Eavesdropping occurs when a hacker is able to see the information contained within a packet. One way of preventing eavesdropping is to encrypt the information that is being sent.

  • Network layer encryption encodes the packet payload.
  • A router or firewall encrypts and decrypts packets.
  • A hacker with a packet sniffer can only see ciphertext in the packet payload.
  • The IP and transport layers remain in clear text format, so the packet can find its way to the destination address.