TU München - Fakultät für
Es sprechen Studenten Ã¼ber ihre abgeschlossenen Diplomarbeiten und Systementwicklungsprojekte.
Am Dienstag, 17.07.18, ab 14:00 Uhr, im Raum Neumann (00.11.038):
Simulation-Based Analysis of Blockchain Architectures
One of the most compelling arguments for blockchains based on proof of work is their inherent resistance against the retroactive modification of stored data. However, potential attacks on blockchain architectures enabling the modification of already confirmed blocks have been formulated in the past. The infamous âdouble-spend attackâ describes a group of dishonest nodes secretly mining new blocks on top of an altered block. After surpassing the proof of work contained in the honest chain, the secret branch is published and consequently accepted by the remaining network. According to Bitcoinâs Satoshi Nakamoto, such an attack requires the majority of computational power available to the network. Nevertheless, successful double-spend attacks using less computing power are possible and the resistance of blockchain architectures against these attacks depends on a variety of factors. To increase the understanding of these factors and improve an architects predictions of double-spend resistance, we will develop a simulator framework for blockchain architectures and conduct a range of experiments. By testing the effects of inter alia the topology and latency of the underlying peer-to-peer networks and the mining difficulty, we discover that especially the number of natural blockchain branches influences a networkâs mining power and therefore the resistance against double-spend attacks. The insights and data gathered throughout the experiments are finally summarized by the proposal of an empirical model describing the effects of all identified parameters on double-spend resistance.