Transcript By: Bryan Bishop
Streamlet: Textbook Streamlined Blockchain Protocols
((…. stream went offline in the other room, had to catch up.))
Show you new consensus protocol called streamlet. We think it is remarkably simple intuitive. This is quite a bold claim, hopefully the protocol will speak for itself
Incredibly subtle, hard to implement in practice. We want to take this reputation and sweep it out the door.
Jump right in. First model the consensus problem. Motivating simplicity as a goal. Spend the bulk of talk, line by line through the protocol By the end, you will be able to understand it and describe it.
Never have I ever been able to understand a consensus protocol in 30 minutes, I hope we will get there.
Consensus Fundamental algorithm question people solve How do we get agreement A version of this problem
Reach agreement on sequence.
We have a set of processes. Very much in the permission setting. Aren’t blockchains my def permissionless. Proof of stake.
Permission consensus relevant to blockchain research today
First consistency Everyone wants to see the same chain
Everyone wants to see the same chain.
Introducing adversaris Some subset of users are malicious.
On top of that network might be flaky.
On example what if someone
Difficult to achieve.
We don’t know which side is malicious.
Difficulty in solving.
Can we eliminate subtle voting rules that seem to be inherent to every consensus protocol.
Motivating simpler consensus protocol.
Goal simplest possible easy to understand consensus protocol.
Epochs Processes have local clocks, and run in synchronized epochs of 1 set of epochs.
2nd assumption Every epoch has a leader, a single leader known by all.
Definitions before meat of the protocol.
Block Notarized block Piece of the blockchain where all of the blocks are notarized
The streamlet protocol In every epoch… Leader- creates a new block Leader choose longest notarized chain Voters- signs the first block they see from the correct leader from the epoch they are in If and only if it extends the longest chain.
… Really, really simple. This is the meat of the finalization. This is our entire protocol. A leader proposes a block, extends the longest chain, then a voter votes on the block if it is indeed on the longest chain. Once he sees a few in a row, then he can finalize the entire chain. That’s it.
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