(PHP 5, PHP 7)
Raise an arbitrary precision number to another, reduced by a specified modulus
string bcpowmod ( string $left_operand, string $right_operand, string $modulus [, int $scale = 0 ] )
Use the fast-exponentiation method to raise left_operand to the power right_operand with respect to the modulus modulus.
Parameters:
left_operand
The left operand, as a string.