string blowfish_pass = "KD921231X3123211";
            BlowFish b = new BlowFish(blowfish_pass);
            string res = b.Encrypt_CBC(EncryptedString);


//php:
$blowfish_key = "KD921231X3123211":

$cs_output="27c7c634ead1d28bfe64821a28ef909311e1f655150f24eec27abff1376a7a8712e7962fdbb0150bfc0882078cb99e67";

$iv=pack("H*" , substr($cs_output,0,16));
$blowfish_key=pack("H*" , $blowfish_key); // key in this example is all zero
$x =pack("H*" , substr($cs_output,16));
$data = mcrypt_decrypt(MCRYPT_BLOWFISH, $blowfish_key, $x , MCRYPT_MODE_CBC, $iv);

echo $data;