Feng-Hao Liu
Brown University

Tamper and Leakage Resilience in the Split-State Model

It is notoriously difficult to create hardware that is immune from side
channel and tampering attacks. A lot of recent literature, therefore,
has instead considered
algorithmic defenses from such attacks.

In this paper, we show how to algorithmically secure any cryptographic
functionality from continual split-state leakage and tampering
attacks. A split-state attack
on cryptographic hardware is one that targets separate parts of the
hardware separately. Our
construction does not require the hardware to have access to
randomness. On contrast, prior work
on protecting from continual combined leakage and tampering [KKS11]
required true randomness
for each update. Our construction is in the common reference string
(CRS) model; the CRS
must be hard-wired into the device. We note that prior negative
results show that it is
impossible to algorithmically secure a cryptographic functionality
against a combination of arbitrary
continual leakage and tampering attacks without true randomness;
therefore restricting our
attention to the split-state model is justified.

Our construction is simple and modular, and relies on a new construction,
in the CRS model, of non-malleable codes with respect to split-state tampering
functions, which may be of independent interest.

Joint work with:
Anna Lysyanskaya