Fig. 2. Secure and distributed reproduction of a survival-curve study.

a Survival curves generated in a centralized nonsecure manner and with FAMHE on the data used by Samstein et al.³⁰. TMB stands for tumor mutational burden. With FAMHE, the original data are split among three data providers, and the querier obtains exact results. The table in a displays the number of patients at risk at a specific time. The exact same numbers are obtained with the centralized, nonsecure solution and with FAMHE. b FAMHE execution time for the computation of one (or multiple) survival curve(s) with a maximum of 8192 time points. For both the aggregation and key switching (from the collective public key to the querier’s key), most of the execution time is spent in communication (up to 98%), as the operations on the encrypted data are lightweight and parallelized on multiple levels, i.e., among the data providers and among the encrypted values.