Mobile blockchain transactions require low latency
for practical deployment. This paper presents a
smartphone-native Trustchain system developed as
part of a collaborative research project where five
students implement Trustchain from scratch, each
optimizing a different performance metric: latency,
robustness, storage, throughput, and battery effi-
ciency. This work focuses on latency optimiza-
tion through a novel modular architecture imple-
mented in Rust/Kotlin that enables runtime proto-
col switching—the first such capability in mobile
blockchain implementations.
The evaluation compares two transport layers: a
lightweight UDP implementation and a business-
grade P2P solution (Iroh). Testing on Android de-
vices demonstrates end-to-end round-trip laten-
cies from 11.8 ms under optimal conditions to
240 ms at extreme loads (500 MPS), with UDP
achieving consistent 11.8ms median latency and
Iroh showing 18.2ms for typical payloads. Results
show clear trade-offs between protocol complexity
and performance, providing guidance for selecting
transport mechanisms in different mobile deploy-
ment scenarios. All code is released open-source to
the Tribler project for reproducibility.