Sharding + CasperとなったEthereum2.0を中心に, Hybrid Casper FFGの解説とその後でてきたBeacon Chainの現状の解説を試みました. すぐ古くなってしまうのと, 正しく理解できてないところもあると思うので, 参考までに.

1. BLOCKCHAIN
Ethereum
2018 / 08 / 28
@zigen
- Casper Sharding -

2. zigen
P R O F I L E
•
•
L I K E
BLOCKPARTY
•
•

3. E t h e r e u m
•
•
BLOCKPARTY
S h a r d i n g + C a s p e r = E t h 2 . 0
•
•

4. C a s p e r t h e F r i e n d l y F i n a l i t y G a d g e t
• Proof of Stake-based Finality
• Hybrid Casper / PoS on PoW / Vitalik's Casper
• New Fork Choice Rule
• EIP-1011(deprecated)
BLOCKPARTY
C a s p e r
C a s p e r t h e F r i e n d l y G h o s t
• A Correct By Construction
• Full Casper / Vlad's Casper
•

5. CasperFFG
https://www.slideshare.net/teramotokentaro/inside-casper

6. • Casper Contract
• Validator
• Client/Miner
BLOCKPARTY
C a s p e r F F G
github.com/ethereum/casper
github.com/karlfloersch/pyethereum
gitHub.com/paritytech/parity-ethereum

7. 1. Casper Contract
2. Validator Casper Contract , 1500Eth
3. 1 (50Block) Validator Vote
4. Casper Contract Vote , slash/reward
5. Miner Casper Contract Fork
6. Validator logout Casper Contract
7. ( ) , Validator logout ,
BLOCKPARTY
C a s p e r F F G

8. BLOCKPARTY
C a s p e r F F G
Block1 Block2 Block3Block0 Block49 Block50
Epoch 0 Epoch 1
Checkpoint: validator vote
• Epoch 50Block
• validator Epoch vote

9. BLOCKPARTY
C a s p e r F F G
Block1 Block2 Block3Block0 Block49 Block50
Epoch 0
• Fork , Validator checkpoint
Block3' Block49' Block50
Validators
Vote

10. BLOCKPARTY
C a s p e r F F G
Block1 Block2 Block3Block0 Block49 Block50
Epoch 0
• 2/3 vote Justified
Block3' Block49' Block50
Validators
Vote
Justified

11. BLOCKPARTY
C a s p e r F F G
Block0 Block49 Block50
Epoch 0
• Epoch vote
• 2/3 vote
Block49' Block50'
Validators
Vote
Justified
Block99
Block99'
Epoch 1

12. BLOCKPARTY
C a s p e r F F G
Block0 Block49 Block50
Epoch 0
• Justified Checkpoint Justified
• , Justified Checkpoint , Finalize
Block49' Block50'
Validators
Finalized
Block99
Block99'
Epoch 1
Justified

13. BLOCKPARTY
C a s p e r F F G
Block0 Block49 Block50
Epoch 0
, Checkpoint Justified
Block49' Finalized
Block49' Block50'
Validators
Justified
Block99
Block99'
Epoch 1
Justified

14. BLOCKPARTY
C a s p e r F F G
Block0 Block49 Block50
Epoch 0
vote validator
Block49' Block50'
Validators
Justified
Block99
Block99'
Epoch 1
Justified

15. Validator Registration

16. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
Valcode
Purity checker

17. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
Valcode
Purity checker
Ether (Stake)
checkpoint vote

18. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
Valcode
Purity checker
Validator msg
signature

19. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
Valcode
Purity checker
Validator ,
vote ,

20. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
Valcode
Purity checker
Validator deploy Valcode contract

21. BLOCKPARTY
C a s p e r F F G - v a l i d a t o r r e g i s t r a t i o n -
Casper Contract
Validator
2. Deposit(valcode_addr)
Valcode
1. Deploy validation contract
3. Register Validator
8. Log validator index
4. raw_call(valcode_addr)
Purity checker
5. Fetch bytecode6. Purity check
7. Return result

