  This paper studies anonymous and confidential genomic case and control
computing within the federated framework leveraging SPDZ. Our contribution
mainly comprises the following three-fold:
  \begin{itemize} \item In the first fold, an efficient construction of Beaver
triple generators (BTGs) formalized in the 3-party computation leveraging
multiplicatively homomorphic key management protocols (mHKMs) is presented and
analysed. Interestingly, we are able to show the equivalence between BTGs and
mHKMs. We then propose a lightweight construction of BTGs, and show that our
construction is secure against semi-honest adversary if the underlying
multiplicatively homomorphic encryption is semantically secure.
  \item In the second fold, a decoupling model for SPDZ with explicit
separation of BTGs from MPC servers (MPCs) is introduced and formalized, where
BTGs aim to generate the Beaver triples while MPCs to process the input data. A
new notion, which we call blind triple dispensation protocol, is then
introduced for securely dispensing the generated Beaver triples, and
constructed from mHKMs. We demonstrate the power of mHKMs by showing that it is
a useful notion not only for generating Beaver triples but also for securely
dispensing triples as well.
  \item In the third-fold, a lightweight genomic case and control computing
model is proposed, which reaches the anonymity and confidentiality
simultaneously. An efficient truncation algorithm leveraging the depicted BTGs
above is then proposed by eliminating computational cost heavy PRandBitL() and
PRandInt() protocols involved in the state-of-the-art solutions and thus
largely benefits us computing residual vectors for industrial scale deployment.
