Solving the NPoS problem with Phragmen | Substrate Seminar | Archives

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United Kingdom Parity Tech
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Published on ● Video Link: https://www.youtube.com/watch?v=MjOvVhc1oXw


Duration: 1:33:24
962 views
21

Today we're joined by Kian Paimani to discuss Substrate's use of Phragmen's algorithm and it various on- and off-chain implementations.

0:00 Introductions
1:59 Overview - Three varieties of Phragmen
3:04 Sequential Phragmen
10:55 The NPos Problem
15:28 Question: How did we choose the criteria for a "good" NPoS solution
Criticism: The criteria incentivizes validators splitting stake
24:10 Example: Comparing two NPoS solutions
27:23 Question: When is Phragmen run?
30:30 Offline Phragmen
34:55 Offchain Phragmen
41:57 Encoding NPoS Solutions
1:01:37 Validating and Scoring Solutions
1:26:29 Wrap-up

Web3 research article on phragmen: https://research.web3.foundation/en/latest/polkadot/NPoS/index.html
PR where Kian implements this logic he's describing https://github.com/paritytech/substrate/pull/4947
Offline Phragmen Tool: https://github.com/kianenigma/offline-phragmen



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Tags:
Substrate
Phragmen
NPoS
Proof of Stake
Governance
Blockchain