  Data security and availability for operational use are frequently seen as
conflicting goals. Research on searchable encryption and homomorphic encryption
are a start, but they typically build from encryption methods that, at best,
provide protections based on problems assumed to be computationally hard. By
contrast, data encoding methods such as secret sharing provide
information-theoretic data protections. Archives that distribute data using
secret sharing can provide data protections that are resilient to malicious
insiders, compromised systems, and untrusted components.
  In this paper, we create the Serial Interpolation Filter, a method for
storing and interacting with sets of data that are secured and distributed
using secret sharing. We provide the ability to operate over set-oriented data
distributed across multiple repositories without exposing the original data.
Furthermore, we demonstrate the security of our method under various attacker
models and provide protocol extensions to handle colluding attackers. The
Serial Interpolation Filter provides information-theoretic protections from a
single attacker and computationally hard protections from colluding attackers.
