php encrypted string can not be decrypted

[bsetsu]

in PHP , I do this to encrypt, but the encrypted string can not be decrypted with FBEncryptor.
Am I doing something wrong?

rtrim(
base64_encode(
mcrypt_encrypt(
MCRYPT_RIJNDAEL_256,
$sSecretKey, $sValue,
MCRYPT_MODE_ECB,
mcrypt_create_iv(
mcrypt_get_iv_size(
MCRYPT_RIJNDAEL_256,
MCRYPT_MODE_ECB
),
MCRYPT_RAND)
)
), "\0"
);