  We propose Black-Box IoT (BBox-IoT), a new ultra-lightweight black-box system
for authenticating and storing IoT data. BBox-IoT is tailored for deployment on
IoT devices (including low-Size Weight and Power sensors) which are extremely
constrained in terms of computation, storage, and power. By utilizing core
Blockchain principles, we ensure that the collected data is immutable and
tamper-proof while preserving data provenance and non-repudiation. To realize
BBox-IoT, we designed and implemented a novel chain-based hash signature scheme
which only requires hashing operations and removes all synchronicity
dependencies between signer and verifier. Our approach enables low-SWaP devices
to authenticate removing reliance on clock synchronization. Our evaluation
results show that BBox-IoT is practical in Industrial Internet of Things (IIoT)
environments: even devices equipped with 16MHz micro-controllers and 2KB memory
can broadcast their collected data without requiring heavy cryptographic
operations or synchronicity assumptions. Finally, when compared to industry
standard ECDSA, our approach is two and three orders of magnitude faster for
signing and verification operations respectively. Thus, we are able to increase
the total number of signing operations by more than 5000% for the same amount
of power.
