Space-efficient blockchains

Talk by Georg Fuchsbauer

2024-10-19

Location: TU Wien,
Date/Time: 2025-01-27 16:00 ‒ 17:00

Abstract: The move from “proof of work” to “proof of stake” has arguably overcome the problem of energy waste in blockchains. However, for public verifiability, most systems require all transactions to be stored forever, by every full node. In Bitcoin this data now amounts to over 600GB, while in Ethereum it is over 1TB. We will overview two approaches to space-efficient systems. “Mimblewimble” is a protocol where spent transactions can be erased from the blockchain while maintaining verifiability. “Mina” goes further and, using a heavy-weight cryptographic concept called zk-SNARK, reduces its blockchain size to 22kB, which will never grow.

The talk is a part of the Public Lecture Series ‘Sustainability in Computer Science’ under the auspices of Informatik Austria.