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Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

eprint.iacr.org

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Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#11

Post by splintercell »

gvhst wrote: post #9
martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

Not sure if you are claiming that BTC currently solves the "more wealth -> more power in system" problem but it clearly doesn't. The current state of affairs is more wealth -> more ASICS R&D and infrastructure budget -> more hash power -> more power in the system.

Matthew principle strikes again.

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#12

Post by martin1975 »

martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

was this submitted to any crypto journals for peer review (CCS, Eurocrypt) or did the author arrive at this conclusion in isolation?

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#13

Post by dgellow »

martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

The Ouroboros paper seems to say that it is 50% resistant. See the parts highlighted here and the additional comments in this forum thread: https://forum.cardano.org/t/is-cardano-51-attack-resistant/1....

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#14

Post by RhodoGSA »

martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

Check out Polkadot - They NPOS system works and not how you described.

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#15

Post by wmf »

poisonborz wrote: post #7

I have the tingling feeling that one could think of a better name for a blockchain protocol.

It's a great name because PoS doesn't require using outside resources (e.g. energy). Once the system gets going it secures itself.

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#16

Post by wmf »

martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

It's true that PoS requires subjectivity to prevent long-range attacks, but everyone is already using subjectivity so this is not an additional constraint. (People say that, in theory, new users might not use subjectivity in PoW but this is not actually true in practice.)

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#17

Post by dane-pgp »

martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

> only be made secure against a maximum of ⅓ byzantine actors

What is the threat model here, and in particular what is the outcome of a successful attack?

For example, if the only "power in the system" the attacker has is the ability to prevent transactions from occurring, then the attacker is damaging the value of their own coins. The honest majority could, as a last resort, also decide to manually fork the currency to invalidate the attacker's coins.

Assuming the ⅓ number is weighted by stake, the attacker is potentially risking billions of dollars in order to carry out this short-term attack. With that amount of money it would be cheaper to locate and destroy the major bitcoin mining farms.

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#18

Post by Geee »

gvhst wrote: post #9
martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

Not sure if you are claiming that BTC currently solves the "more wealth -> more power in system" problem but it clearly doesn't. The current state of affairs is more wealth -> more ASICS R&D and infrastructure budget -> more hash power -> more power in the system.

There's a difference. You can't physically centralize energy production. Local energy price will increase when more energy is used. This ensures that no one can get in a position of control. In PoS, it's possible to get > 50% ownership, and it's game over.

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#19

Post by wmf »

Geee wrote: post #18
gvhst wrote: post #9

Earlier quoted context omitted.

Not sure if you are claiming that BTC currently solves the "more wealth -> more power in system" problem but it clearly doesn't. The current state of affairs is more wealth -> more ASICS R&D and infrastructure budget -> more hash power -> more power in the system.

There's a difference. You can't physically centralize energy production. Local energy price will increase when more energy is used. This ensures that no one can get in a position of control. In PoS, it's possible to get > 50% ownership, and it's game over.

Is 70% of Bitcoin mining still in China?

Re: Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol [pdf] (2019)

#20

Post by dane-pgp »

RhodoGSA wrote: post #14
martindale wrote: post #8

Proof of Stake not only replicates the same dynamics that Bitcoin was designed to eliminate (more wealth -> more power in system) but also can only be made secure against a maximum of ⅓ byzantine actors, compared to Proof of Work's superior ½. As for using it for Layer 1 systems, Andrew Poelstra nailed it in his conclusion [0]: "We showed that by depending only on resources within the system, proof of stake cannot be…

Check out Polkadot - They NPOS system works and not how you described.

I wasn't familiar with Polkadot, but this documentation page seems to be a good introduction to how its "Nominated Proof-of-Stake" system works:

https://wiki.polkadot.network/docs/en/learn-staking

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