ec clarifications and updates #334

bvohaska · 2019-06-11T18:10:58Z

Updates to definitions, ticket generation, and electionProof generation

…bvohaska/ec

…ately

sternhenri · 2019-07-10T18:05:02Z

@pooja review plz :D

sternhenri

touched up for recent changes

dignifiedquire · 2019-07-11T13:29:57Z

data-structures.md

+A ticket is a shared random value stapled to a particular block in the chain. Every miner must produce a new ticket each time they run a leader election attempt. In that sense, every new block produced will have one or more associated tickets (in the case the block took multiple leader election attempts to produce).
+
+```go
+type Ticket struct {


please update this to the new IPLD schema syntax

Holding off on specifying methods and the like for now, if that is what is meant...

dignifiedquire · 2019-07-11T13:30:26Z

data-structures.md

+
+```go
+type ElectionProof struct {
+  TODO HS


maybe make it a bit more clear that this is not an actual field 😆

dignifiedquire · 2019-07-11T13:30:54Z

definitions.md


 #### GHOST

+GHOST is an acronym for `Greedy Heaviest Observable SubTree`, a class of blockchain structures in which multiple blocks can validly be included in the chain at any given height or round. GHOSTy protocols produce blockDAGs rather than blockchains and use a weighting function for fork selection, rather than simply picking the longest chain.


maybe a link to a reference?

dignifiedquire · 2019-07-11T13:31:20Z

definitions.md

+
+#### Height
+
+`Height` refers to the number of `TipSets` that have passed between this `TipSet` and the genesis block (which starts at block height 0). If a `TipSet` contains multiple blocks, each block in the TipSet will have the same `height`.


please say how this interacts with null blocks here

FWIW the go-filecoin code, and everyones intuitions, say that "height" is the number of rounds, not the number of tipsets. We'll be swimming upstream to redefine that here. At present, the code doesn't have a use for a count of the non-null tips.

to be handled in a different PR per #351

dignifiedquire · 2019-07-11T13:31:50Z

definitions.md

 #### Round

-A round refers to the period over which a new leader election occurs and a block is generated if a leader is found. Typically this means a new block will be mined at every round, though some rounds may see 0 or multiple blocks generated.
+A round refers to the period over which a new leader election occurs and a block is generated if a leader is found. Typically this means a new block will be mined at every round, though 


missing . at the end

dignifiedquire · 2019-07-11T13:32:39Z

definitions.md

- to elect a leader in Expected Consensus.
-
-See more on [Expected Consensus](expected-consensus.md) and [PoSTs](proofs.md).
+A `ticket` is used as a source of randomness in EC leader election. Every block depends on an `ElectionProof` derived from a `ticket`. At least one new `ticket` is produced with every new block. Ticket creation will be described [here](./expected-consensus.md#Ticket-generation).


maybe "is described here"?

dignifiedquire · 2019-07-11T13:35:50Z

definitions.md

 #### TipSet

-A collection of blocks mined by different miners, each an elected leader of a given epoch. All tip sets have the same parent-set and epoch number (height). TODO add picture.
+ A `TipSet` is a set of blocks that have the same parent set and same number of `tickets`, which implies they will have been mined at the same `height`. A `TipSet` can contain multiple blocks if more than one miner successfully mines a block at the same `height` as another miner. `TipSets` contain 1 or more blocks (i.e. null blocks are not included in `TipSets`).


This is a bit circular Above it says that height is the number of tipsets passed since genesis, and here it is tipset are the blocks with the same height.

i.e. null blocks are not included in TipSets

then where are they included? aren't they part of the block technically?

Disagree with circularity. The circular bit is just a reframing that helps cement what height is here. Re null blocks, removed. Confusing bit. A Tipset can never include just a null block, they are indeed included as part of the block, technically (through the ticket array).

Null blocks is a confusing concept overall we should get rid of.

dignifiedquire · 2019-07-11T13:36:46Z

definitions.md


+#### VDF
+
+A verifiable function that guarantees a time delay given some hardware assumptions and a small set of requirements. These requirements are efficient proof verification, random output, and strong sequentiality. Verifiable delay functions are formally defined [here](https://eprint.iacr.org/2018/601). A VDF will receive {set of public parameters (similar to [these](https://eprint.iacr.org/2018/712.pdf)), seed} and output {proof of correctness, output value}.


maybe add the title of these publications?

also the use of curly braces is very confusing

dignifiedquire · 2019-07-11T13:37:30Z

expected-consensus.md

@@ -1,70 +1,42 @@
-# Expected Consensus
+#  Expected Consensus


too much space ;)

sternhenri · 2019-07-12T05:34:59Z

Thank you!

