International Association for Cryptologic Research (IACR)
Abstract
Oblivious sorting is arguably the most important building block in the design of efficient oblivious algorithms. We propose new oblivious sorting algorithms for hardware enclaves. Our algorithms achieve asymptotic optimality in terms of both computational overhead and the number of page swaps the enclave has to make to fetch data from insecure memory or disk. We also aim to minimize the concrete constants inside the big-O. One of our algorithms achieve bounds tight to the constant in terms of the number of page swaps. We have implemented our algorithms and made them publicly available through open source. In comparison with (an unoptimized version of) bitonic sort, which is asymptotically non-optimal but the de facto algorithm used in practice, we achieve a speedup of 2000 times for 12 GB inputs
