# Universal Encryption of Individual Sequences Under Maximal Information Leakage

## TL;DR

This paper explores how to encrypt individual data sequences to minimize information leakage using a specific mathematical framework.

## Contribution

The paper introduces a method combining Lempel–Ziv compression and one-time pad encryption to achieve minimal information leakage.

## Key findings

- A lower bound and an asymptotically matching upper bound on maximal information leakage are derived.
- Lempel–Ziv compression followed by one-time pad encryption minimizes leakage asymptotically.

## Abstract

We consider the Shannon cipher system in the framework of individual sequences and finite-state encrypters under the metric of maximal information leakage. A lower bound and an asymptotically matching upper bound on the leakage are derived, which lead to the conclusion that asymptotically minimum leakage can be attained by Lempel–Ziv compression followed by one-time pad encryption of the compressed bitstream.