TRUST WITHOUT EXPOSURE: VERIFIABLEOBSERVABILITY WITH CAPABILITY-NATIVEWEBASSEMBLY AT THE EDGE

<p>In modern data ecosystems, where edge autonomy, privacy, and verifiability are essential, enablingtrustworthy observability without compromising data control remains a significant challenge. This paper presents cWAMR, a capability-native WebAssembly runtime adapted for the CHERI (CapabilityHardware Enhanced RISC Instructions) architecture, enabling fine-grained, hardware-enforcedcompartmentalization of untrusted code.<br>We demonstrate how cWAMR enables the construction of Verifiable Observability Pipelines (VoP)—modular, staged execution flows deployed across edge environments. Each pipeline stage is implementedas an isolated WebAssembly module running in a CHERI-sealed cWAMR compartment, with capability- based delegation enforcing tamper-evident data flow and memory safety without shared linear memory or enclave-based trust models.<br>Deployed and validated on the Arm Morello platform under the UK DSbD initiative, cWAMR supports bothinterpreted and ahead-of-time WebAssembly execution, integrated with CHERI-aware systeminterfaces (cWASI). The result is a lightweight, privacy-aligned foundation for building observable, compliant edgepipelines—enabling cryptographically anchored provenance and lifecycle assurance without clouddependency or centralised attestation infrastructure.</p>