…

On Thu, Jul 11 2019 at 22:33, Henri Stern < ***@***.*** > wrote: Noted. Will amend in a different PR to disambiguate rounds and heights! On Thu, Jul 11 2019 at 21:31, < ***@***.*** > wrote: > > > ***@***.**** commented on this pull request. > > > > In definitions.md ( > #334 (comment) ) > : > > > @@ -101,6 +105,12 @@ The Generation Attack Threshold is equal to the > Polling Time + some Grace Period #### GHOST +GHOST is an acronym for > `Greedy Heaviest Observable SubTree`, a class of blockchain structures in > which multiple blocks can validly be included in the chain at any given > height or round. GHOSTy protocols produce blockDAGs rather than > blockchains and use a weighting function for fork selection, rather than > simply picking the longest chain. + +#### Height + +`Height` refers to the > number of `TipSets` that have passed between this `TipSet` and the genesis > block (which starts at block height 0). If a `TipSet` contains multiple > blocks, each block in the TipSet will have the same `height`. > > FWIW the go-filecoin code, and everyones intuitions, say that "height" is > the number of rounds, not the number of tipsets. We'll be swimming > upstream to redefine that here. At present, the code doesn't have a use > for a count of the non-null tips. > > > > — > You are receiving this because your review was requested. > Reply to this email directly, view it on GitHub ( > #334?email_source=notifications&email_token=AAZUC2YHNZIR7KU3M74T2P3P7ACKRA5CNFSM4HXB7TT2YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOB6HV75Q#discussion_r302823547 > ) , or mute the thread ( > https://github.com/notifications/unsubscribe-auth/AAZUC24F3JBZSP2NYEJB6NLP7ACKRANCNFSM4HXB7TTQ > ). > > >

…ska/ec

bvohaska and others added 2 commits June 11, 2019 13:23

Restructured definitions. Added rough diagram example.

7604111

Changed ticket gen and election proof algorithm

68b61f8

bvohaska requested review from sternhenri and whyrusleeping June 11, 2019 18:10

bvohaska mentioned this pull request Jun 11, 2019

Clarify use of signatures in EC #290

Closed

sternhenri added 3 commits July 8, 2019 10:10

Merge branch 'bvohaska/ec' of github.com:filecoin-project/specs into …

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…bvohaska/ec

going through changes

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merge with master, move definitions and data structures work appropri…

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…ately

sternhenri requested a review from pooja July 10, 2019 18:05

sternhenri approved these changes Jul 10, 2019

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dignifiedquire reviewed Jul 11, 2019

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dignifiedquire changed the title ~~bvohaska/ec~~ ec clarifications and updates Jul 11, 2019

dig eagle eye protection

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sternhenri added 2 commits July 12, 2019 15:47

Merge branch 'master' of github.com:filecoin-project/specs into bvoha…

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…ska/ec

touch up per comments

cf2cb74

sternhenri mentioned this pull request Jul 13, 2019

Spec precise VRF use in EC #390

Merged

dignifiedquire merged commit 2b7f902 into master Jul 16, 2019

dignifiedquire deleted the bvohaska/ec branch July 16, 2019 17:26


		#### GHOST

		GHOST is an acronym for `Greedy Heaviest Observable SubTree`, a class of blockchain structures in which multiple blocks can validly be included in the chain at any given height or round. GHOSTy protocols produce blockDAGs rather than blockchains and use a weighting function for fork selection, rather than simply picking the longest chain.


		#### Height

		`Height` refers to the number of `TipSets` that have passed between this `TipSet` and the genesis block (which starts at block height 0). If a `TipSet` contains multiple blocks, each block in the TipSet will have the same `height`.


		#### VDF

		A verifiable function that guarantees a time delay given some hardware assumptions and a small set of requirements. These requirements are efficient proof verification, random output, and strong sequentiality. Verifiable delay functions are formally defined [here](https://eprint.iacr.org/2018/601). A VDF will receive {set of public parameters (similar to [these](https://eprint.iacr.org/2018/712.pdf)), seed} and output {proof of correctness, output value}.

ec clarifications and updates #334

ec clarifications and updates #334

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bvohaska commented Jun 11, 2019

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sternhenri commented Jul 12, 2019 via email

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