redacted-ts

redacted-ts

Redacting classified documents

This repository holds the code base for my redacted-ts library in TypeScript as well as its companion CLI: redacted-cli.
It is mainly based off my Feistel cipher for Format-Preserving Encryption to which I added a few tools to handle document, database and file manipulation to ease out the operation.

Motivation

In some fields (like healthcare for instance), protecting the privacy of data whilst being able to conduct in-depth studies is both vital and mandatory. Redacting documents and databases is therefore the obligatory passage. With redacted-ts, I provide a simple yet secure tool to help redacting documents based on either a dictionary, a record layout or a tag to decide which parts should actually be redacted.

Usage

You can use either a dictionary or a tag (or both) to identify the words you want to redact in a document. The tag should be placed before any word that should be redacted. The default tag is the tilde character (~).

For example, the following sentence will only see the word tagged redacted: "This is a ~tagged sentence".

$ npm install redacted-ts

import { DefaultRedactor, Dictionary } from 'redacted-ts'
import { FPECipher, SHA_256 } from 'feistel-cipher'

const source = 'Some text ~tagged or using words in a dictionary'

const cipher = new FPECipher(SHA_256, key, 10)
const redactor = DefaultRedactor(cipher)
const redacted = redactor.redact(source)

const expanded = redactor.expand(redacted)
assert(expanded === source)

const cleansed = redactor.clean(expanded)
assert(cleansed === 'Some text tagged or using words in a dictionary')

CLI

You can also install it globally and use it as a CLI for handling files:

$ npm i -g redacted-cli
$ redacted -V

$ redacted --help
  ____          _            _           _ 
 |  _ \ ___  __| | __ _  ___| |_ ___  __| |
 | |_) / _ \/ _` |/ _` |/ __| __/ _ \/ _` |
 |  _ <  __/ (_| | (_| | (__| ||  __/ (_| |
 |_| \_\___|\__,_|\__,_|\___|\__\___|\__,_|
                                           
Usage: redacted [options]

A TypeScript-based CLI to redacting classified documents

Options:
  -V, --version             output the version number
  -b, --both                add to use both dictionary and tag
  -d, --dictionary <value>  the optional path to the dictionary of words to redact
  -H, --hash <value>        the hash engine for the round function (default "sha-256")
  -i, --input <value>       the path to the document to be redacted
  -k, --key <value>         the optional key for the FPE scheme (leave it empty to use default)
  -o, --output <value>      the name of the output file
  -r, --rounds <value>      the number of rounds for the Feistel cipher (default 10)
  -t, --tag <value>         the optional tag that prefixes words to redact (default "~")
  -x, --expand              add to expand a redacted document
  -h, --help                display help for command

NB: The dictionary file must consist of space-separated words.

License

The use of the redacted libraries and executables are subject to fees for commercial purpose and to the respect of the BSD-2-Clause-Patent license.
Please contact me to get further information.

NB: It is still under development so use in production at your own risk for now.

© 2021-2025 Cyril Dever. All rights reserved.