  Privacy-preserving data aggregation in ad hoc networks is a challenging
problem, considering the distributed communication and control requirement,
dynamic network topology, unreliable communication links, etc. Different from
the widely used cryptographic approaches, in this paper, we address this
challenging problem by exploiting the distributed consensus technique. We first
propose a secure consensus-based data aggregation (SCDA) algorithm that
guarantees an accurate sum aggregation while preserving the privacy of
sensitive data. Then, we prove that the proposed algorithm converges accurately
and is $(\epsilon, \sigma)$-data-privacy, and the mathematical relationship
between $\epsilon$ and $\sigma$ is provided. Extensive simulations have shown
that the proposed algorithm has high accuracy and low complexity, and they are
robust against network dynamics.
