northlands/permuteseq

A small PHP library to obfuscate numbers.

v0.2 2022-09-05 10:28 UTC

Requires

• php: ^8.1|^8.0

Requires (Dev)

• pestphp/pest: ^1.21
• phpstan/extension-installer: ^1.1
• phpstan/phpstan-deprecation-rules: ^1.0
• phpstan/phpstan-phpunit: ^1.0
• phpunit/phpunit: ^9.5

MIT

• Martin Skovvang Petersen

• permutation
• obfuscation
• fiestel

README

A small PHP library to obfuscate numbers. Use it when you don't want to expose your database numeric ids to users.

The permutations are collision-free and fully deterministic. The random-looking effect is due to encryption, not to a PRNG. The same boundary range with the same secret key will always produce the same output.

Installation

You can install the package via composer:

composer require northlands/permuteseq

Usage

$permuteseq = new Permuteseq(123456789012345, 1000, 9999); // Range 1000-9999

$encoded = $permuteseq->encode(1000); // 1446
$decoded = $permuteseq->decode($encoded); // 1000

Testing

composer test

In order to ensure compability with the Postgres extension, an integration test is included:

vendor/bin/pest --group=integration

The integration test requires a running Postgres database with the extension installed:

docker build -t postgres tests
docker run --name postgres -p 5432:5432 -e POSTGRES_PASSWORD=local -d postgres

psql> CREATE EXTENSION permuteseq;

Changelog

Please see CHANGELOG for more information on what has changed recently.

Disclaimer

The library should not be considered cryptographically strong or used to sensitive data.

Credits

• https://github.com/dverite/permuteseq
  The PostgreSQL extension by Daniel Vérité.

• https://czep.net/21/obfuscate.html
  An article on how to obfuscate primary keys in databases.

Alternatives

• https://github.com/ioleo/cryptomute
  Another Format Preserving Encryption library supporting multiple ciphers (DES, AES and Camellia) but slower performance.

• https://github.com/vinkla/hashids
  Generates YouTube-like ids from numbers. Can be limited to digit-alphabet, but returns strings like "09284" instead of safe integers.

• https://github.com/jenssegers/optimus
  Super-fast number obfuscation based on Knuth's integer hash. However, range can only be defined by 4-62 bits.

License

The MIT License (MIT). Please see License File for more information.