<?php
/* Коды для замены букв */
'а' => '1',
'б' => '2',
'в' => '3',
'г' => '4',
'д' => '5',
'е' => '6',
'ё' => '7',
'ж' => '8',
'з' => '9',
'и' => '0',
'й' => '#',
' ' => '43',
'н' => '384',
'c' => '28',
'п' => '460',
'р' => '24',
'л' => '113',
'я' => '34'
);
$text = '3841с43460246511130.43343к14346024о3111363841';
$cipher = strtr($text , $code);
echo "Оригинал: {$text}\nШифровка: {$cipher}\n";
?>
PD9waHAKCmVycm9yX3JlcG9ydGluZygtMSk7CgovKiDQmtC+0LTRiyDQtNC70Y8g0LfQsNC80LXQvdGLINCx0YPQutCyICovCiRjb2RlID0gYXJyYXkoCiAgICAn0LAnCT0+CScxJywKICAgICfQsScJPT4JJzInLAogICAgJ9CyJwk9PgknMycsCiAgICAn0LMnCT0+CSc0JywKICAgICfQtCcJPT4JJzUnLAogICAgJ9C1Jwk9PgknNicsCiAgICAn0ZEnCT0+CSc3JywKICAgICfQticJPT4JJzgnLAogICAgJ9C3Jwk9PgknOScsCiAgICAn0LgnCT0+CScwJywKICAgICfQuScJPT4JJyMnLAogICAgJyAnID0+ICAnNDMnLAogICAgJ9C9JyA9PiAnMzg0JywKICAgICdjJyA9PiAnMjgnLAogICAgJ9C/JyA9PiAnNDYwJywKICAgICfRgCcgPT4gJzI0JywKICAgICfQuycgPT4gJzExMycsCiAgICAn0Y8nID0+ICczNCcKICAgIAopOwokY29kZSA9IGFycmF5X2ZsaXAoJGNvZGUpOwokdGV4dCA9ICczODQx0YE0MzQ2MDI0NjUxMTEzMC40MzM0M9C6MTQzNDYwMjTQvjMxMTEzNjM4NDEnOwokY2lwaGVyID0gc3RydHIoJHRleHQgLCAkY29kZSk7CgplY2hvICLQntGA0LjQs9C40L3QsNC7OiB7JHRleHR9XG7QqNC40YTRgNC+0LLQutCwOiB7JGNpcGhlcn1cbiI7Cj8+