A wireless access point (WAP) is a device that allows wireless communication devices to connect to a wireless network using Wi-Fi, Bluetooth, or related standards. The WAP usually connects to a wired network, and it can transmit data between wireless devices and wired devices on the network. Each access point can serve multiple users within a defined network area. As people move beyond the range of one access point, they are automatically handed over to the next one. A small WLAN requires a single access point. The number of access points in a network depends on the number of network users and the physical size of the network.
Answer option C is incorrect. A wireless network interface card (WNIC) is a network card that connects to a radio-based computer network, unlike a regular network interface controller (NIC) that connects to a wire- based network such as token ring or ethernet. A WNIC, just like a NIC, works on the Layer 1 and Layer 2 of the OSI Model. A WNIC is an essential component for wireless desktop computer. This card uses an antenna to communicate through microwaves. A WNIC in a desktop computer is usually connected using the PCI bus.
Answer option A is incorrect. ExpressCard, a new standard introduced by PCMCIA, is a thinner, faster, and lighter modular expansion for desktops and laptops. Users can add memory, wired or wireless communication cards, and security devices by inserting these modules into their computers. ExpressCard slots are designed to accommodate modules that use either Universal Serial Bus (USB) 2.0 or the PCI Express standard.
ExpressCard modules are available in two sizes, i.e., 34 mm wide (ExpressCard/34) and 54 mm wide (ExpressCard/54). Both modules are 75 mm long and 5 mm high. An ExpressCard/34 module can be inserted in either a 54 mm slot or a 34 mm slot, but an ExpressCard/54 requires a Universal (54 mm) slot. However, an extender can be used with ExpressCard/34 slot to connect the ExpressCard/54 module from outside of the computer. Both the modules are identical in performance. They take full advantage of the features of the PCI Express or USB 2.0 interfaces. The only difference between them is that the ExpressCard/54 form-factor, due to its larger surface area, allows for greater thermal dissipation than does an ExpressCard/34. As the performance does not vary with module size, module developers usually prefer to fit their applications into the smaller ExpressCard/34 form factor. But some applications, such as SmartCard readers, and CompactFlash readers, require the extra width of an ExpressCard/54 module.
Answer option D is incorrect. A wireless repeater is a networking device that works as a repeater between a wireless router and computers. It is used to connect a client to the network when the client is out of the service area of the access point. If the wireless repeater is configured properly, it extends the range of the wireless LAN network.

Session hijacking refers to the exploitation of a valid computer session to gain unauthorized access to information or services in a computer system. In particular, it is used to refer to the theft of a magic cookie used to authenticate a user to a remote server. It has particular relevance to Web developers, as the HTTP cookies used to maintain a session on many Web sites can be easily stolen by an attacker using an intermediary computer or with access to the saved cookies on the victim's computer (see HTTP cookie theft).
TCP session hijacking is when a hacker takes over a TCP session between two machines. Since most authentication only occurs at the start of a TCP session, this allows the hacker to gain access to a machine.
Answer option A is incorrect. Spoofing is a technique that makes a transmission appear to have come from an authentic source by forging the IP address, email address, caller ID, etc. In IP spoofing, a hacker modifies packet headers by using someone else's IP address to hide his identity. However, spoofing cannot be used while surfing the Internet, chatting on-line, etc. because forging the source IP address causes the responses to be misdirected.
Answer option B is incorrect. Smurf is an attack that generates significant computer network traffic on a victim network. This is a type of denial-of-service attack that floods a target system via spoofed broadcast ping messages. In such attacks, a perpetrator sends a large amount of ICMP echo request (ping) traffic to IP broadcast addresses, all of which have a spoofed source IP address of the intended victim. If the routing device delivering traffic to those broadcast addresses delivers the IP broadcast to all hosts, most hosts on that IP network will take the ICMP echo request and reply to it with an echo reply, which multiplies the traffic by the number of hosts responding.
Answer option D is incorrect. Phishing is a type of scam that entices a user to disclose personal information such as social security number, bank account details, or credit card number. An example of phishing attack is a fraudulent e-mail that appears to come from a user's bank asking to change his online banking password.
When the user clicks the link available on the e-mail, it directs him to a phishing site which replicates the original bank site. The phishing site lures the user to provide his personal information.

Asymmetric
Explanation:
Asymmetric encryption is a type of encryption that uses two keys, i.e., a public key and a private key pair for
data encryption. The public key is available to everyone, while the private or secret key is available only to the
recipient of the message. For example, when a user sends a message or data to another user, the sender
uses the public key to encrypt the data. The receiver uses his private key to decrypt the data.