  Topological Data Analysis (TDA) offers a suite of computational tools that
provide quantified shape features in high dimensional data that can be used by
modern statistical and predictive machine learning (ML) models. In particular,
persistent homology (PH) takes in data (e.g., point clouds, images, time
series) and derives compact representations of latent topological structures,
known as persistence diagrams (PDs). Because PDs enjoy inherent noise
tolerance, are interpretable and provide a solid basis for data analysis, and
can be made compatible with the expansive set of well-established ML model
architectures, PH has been widely adopted for model development including on
sensitive data, such as genomic, cancer, sensor network, and financial data.
Thus, TDA should be incorporated into secure end-to-end data analysis
pipelines. In this paper, we take the first step to address this challenge and
develop a version of the fundamental algorithm to compute PH on encrypted data
using homomorphic encryption (HE).
