Encryption failing

Hey --- - - I am in the process of upgrading the encryption technology I am using from (64 bit) blowfish to (256 bit) rijndael. The code (and some explanations) is below, but the results are, um, unusual, and I can't see what I am doing wrong. For testing, I have a program that generates a random 16-character string, encrypts it to a variable, and decrypts it. Running it in 500 iteration loops, it fails roughly 4% of the time. By "fails" I mean that the original string and the eventual decrypted one don't match. Anybody able to spot why? Ken -------------------------------------- function jagencdecr($text,$EorD,$encpass='') { // parameters: // - $text = string to be en/decrypted, // - $EorD = Encrypt or Decrypt // - $encpass = key phrase if (empty($text)) {return "";} $text = trim($text); $cypher = mcrypt_module_open('rijndael-256', '', 'ecb', ''); // "ecb" mode produces the above results. // "ofb" mode produces 100% errors

    	$size = mcrypt_enc_get_iv_size($cypher);
    	$phprand = rand(1000,9999);
	$iv = mcrypt_create_iv($size,$phprand); // produces the same results as below, platform independent

//$iv = mcrypt_create_iv($size,MCRYPT_RAND); // for Windows //$iv = mcrypt_create_iv($size,MCRYPT_DEV_RAND); // for 'NIX $ks = mcrypt_enc_get_key_size($cypher); /* Create key */ $key = substr(md5($encpass), 0, $ks); mcrypt_generic_init($cypher,$key,$iv); if ($EorD == "D") { $text_out = mdecrypt_generic($cypher,$text); } else { $text_out = mcrypt_generic($cypher,$text); } // endif ($EorD == "D") mcrypt_generic_deinit($cypher); mcrypt_module_close($cypher); return trim($text_out); } // endfunc jagencdecr Jaguar Ecnrypt/Decrypt