Turn leadership mistakes into a better future.pptx
Some Open Problems in Blockchains
1. Moscow Blockchain Devs Meetup
Some Open Problems in Blockchains
Alexander Chepurnoy
(aka kushti)
@chepurnoy
IOHK Research
2. Background
● programming since 1996
● p2p systems with Scala/Akka
● Nxt core developer
● Consensus Research
● smartcontract.com cofounder(left)
● Scorex since late 2014
● IOHK Research
3. The talk is about
● What are open problems in blockchains
● How can we solve them
4. Current State
● 1.33 well understood systems working
● Bitcoin
● partly Ethereum
● A lot of work-in-progress around
6. Troughput (TPS)
● 7 ??? no
● 2-3 in fact
● 1/600 in worse case
https://www.reddit.com/r/Bitcoin/comments/3cgft7/largest_trans
7. Bitcoin Consensus Protocol
● „The Bitcoin Backbone Protocol:Analysis and Applications“
● „Analysis of the Blockchain Protocol in Asynchronous
Networks“
8. Better PoW
● Equihash - memory-hard PoW (ZCash)
● Permacoin – proofs of retrievability for static dataset
● Rollerchain – proofs of posession of state snapshots
11. Rollerchain
● Only last n full blocks to be stored collectively
● and n state snapshots
● Each miner stores k state snapshots
12. Rollerchain
● New node can download a historical snapshot
● Fullblocks not needed for mining could be thrown away
● Blockheaders are to be stored forever, so must be small
17. Anonymity
● A lot of schemes proposed
● Most of them are probably broken or not practical
● Cryptonote
● ZCash
● Upcoming survey from Bernardo David