think I have ever heard of proof of space, is it the same as proof of stake?
- warkdarrior 5y ago
  Completely different things. In Proof of Stake, the network (roughly!) allocates rewards for validating transactions based on the amount of coins you have, i.e., your stake in the network. In Proof of Space, the network allocates rewards based on you proving that you are really storing the data you were supposed to store. If you fail to produce a proof for some data item the network expected you to have stored, you lose the reward. More info: https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_stake https://en.wikipedia.org/wiki/Proof_of_stake
  - Dylan16807 5y ago
    > In Proof of Space, the network allocates rewards based on you proving that you are really storing the data you were supposed to store. Sort of? But you're usually not really storing data for proof of space. That's a different kind of system.
    - conradev 5y ago
      Yeah, that is called proof of storage in Filecoin: https://spec.filecoin.io/#section-algorithms.pos https://spec.filecoin.io/#section-algorithms.pos
  - gojomo 5y ago
    Another important wrinkle is that Chia’s proof-of-space needs you to prove you’ve stored the right cryptographic noise - rather than, for example, any useful data.
    - foobar33333 5y ago
      Another proof of waste shitcoin. Just what the world needed.
- CharlesW 5y ago
  They are different. Chia isn't Proof of Stake because how many XCH has no impact on your odds of winning more. https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_space https://en.wikipedia.org/wiki/Proof_of_stake https://en.wikipedia.org/wiki/Proof_of_stake
  - CharlesW 5y ago
    Sorry, dropped a couple words: "how many XCH you have has no impact"
- gojomo 5y ago
  No - it’s a bit more like preprinting big ranges of lottery tickets, that require giant look-up tables moreso than raw computation. So it requires the dedication of some hard/rivalrous real resource, storage space, other than either strictly energy/CPU (PoW) or the protocol’s own tokens (PoStake). See the Chia ‘Green Paper’ for more details.
- deleted 5y ago
  [deleted]
0x264 5y ago
There always is a simple explanation: Resulting from (1) removing irrelevant details (details crucial for an implementation, but irrelevant for an initial mental model) and (2) making use of analogies built around already known concepts. "Complex maths" is never an excuse to not find that explanation. Disclaimer: I am a pure mathematician.

chade 5y ago

Proof-of-space is essentially stored Proof-of-work. You are pre-filling your drive with many cryptographic hash's. When a challenge comes in the software will do a quick check to see if any of your plots could possibly have a proof (a hash with sufficient zeros for that challenge). If any of your plots pass this filter then the plot is looked up on the HDD to check if it does indeed contain a proof. The difficulty, the number of zeros needed for a hash to be considered a proof, adjusts as the network grows to ensure a steady supply of coins. With proof-of-work you are printing lottery tickets every time a challenge comes in, then throwing them away and starting again, with Proof-of-space you are printing your tickets once and then storing them for years. There is extra layers, Chia is actually proof-of-space-and-time, so that you can't win by faking proof-of-space with proof-of-work.

ronyfadel 5y ago
For someone uninitiated: what if you had high computing power? Instead of scanning your HDD, can’t you generate these hashes on the spot?
- insulanus 5y ago
  Yes, you can. That's called a grinding attack. There is mitigation in the proof-of-space construction for exactly that. That is also the reason that they will have to move to more expensive proofs as time goes on, and hardware improves.
vladvasiliu 5y ago
> with Proof-of-space you are printing your tickets once and then storing them for years. So then where's the issue with SSD wear, and wouldn't it be more interesting for people to have spinning drives (for the better ratio of GB / $)? > There is extra layers, Chia is actually proof-of-space-and-time, so that you can't win by faking proof-of-space with proof-of-work. Is it because of this? So you'd have to print your lottery tickets often enough that a faster drive may help you?
- deleted 5y ago
  [deleted]

tylersmith 5y ago

One way is using zero knowledge computational integrity proofs. They allow me to prove to you that I know of pre-image of some hash without revealing what it is. Say the network has seen 1TB of data before with hash H. It can generate a random number as a challenge, and request a miner to prove they have access to the 1TB worth of pre-image at the same time it has access to the random challenge. The only way for a miner to compute such a proof is to have the 1TB of data stored somewhere.

tromp 5y ago

What you describe is an instance of the Hashcash Proof-of-Work. There are many other types of PoW, which don't amount to just computing a hash function [1]. [1] https://cryptorials.io/beyond-hashcash-proof-work-theres-mining-hashing https://cryptorials.io/beyond-hashcash-proof-work-theres-min...