blockchains –from technology to use cases · blockchains –from technology to use cases björn...
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Blockchains – From technology to use casesBjörn Tackmann – IBM Research – Zurich – [email protected]
2Decentralization and trust
Decentralized transaction processing
3
• Every node verifies transaction• Nodes find consensus on whether
to include transaction in chain• Consensus needs assumptionsSender
Network of verifiers
Bitcoin mining
4
Satoshi’s idea
“One CPU, one vote!”
The reality
Mining farms in countries with low energy costMining pools to better distribute rewards
6 large pools have 80% capacity
more then 75% of capacity in one country
one manufacturer with 75% market share
Alternative trust models
5
Proof of stake consensus Permissioned consensus
Use case: Public land registry
6
How much do you trust authorities?How much do you trust a blockchain?
Current system: trust acentral authority!
UNDP pilot, store informationon Ethereum blockchain!
Trust in infrastructure and devices
7
8Confidentiality and privacy
A public ledger is … public!
Supply chain networks
10
Bank A Bank B
Producer B Shop D
Transporter 1
Producer A Consumer C
Warehouse 1
Transporter 2
Warehouse 2Transporter 3
Sharing your apartment via blockchain11
SolutionsEither use access control …
… or advanced cryptography.
13Tokenizing the world
How do I store a gold bar on a blockchain?
Use cases
15Stab
leco
ins
Phar
mac
eutic
als
Min
eral
s m
inin
g
Blockchain scaling is about finding the best trade-off!