Online DES-OFB Data Encryption

DES-OFB

OFB (short for output feedback) is an AES block cipher mode similar to the CFB mode. In OFB blocks are independent of one another, both encryption and decryption of blocks can be done in parallel once the pad vectors have been generated. The lack of interdependency also means that the OFB mode is tolerant to the loss in blocks. A significant drawback of the OFB is that repeatedly encrypting the initialization vector may produce the same state that has occurred before. This is an unlikely situation, but in such a case, the plaintext will start to be encrypted by the same data as it was previously.