// function to generate homoglyphed watermark string

generateHomoglyphedString.php

// function to generate homoglyphed watermark string
<?php
function generateRandomWatermark(){
  $char_d = array("d","ď","đ","ԁ","ժ","ḍ","ⅾ","ｄ");
  $char_x = array("x","χ","х","ⅹ","ｘ");
  $char_m = array("m","ⅿ","ｍ");
  $char_e = array("e","é","ê","ë","ē","ĕ","ė","ě","е","ｅ");
  $char_k = array("k","κ","ｋ");
  $char_c = array("c","ϲ","с","ⅽ","ｃ");
  $char_h = array("h","һ","ｈ");
  $char_Em_d = array("Ď","Đ","Ꭰ","Ⅾ","Ｄ");
  $char_Em_x = array("X","Χ","Х","Ⅹ","Ｘ");
  $char_Em_m = array("M","Μ","Ϻ","М","Ꮇ","ᛖ","Ⅿ","Ｍ");
  $char_Em_e = array("E","È","É","Ê","Ë","Ē","Ĕ","Ė","Ę","Ě","Ε","Е","Ꭼ","Ｅ");
  $char_Em_k = array("K","Κ","К","Ꮶ","ᛕ","K","Ｋ");
  $char_Em_c = array("C","Ϲ","С","Ꮯ","Ⅽ","Ｃ");
  $char_Em_h = array("H","ʜ","Η","Н","Ꮋ","Ｈ");
  $char_dots = array(".","․","．");

  $gen_watermark = "&copy; ";
  if(rand(0,100) > 50){
    $gen_watermark .= $char_d[rand(0, sizeof($char_d) - 1)];
    $gen_watermark .= $char_x[rand(0, sizeof($char_x) - 1)];
    $gen_watermark .= $char_m[rand(0, sizeof($char_m) - 1)];
    $gen_watermark .= $char_e[rand(0, sizeof($char_e) - 1)];
    $gen_watermark .= $char_k[rand(0, sizeof($char_k) - 1)];
    $gen_watermark .= $char_dots[rand(0, sizeof($char_dots) - 1)];
    $gen_watermark .= $char_c[rand(0, sizeof($char_c) - 1)];
    $gen_watermark .= $char_h[rand(0, sizeof($char_h) - 1)];
  } else {
    $gen_watermark .= $char_Em_d[rand(0, sizeof($char_Em_d) - 1)];
    $gen_watermark .= $char_Em_x[rand(0, sizeof($char_Em_x) - 1)];
    $gen_watermark .= $char_Em_m[rand(0, sizeof($char_Em_m) - 1)];
    $gen_watermark .= $char_Em_e[rand(0, sizeof($char_Em_e) - 1)];
    $gen_watermark .= $char_Em_k[rand(0, sizeof($char_Em_k) - 1)];
    $gen_watermark .= $char_dots[rand(0, sizeof($char_dots) - 1)];
    $gen_watermark .= $char_Em_c[rand(0, sizeof($char_Em_c) - 1)];
    $gen_watermark .= $char_Em_h[rand(0, sizeof($char_Em_h) - 1)];
  }
  return $gen_watermark;
}
?>

mb_generateHomoglyphedString.php

<?php

// function to generate homoglyphed watermark string
function generateRandomWatermark(){
  $char_d = "dďđԁժḍⅾｄ";
  $char_x = "xχхⅹｘ";
  $char_m = "mⅿｍ";
  $char_e = "eéêëēĕėěеｅ";
  $char_k = "kκｋ";
  $char_c = "cϲсⅽｃ";
  $char_h = "hһｈ";
  $char_Em_d = "ĎĐᎠⅮＤ";
  $char_Em_x = "XΧχХⅩＸ";
  $char_Em_m = "MΜϺМᎷᛖⅯＭ";
  $char_Em_e = "EÈÉÊËĒĔĖĘĚΕЕᎬＥ";
  $char_Em_k = "KΚКᏦᛕKＫ";
  $char_Em_c = "CϹСᏟⅭＣ";
  $char_Em_h = "HʜΗНᎻＨ";
  $char_dots = ".․．";

  $gen_watermark = "";
  if(rand(0,100) > 50){
    $gen_watermark .= mb_substr($char_d, rand(0, mb_strlen($char_d) - 1), 1);
    $gen_watermark .= mb_substr($char_x, rand(0, mb_strlen($char_x) - 1), 1);
    $gen_watermark .= mb_substr($char_m, rand(0, mb_strlen($char_m) - 1), 1);
    $gen_watermark .= mb_substr($char_e, rand(0, mb_strlen($char_e) - 1), 1);
    $gen_watermark .= mb_substr($char_k, rand(0, mb_strlen($char_k) - 1), 1);
    $gen_watermark .= ".";
    $gen_watermark .= mb_substr($char_c, rand(0, mb_strlen($char_c) - 1), 1);
    $gen_watermark .= mb_substr($char_h, rand(0, mb_strlen($char_h) - 1), 1);
  } else {
    $gen_watermark .= mb_substr($char_Em_d, rand(0, mb_strlen($char_Em_d) - 1), 1);
    $gen_watermark .= mb_substr($char_Em_x, rand(0, mb_strlen($char_Em_x) - 1), 1);
    $gen_watermark .= mb_substr($char_Em_m, rand(0, mb_strlen($char_Em_m) - 1), 1);
    $gen_watermark .= mb_substr($char_Em_e, rand(0, mb_strlen($char_Em_e) - 1), 1);
    $gen_watermark .= mb_substr($char_Em_k, rand(0, mb_strlen($char_Em_k) - 1), 1);
    $gen_watermark .= ".";
    $gen_watermark .= mb_substr($char_Em_c, rand(0, mb_strlen($char_Em_c) - 1), 1);
    $gen_watermark .= mb_substr($char_Em_h, rand(0, mb_strlen($char_Em_h) - 1), 1);
  }
  return $gen_watermark;
}

?>