Information on the OFB mode---------------------------The OFB uses an initialization vector (z_0 = IV). This vector is encryptedusing an encryption algorithm in ECB mode. The encrypted buffer is then XORed with the plaintext to get the ciphertext.	z_i = e_k(z_i - 1)	y_i = x_i ^ z_i	i >= 1	z_i: This is the stream which is encrypted using the encryption	     algorithm.	x_i: Plaintext. 	y_i: Ciphertext	e_k: Encryption-Algorithm.The OFB mode is self-inverse, hence the same function is used for decryption.Links:	http://www.rsasecurity.com/rsalabs/faq/2-1-4-5.html	http://www.iks-jena.de/mitarb/lutz/security/cryptfaq/q83.html