Sharing a Secret (UMAP)

This module considers the problem of devising a scheme for predesignated subsets of a group of people to hold a secret jointly (each knowing just a part), without other subsets being able to discover the secret. The problem has applications to many areas where shared responsibility for security and decision-making is important, such a banking (the vault combination), commerce (trade secrets), and warfare (weapons launching). A proof of the Chinese Remainder Theorem along with a generalization of it are included in this module.

Table of Contents:

INTRODUCTION

THE CHINESE REMAINDER THEOREM

A MORE GENERAL FORM OF THE CRT

A THRESHOLD SCHEME

ASYMMETRICAL SHARING

INFORMATION

SOLUTIONS TO THE EXERCISES

REFERENCES

ABOUT THE AUTHOR