Faster Homomorphic Evaluation of Discrete Fourier Transforms

@article{Costache2016FasterHE,
  title={Faster Homomorphic Evaluation of Discrete Fourier Transforms},
  author={Anamaria Costache and Nigel P. Smart and Srinivas Vivek},
  journal={IACR Cryptology ePrint Archive},
  year={2016},
  volume={2016},
  pages={1019}
}
We present a methodology to achieve low latency homomorphic operations on approximations to complex numbers, by encoding a complex number as an evaluation of a polynomial at a root of unity. We then use this encoding to evaluate a Discrete Fourier Transform (DFT) on data which has been encrypted using a Somewhat Homomorphic Encryption (SHE) scheme, with up to three orders of magnitude improvement in latency over previous methods. We are also able to deal with much larger input sizes than… CONTINUE READING