English

Locks and keys: How fast can you open several locks with too many keys?

History and Overview 2015-09-04 v1 Cryptography and Security Probability

Abstract

This short note is the result of a French "Hippocampe internship" that aims at introducing the world of research to young undergraduate French students. The problem studied is the following: imagine yourself locked in a cage barred with nn different locks. You are given a keyring with NnN \geq n keys containing the nn keys that open the locks. In average, how many trials are required to open all locks and get out? The article studies 33 different strategies and compare them. Implementation of the strategies are also proposed as illustrations of the theoretical results.

Keywords

Cite

@article{arxiv.1509.00844,
  title  = {Locks and keys: How fast can you open several locks with too many keys?},
  author = {Olivier Marchal},
  journal= {arXiv preprint arXiv:1509.00844},
  year   = {2015}
}

Comments

12 pages, 6 figures. To be read essentially for fun