Strengthening WEP protocol for wireless networks using block chaining algorithm with variable encrypting function mechanism

The encryption scheme in the wired equivalent privacy (WEP) protocol for networks based on the 802.11 standards has been proven to have several weaknesses. We propose a mechanism called the variable encrypting function (VEF) to enhance the protection offered by the WEP. The VEF mechanism is based on increasing the ´diffusion´ characteristic, at the application layer, by making the ciphertext character dependent on the current plaintext character and the previous plaintext character. A message dependent matrix is generated which is used to perform the transposition operation on the obtained ciphertext.