22. Vote

23. BLOCKPARTY
C a s p e r F F G - v o t e -
Casper Contract
Validator
Valcode
Message Hasher
Vote msg hash
Contract

24. BLOCKPARTY
C a s p e r F F G - v o t e -
Casper Contract
Validator
1. Vote(msg)
Valcode
8. Process reward/slash
2. raw_call(msg)
Message Hasher
5. raw_call(msg, sig, hash)
3. Hash
4. Msg Hash
6. Verify msg
7. Result

25. BLOCKPARTY
V o t e M e s s a g e
Block0 Block49 Block50
Epoch 0
Block49' Block50'
Vote
Block99
Block99'
Epoch 1
• Validator Index
• Target Hash
• Target Epoch
• Source Epoch
• Signature
N
Hash(Block99')
1
0
Sig(Msg)
Source Target

26. Casper ❤ Sharding
Deprecating EIP 1011 in favor of a Casper+Sharding design
https://medium.com/@djrtwo/casper-%EF%B8%8F-sharding-28a90077f121

27. Casper FFG ,

30. BLOCKPARTY
S h a r d i n g + C a s p e r
• Sharding CasperFFG
https://twitter.com/VitalikButerin/status/1029905990085357568

31. Casper+Sharding v2.1
- Work in progress @ 2018, 8/28 -
https://notes.ethereum.org/SCIg8AH5SA-O4C1G1LYZHQ?view

32. S h a s p e r
BLOCKPARTY
01
02
03
Shard ,
Decentralized
Security
shard validator , ,
Scalabilty

33. C a s p e r + S h a r i n g
BLOCKPARTY
01
02
03
Main PoS Chain / Sharding Manager Contract (Validator Shuffling)
Main PoW Chain Peg
Full PoS Casper FFG / IMD GHOST
Recursive Proximity to Justification: "RPJ"
ShardChain
Account State Transaction PoS
1024
Beacon Chain

34. Beacon Chain

35. BLOCKPARTY
B e a c o n C h a i n
• Full Proof of Stake Casper FFG
• Main PoW Chain Peg
• Validator
Block Main PoW Chain
BeaconBlock 1 2 3 Beacon Chain63
1slot(8sec)
1cycle(64slot)

36. BLOCKPARTY
B e a c o n C h a i n B l o c k • Slot Number
• Active State Root
• Crystallized State Root
• PoW Chain Ref
• Parent Hash
• Randao Reveal
Block Main PoW Chain
BeaconBlock 1 2 3 Beacon Chain63
1slot(8sec)
1cycle(64slot)

37. Active State
Crystallized State
• Slot Number
• Active State Root
• Crystallized State Root
• Randao Reveal
• PoW Chain Ref
• Parent Hash
BLOCKPARTY
B e a c o n C h a i n B l o c k
• Pending Attestations
• Recent Block Hashes
128 Block Hash
Parent Beacon Chain BlockPoW Block
• Validators
• Last State Recalc
Crystallized State slot
• Indices For Slots
Validator Slot , Shard
• Last Justified Slot
• Justified Streak
Justifed
• Last Finalized Slot
• Crosslinking Start Shard
• CrosslinkRecords
1Cycle
1Block

38. BLOCKPARTY
B e a c o n C h a i n
Block Main Chain (PoW)
BeaconBlock Beacon Chain (PoS)
Shard Chain (PoS)Block

39. IMD GHOST
https://ethresear.ch/t/immediate-message-driven-ghost-as-ffg-fork-choice-rule/2561

40. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
• IMD GHOST Fork Choice Rule
• Hybrid Casper FFG
•
• RPJ
1
2 3 4
2' 3' 4'

41. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
• Validator vote
Validators

42. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
• Validator vote
• , vote
15 16 65
55 56
Validators
Canonical

43. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
Fork Tree ,
vote Canonical
15 16 65
55 56
Validators
Canonical

44. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
Fork Tree ,
vote Canonical
15 51
65 20
Validators
Canonical

45. BLOCKPARTY
I m m e d i a t e - M e s s a g e - D r i v e n G H O S T
Hybrid CasperFFG , Finalized/Justified .
, .
15 51
65 20
Validators
Canonical

46. Role

47. BLOCKPARTY
R o l e
Validator: VRC 32ETH
Proposer: Validator
Attester: / Validator
Validators

48. BLOCKPARTY
V a l i d a t o r R e g i s t r a t i o n C o n t r a c t : " V R C "
Main PoW Chain VRC
32ETH
Beacon Chain watch
Validator
Main PoW Chain
Beacon Chain
VRC
Event
Deposit pubkey, 32ETH

49. Beacon Chain
BLOCKPARTY
B e a c o n C h a i n S t a t e
Beacon Chain Validator Shard
Crystallized State ,
Validator Slot Shard
Validator
Main PoW Chain
VRC
Shard Chain 1
Shard Chain 2
Shard Chain 3
Shard Chain N

50. Beacon Chain
BLOCKPARTY
B e a c o n C h a i n S t a t e
Shard Validator , Shard CrossLink
CrossLink dynasty shard_block_hash
CrossLink CrystallizedState
Validator
Main PoW Chain
VRC
Shard Chain 1
Shard Chain 2
Shard Chain 3
Shard Chain N
CrossLink

51. Beacon Chain
BLOCKPARTY
B e a c o n C h a i n S t a t e
Attester CrossLink Shard ,
AttestationRecord
ActiveState beacon chain
Attester Proposer
Validator
Main PoW Chain
VRC
Shard Chain 1
Shard Chain 2
Shard Chain 3
Shard Chain N
CrossLink
https://notes.ethereum.org/SCIg8AH5SA-O4C1G1LYZHQ?view#Per-block-processing

52. BLOCKPARTY
s p e c
• Validator Login/Logout
• Shard Chain ,
• Shard Chain
• Canonical Chain vote Slash
• Slashing Condition
• Shard
• Validator Shard
•

53. BLOCKPARTY
• VRC ETH Shard
• Attester Proposer
•

54. Implementation

55. BLOCKPARTY
E t h e r e u m 2 . 0
• Prysm
• Nimbus
• Diamond Drops
• Lighthouse
• Loadstar
• Harmony
github.com/prysmaticlabs/prysm
github.com/status-im/nimbus
github.com/Drops-of-Diamond/diamond_drops
github.com/sigp/lighthouse
github.com/ChainSafeSystems/lodestar_chain
github.com/ethereum/ethereumj
Go
Nim
Rust
Rust
JS
Java

56. P r y s m b y P r y s m a t i c L a b s
•
• Discord
• Geth ,
• github.com/prysmaticlabs/prysm

57. https://docs.google.com/drawings/d/1ZzzV7BNTZUl5jXkyPAXpyeW1pt7Dtz_m6KD9usQQ0o4/edit?usp=sharing
Prysm

58. • Ethereum sharding general introduction (deprecated) -- March 19th
• Ethereum2.0 -- July 6th
• what you can do for ethereum2.0 a.k.a. sharding -- June 12th
• Sharding FAQ
• github.com/ethereum/sharding (deprecated)
• Epoch-less CasperFFG Liveness/Safety argument
• Simple synchronous cross shard transaction protocol
• Discussion p2p message serialization standard
• CBC Casper in the face of the new PoS Sharding plasns on Ethereum
• Prysmatic Labs Biweekly Development updates
• Immediate-Message-Driven-GHOST as FFG Fork choice rule
• Beacon Chain Casper FFG RPJ mini spec
https://notes.ethereum.org/9MMuzWeFTTSg-3Tz_YeiBA?view#
hwwhww
ethresearch , gitter ethereum/sharding