Abstract
Entropically Secure Encryption (ESE) offers unconditional security with
shorter keys compared to the One-Time Pad. In this paper, we present the
first implementation of ESE for bulk encryption. The main computational
bottleneck for bulk ESE is a multiplication in a very large finite
field. This involves multiplication of polynomials followed by modular
reduction. We have implemented polynomial multiplication based on the
gf2x library, with some modifications that avoid inputs of vastly
different length, thus improving speed. Additionally, we have
implemented a recently proposed efficient reduction algorithm that works
for any polynomial degree. We investigate two use cases: X-ray images of
patients and human genome data. We conduct entropy estimation using
compression methods whose results determine the key lengths required for
ESE. We report running times for all steps of the encryption. We discuss
the potential of ESE to be used in conjunction with Quantum Key
Distribution (QKD), in order to achieve full information-theoretic
security of QKD-protected links for these use cases.