gmp_powm

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

gmp_powm — Raise number into power with modulo

gmp_powm(GMP|int|string $num, GMP|int|string $exponent, GMP|int|string $modulus): GMP

Calculate (num raised into power exponent) modulo modulus. If exponent is negative, result is undefined.

num: The base number.
A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init() with automatic base detection (i.e. when base is equal to 0).
exponent: The positive power to raise the num.
A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init() with automatic base detection (i.e. when base is equal to 0).
modulus: The modulo.
A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init() with automatic base detection (i.e. when base is equal to 0).

The new (raised) number, as a GMP number.

Example #1 gmp_powm() example

<?php
$pow1 = gmp_powm("2", "31", "2147483649");
echo gmp_strval($pow1) . "\n";
?>

The above example will output:

2147483648

down

7 years ago

can be used for RSA encryption/decryption!