https://stackoverflow.com/questions/59355527/

composer.json

{
    "require": {
        "awkwardideas/phpcfencrypt": "^1.1"
    }
}

composer.lock

{
    "_readme": [
        "This file locks the dependencies of your project to a known state",
        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
        "This file is @generated automatically"
    ],
    "content-hash": "a2b2ed12414c4d70079aa4035b2581c0",
    "packages": [
        {
            "name": "awkwardideas/phpcfencrypt",
            "version": "1.1.0",
            "source": {
                "type": "git",
                "url": "https://github.com/awkwardideas/PHPCFEncrypt.git",
                "reference": "bcc8793f4a451705cdc5e43e9a1745d3044d1451"
            },
            "dist": {
                "type": "zip",
                "url": "https://api.github.com/repos/awkwardideas/PHPCFEncrypt/zipball/bcc8793f4a451705cdc5e43e9a1745d3044d1451",
                "reference": "bcc8793f4a451705cdc5e43e9a1745d3044d1451",
                "shasum": ""
            },
            "require": {
                "php": ">=7.0"
            },
            "require-dev": {
                "mockery/mockery": "^0.9.4",
                "phpunit/phpunit": "~6.0"
            },
            "type": "library",
            "autoload": {
                "psr-4": {
                    "AwkwardIdeas\\PHPCFEncrypt\\": "src/"
                }
            },
            "notification-url": "https://packagist.org/downloads/",
            "license": [
                "MIT"
            ],
            "authors": [
                {
                    "name": "Chad Haney",
                    "email": "chad@awkwardideas.com"
                },
                {
                    "name": "Awkward Ideas",
                    "email": "support@awkwardideas.com"
                }
            ],
            "description": "PHP functions for performing ColdFusion encrypt",
            "time": "2017-09-22T05:16:57+00:00"
        }
    ],
    "packages-dev": [],
    "aliases": [],
    "minimum-stability": "stable",
    "stability-flags": [],
    "prefer-stable": false,
    "prefer-lowest": false,
    "platform": [],
    "platform-dev": []
}

main.php

<?php
require __DIR__ . '/vendor/autoload.php';

use AwkwardIdeas\PHPCFEncrypt\Encrypt;

$stringToDecrypt = '6A968A969DEB9A16549C61EE2EFE40A6515E';
$key = '2450RDSET0C';
$decrypted = Encrypt::decrypt($stringToDecrypt, $key, 'CFMX_COMPAT', 'hex');
var_dump($decrypted);