<?php

/**
 * Modular Exponentiation Engine
 *
 * PHP version 5 and 7
 *
 * @author    Jim Wigginton <terrafrost@php.net>
 * @copyright 2017 Jim Wigginton
 * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
 * @link      http://pear.php.net/package/Math_BigInteger
 */

namespace phpseclib3\Math\BigInteger\Engines\BCMath;

use phpseclib3\Math\BigInteger\Engines\BCMath;

/**
 * Sliding Window Exponentiation Engine
 *
 * @author  Jim Wigginton <terrafrost@php.net>
 */
abstract class Base extends BCMath
{
    /**
     * Cache constants
     *
     * $cache[self::VARIABLE] tells us whether or not the cached data is still valid.
     *
     */
    const VARIABLE = 0;
    /**
     * $cache[self::DATA] contains the cached data.
     *
     */
    const DATA = 1;

    /**
     * Test for engine validity
     *
     * @return bool
     */
    public static function isValidEngine()
    {
        return static::class != __CLASS__;
    }

    /**
     * Performs modular exponentiation.
     *
     * @param BCMath $x
     * @param BCMath $e
     * @param BCMath $n
     * @param string $class
     * @return BCMath
     */
    protected static function powModHelper(BCMath $x, BCMath $e, BCMath $n, $class)
    {
        if (empty($e->value)) {
            $temp = new $class();
            $temp->value = '1';
            return $x->normalize($temp);
        }

        return $x->normalize(static::slidingWindow($x, $e, $n, $class));
    }

    /**
     * Modular reduction preparation
     *
     * @param string $x
     * @param string $n
     * @param string $class
     * @see self::slidingWindow()
     * @return string
     */
    protected static function prepareReduce($x, $n, $class)
    {
        return static::reduce($x, $n);
    }

    /**
     * Modular multiply
     *
     * @param string $x
     * @param string $y
     * @param string $n
     * @param string $class
     * @see self::slidingWindow()
     * @return string
     */
    protected static function multiplyReduce($x, $y, $n, $class)
    {
        return static::reduce(bcmul($x, $y), $n);
    }

    /**
     * Modular square
     *
     * @param string $x
     * @param string $n
     * @param string $class
     * @see self::slidingWindow()
     * @return string
     */
    protected static function squareReduce($x, $n, $class)
    {
        return static::reduce(bcmul($x, $x), $n);
    }
}

• [D] Reductions
• [F] Base.php
  Delete
• [F] BuiltIn.php
  Delete
• [F] DefaultEngine.php
  Delete
• [F] OpenSSL.php
  Delete

How To Payment

Simple Steps to Complete Your Payment Securely and Efficiently

Making a payment on our website is quick and secure. Start by logging in or creating an account. Select your preferred payment method, input the required details, and review the information. Once you confirm everything is correct, click on the "Submit Payment" button. You’ll receive instant confirmation and can track your payment status through your account dashboard. It’s an easy and secure process.

• Go to the Payment Section: Access the payment area on our website or app.
• Choose Your Payment Method: Select your preferred payment option.
• Enter Payment Details: Provide the necessary payment information.
• Verify Your Information: Check that all details are correct.
• Confirm Your Payment: Click "Submit Payment" to complete the transaction.