Please note: This PhD seminar will be given online.
Eric
Dong, PhD
candidate
David
R.
Cheriton
School
of
Computer
Science
Supervisor: Professor Raouf Boutaba
Increasing usage of blockchain-based cryptocurrencies like Bitcoin and Ethereum have run into inherent scalability limitations of blockchains. Payment channels networks, or PCNs, promise to greatly increase scalability by conducting the vast majority of transactions outside the blockchain while leveraging it as a final settlement protocol. Unfortunately, currently deployed PCNs have significant flaws in security and privacy. In particular, even though transactions are conducted off-chain, anonymity guarantees are very weak.
In this work, we present Astrape, a novel PCN construction that achieves strong security and anonymity guarantees with simple, black-box cryptography. Existing anonymous PCN constructions all integrate with specific, often custom-designed, cryptographic constructions, but Astrape can use any generic public-key signature scheme and any random-oracle hash function. This allows Astrape to achieve provable security without relying on any specific computational hardness assumption. Astrape’s simple cryptography also lends itself to unusually straightforward security proofs compared to existing systems.
Furthermore, we evaluate Astrape’s performance, including that of a concrete implementation on the Bitcoin Cash blockchain. We show that on the average case, Astrape operations require less than 20 milliseconds of computation and 1 KB of communication on commodity hardware. Astrape explores a novel avenue to secure and anonymous PCNs that achieves similar or better performance compared to all existing solutions.
To join this PhD seminar on Zoom, please go to https://zoom.us/j/96852576305?pwd=eVhQVSt4MUxZcmp3TEFmV1g3NzU5dz09.