The Cipher Feedback (CFB) mode processes small increments of plain text into cipher text, instead of processing an entire block at a time. This mode uses a shift register that is one block in length and is divided into sections. For example, if the block size is 8 bytes, with one byte processed at a time, the shift register is divided into eight sections. If a bit in the cipher text is mangled, one plain text bit is mangled and the shift register is corrupted. This results in the next several plain text increments being mangled until the bad bit is shifted out of the shift register. The default feedback size can vary by algorithm, but is typically either 8 bits or the number of bits of the block size. You can alter the number of feedback bits by using the SymmetricAlgorithm.FeedbackSize property. Algorithms that support CFB use this property to set the feedback.