SymmetricAlgorithm: CipherMode


A defined set of cipher modes the algorithms can use.

 Public Enum CipherMode


CBC = 1
The Cipher Block Chaining (CBC) uses a feedback mechanism by Exclusive ORing the previously encrypted block of data with the current block being processed. This is to prevent two identical blocks from encrypting into the same to encrypted blocks of data, making it more difficult to break the encryption. An Initialization Vector array is also used by Exclusive ORing the vector with the current block before encryption.
ECB = 2
The Electronic Codebook (ECB) processes blocks individually and does not alter identical blocks of data. If two or more blocks of data are the same then their encrypted blocks will also be the same. A message with several identical blocks could become easier to decrypt.
OFB = 3
The Output Feedback (OFB) method processes small increments of blocks into ciphered text instead of the entire block at one time. This works similar to the Cipher Feedback method, except if a ciphered bit is corrupted, then all plain text data following the bit will be corrupted.
CFB = 4
The Cipher Feedback (CFB) method processes small increments of plain text into ciphered text instead of the entire block at one time. The method uses a shift register that is one block in length. If one bit of ciphered data is corrupted, then the corrisponding plain text bit is also corrupted until the corrupted bit is finally shifted out of the register.
CTS = 5
The Cipher Text Stealing (CTS) mode handles any length of plain text and produces cipher text whose length matches the plain text length. This mode behaves like the CBC mode for all but the last two blocks of the plain text.


See Also

Project VBCorLib Overview Class SymmetricAlgorithm Overview SymmetricAlgorithm Properties SymmetricAlgorithm Methods BlockSize (let) Clear