This is very ugly code that solves the php[magazine] puzzle of the month for May 2021

Polybius Cipher

<?php

$chars = array_merge(range('a', 'z'), range('A','Z'), range(0,9), [' ', ',', "'"]);
shuffle($chars);

$table = [];
$header = '     ';
foreach (range(1,8) as $row) {
	$header .= " $row  ";
	$table[$row] = array_slice($chars, ($row-1)*8, 8);
}

	print "   " . $header . "\n";
foreach ($table as $row => $col) {
	print "    $row    ";
	print implode($col, "   ");
	print "\n";
}


$message = "Let's Record A Podcast";
print $message . "\n";
$cipher = encrypt($message, $table);
print $cipher . "\n";

$decrypted = decrypt($cipher, $table);
print $decrypted . "\n";

function encrypt($message, $table) {
	$chars = str_split($message);
	$cipher = '';
	foreach ($chars as $char) {
		$cipher .= find_coords($table, $char);
	}
	return $cipher;
}

function find_coords($table, $char) {
	foreach ($table as $row => $col) {
			if (in_array($char, $col)) {
				foreach ($col as $pos => $check) {
					if ($check === $char) {
						return $row . $pos + 1;
					}
				}
			}
	}
	return "|$char|";
}

function decrypt($message, $table) {
	$coords = str_split($message, 2);
	$decrypted = '';
	foreach ($coords as $coord) {
		[$row, $col] = str_split($coord);
		$decrypted .= $table[$row][$col-1];
	}
	return $decrypted;
}