One Time Pad and the Short Key Dream

TL;DR

This survey explores the history, principles, and challenges of the One Time Pad (OTP), emphasizing the importance of generating long, truly random sequences from short keys, and discusses related issues in randomness and cryptography.

Contribution

It provides a comprehensive overview of OTP, its theoretical foundations, practical challenges, and a vast bibliography on related topics like randomness and pseudorandom generators.

Findings

OTP is unbreakable if used correctly.

Generating long true random sequences from short keys is complex.

The survey compiles extensive references on randomness and cryptography.

Abstract

This is a survey on the One Time Pad (OTP) and its derivatives, from its origins to modern times. OTP, if used correctly, is (the only) cryptographic code that no computing power, present or future, can break. Naturally, the discussion shifts to the creation of long random sequences, starting from short ones, which can be easily shared. We could call it the Short Key Dream. Many problems inevitably arise, which affect many fields of computer science, mathematics and knowledge in general. This work presents a vast bibliography that includes fundamental classical works and current papers on randomness, pseudorandom number generators, compressibility, unpredictability and more.