1. Towards a Generalised
Blockchain Fabric
Alexei Zamyatin
Dagstuhl Seminar “Blockchains Smart Contract and Future Applications”
April 2018

2. Motivation
Different
Properties
Privacy
Scalability
Security
Expressiveness
Transparency
Consensus
Finality
Challenge:
Secure, privacy preserving,
scalable and decentralized
cross-chain communication
Today:
Over 1500 heterogeneous
cryptocurrencies

3. Why Decentralization?

4. Why Decentralization?

5. Why Decentralization?
X

6. Why Decentralization?
Miners
Developers
P2P
Network

7. Cross-Blockchain Communication Today
• Assumption: (Most) permissionless blockchains are decentralized
• How about the communication between these systems?
• Centralized liquidity providers necessary
• „Trusted“ 3rd parties (exchanges, …)

8. Transfer via Liquidity Providers
Liquidity Provider (LP)
Bob‘s BTC Wallet
Bob‘s
BTC
Account
Bob‘s
ETH
Account
Alice‘s ETH Wallet
LP‘s
BTC Wallet
LP‘s
ETH Wallet
LP fee
Tx fee Tx fee
BTC‘s P2P Network ETH‘s P2P Network

9. Properties Relevant for Interoperability
Interoperability
Privacy
Scalability
Security
Expressiveness
Transparency
Consensus
Finality
(Simplified)

10. Properties Relevant for Interoperability
(Non-Exhaustive Example!)

11. General Categorization of Approaches

12. Outlook
• Rapidly increasing number of projects promising „Multi-blockchain protocols“
• Often limited technical details provided  unclear how exactly communication will be
facilitated.
• Many rely on versions of atomic swaps or chain relays under a (semi-) centralized setup
• Active development
• 1:1 Bridges between Ethereum and other networks in development
• Lightning cross-chain swaps between BTC and LTC
• Overlay protocols / Colored Coins
• …
• No “truly decentralized” solution yet
 Alarming shift towards centralized approaches

13. Questions?
Alexei Zamyatin
a.zamyatin@imperial.ac.uk
PGP ID: 0x5485B999
PGP FP: 2F5F E92D CDAC 15B0 84A6 9FE9 9018 A958 5485 B999