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GHOST can provide higher transaction throughput by minimized block interval, but community people seldom mention it. What's wrong with GHOST?
Why not implement GHOST in bitcoin?
Answers
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GHOST is outdated, the more relevant protocol based on recent research by Aviv Zohar et al is called "SPECTRE" - https://medium.com/@avivzohar/the-spectre-protocol-7dbbebb707b5, https://eprint.iacr.org/2016/1159.pdf.
It has many advantages over the traditional longest-chain rule of Bitcoin, but:
It requires a hard fork, something which has never been done intentionally in Bitcoin.
It is a huge departure from Bitcoin's protocol, and as such it will require extensive research and testing before it is even considered for inclusion in Bitcoin.
There are alts under development that are trying to implement SPECTRE, if it works well for them it can be a first step towards consideration in Bitcoin. You don't risk untested ideas on a $100B production system.
Thank you! This 2 points are so called "bitcoin conservative" right? – Anderson – 2017-11-14T02:31:23.587
What alts are trying to implement SPECTRE? – Anderson – 2017-11-14T02:31:43.310
@Meni, are there any trade-offs? – renlord – 2017-11-14T02:58:52.257
2@AndersonC: You could say that, they are both related to the rigor required to make changes in Bitcoin. I'm not sure about the specific alts, but I'm sure we'll all know when they're ready. – Meni Rosenfeld – 2017-11-14T10:00:31.260
@renlord - SPECTRE is more computationally intensive than longest chain. Furthermore, the main advantage of SPECTRE is that it allows shorter time between blocks without losing hashpower, but this has other tradeoffs, notably more resource requirements from SPV clients. Other than that, AFAIR SPECTRE is strictly superior, though I may be missing something. – Meni Rosenfeld – 2017-11-14T10:02:58.040
FYI PHANTOM is the latest reincarnation of GHOST/SPECTRE. – ripper234 – 2018-01-31T18:23:39.190
BIP 50 was a hard fork. – MCCCS – 2018-05-15T16:17:21.063
@MCCCS: That was an emergency patch rather than a planned protocol upgrade, I don't think it counts. Anyway, I'll try to work on the phrasing. – Meni Rosenfeld – 2018-05-15T17:02:11.803
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One thing to note also is that even ethereum is not using GHOST and I dont see any coin using some sort of ghost or phantom protocol at this point, so yeah its hard to expect bitcoin will jump to it before it is tested elsewhere.
https://ethereum.stackexchange.com/questions/38121/why-did-ethereum-abandon-the-ghost-protocol
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We are using a modified version of Ghost at Hycon. The original plan was to move forward with Spectre, but as yet there are some unsolved issues, particularly around selfish mining and efficient resolution of superposition states at the tips of the DAG. Ghost is useful when the block time is shorter and orphan events are more common. In the case of bitcoin, these days orphan events are rare, so unless it was decided to reduce the block time it is unnecessary.
1ghost also massively amplifies selfish mining... my understanding is that this is why ethereum dropped it. Impressive that there are other altcoins more recklessly yolo than ethereum... – G. Maxwell – 2019-02-12T02:36:48.947
Our implementation includes the difficulty from uncle blocks as part of our dynamic difficulty adjustment, negating selfish mining strategies as laid out here. To quote the article "(a difficulty algorithm) based on the chain weight (weight/time), then mining uncles would not increase the rate of the best chain, and uncle mining would be prevented."
1Side note if the bitcoin community wouldn't even allow for 8MB blocks or segwit2x I doubt they would even think about GHOST. – Marc Alexander – 2017-11-13T16:53:25.430