Building Usable Witness Encryption

TL;DR

This paper advances witness encryption by implementing a new ciphertext encoding using multilinear maps, demonstrating practical encryption of Bitcoin wallet keys through a Sudoku-based scheme.

Contribution

It introduces the first ciphertext encoding with a candidate witness encryption scheme based on an open-source multilinear map implementation.

Findings

Successfully encoded ciphertext with witness encryption scheme

Encrypted Bitcoin wallet private key using Sudoku puzzle

Demonstrated practical application of witness encryption in cryptocurrency security

Abstract

Witness encryption using multilinear maps was first proposed in 2013, and has continued to evolve since. In this paper, we build on an open-source multilinear map implementation by Carmer and Malozemoff of the graded encoding scheme CLT13 with asymmetric modifications. Using this map, we created the world's first ciphertext encoded with a candidate witness encryption scheme. Finally, using a reduction from Sudoku to Exact Cover, we encrypted the private key to a Bitcoin wallet with 22,700 Satoshi using a Sudoku.