  Asynchronous Byzantine Atomic Broadcast (ABAB) promises simplicity in
implementation as well as increased performance and robustness in comparison to
partially synchronous approaches. We adapt the recently proposed DAG-Rider
approach to achieve ABAB with $n\geq 2f+1$ processes, of which $f$ are faulty,
with only a constant increase in message size. We leverage a small Trusted
Execution Environment (TEE) that provides a unique sequential identifier
generator (USIG) to implement Reliable Broadcast with $n>f$ processes and show
that the quorum-critical proofs still hold when adapting the quorum size to
$\lfloor \frac{n}{2} \rfloor + 1$. This first USIG-based ABAB preserves the
simplicity of DAG-Rider and serves as starting point for further research on
TEE-based ABAB.
