Where the encryption is done, you should free the encryption buffers by calling mcrypt_generic_deinit().
?php $iv_size = mcrypt_enc_get_iv_size ($td)); $iv = @mcrypt_create_iv ($iv_size, MCRYPT_RAND); if (@mcrypt_generic_init ($td, $key, $iv) != -1) {$c_t = mcrypt_generic ($td, $plain_text); @mcrypt_generic_init ($td, $key, $iv); $p_t = mdecrypt_generic ($td, $c_t);} if (strncmp ($p_t, $plain_text, strlen($plain_text)) == 0) echo "ok"; else echo "erreur";?