Paper 2020/715

On (impracticality of) transfinite symmetric encryption with keys smaller than messages under GCH

Sergij V. Goncharov

Abstract

In this short trivial note we argue that, assuming Generalized Continuum Hypothesis to be true, it is impractical to use encryption with $Key \in \{ 0, 1 \}^K$ and $Message \in \{ 0, 1 \}^M$ such that $\aleph_0 \leqslant \mathrm{card}\,K < \mathrm{card}\,M$, because "complexity" of the known-plaintext bruteforce attack equals "complexity" of a single $En/Decrypt(Key, Message)$ "computation" then.