A replay attack (also known as playback attack) is a form of network attack in which a valid data transmission is maliciously or fraudulently repeated or delayed. This is carried out either by the originator or by an adversary who intercepts the data and retransmits it, possibly as part of a masquerade attack by IP packet substitution.
Suppose Alice wants to prove her identity to Bob. Bob requests her password as proof of identity, which Alice dutifully provides (possibly after some transformation like a hash function); meanwhile, Darth is eavesdropping on the conversation and keeps the password (or the hash). After the interchange is over, Darth (posing as Alice) connects to Bob; when asked for a proof of identity, Darth sends Alice's password (or hash) read from the last session, which Bob accepts thus
granting access to Darth
Wireless Technology
wireless networks and technologies allow devices to send data to each other and to the web (TCP/IP Networks) without cables. There are a number of different wireless technologies out there that can be implemented in hardware products for the Internet of Things (IoT) and Machine to Machine (M2M) communication.
These are 5 types of Wireless Technology For The IoT;
IEEE 802.15.4: [Zigbee]
A wireless technology currently gaining traction in the LPWAN group, ZigBee is an open global standard and is designed specifically to be used in M2M networks. The technology is inexpensive to run and doesn’t require a lot of power, making it an ideal solution for many industrial applications. The technology has a low latency, and a low duty cycle, allowing products to maximize battery life.
IEEE 802.11: [WiFi]
WiFi uses radio waves (RF) to allow two devices to communicate with one another. The technology is most commonly used to connect Internet routers to devices like computers, tablets and phones; however, it can be used to connect together any two hardware components. WiFi is a local wireless network that runs of the 802.11 standards set forth by the Institute of Electrical and Electronics Engineers (IEEE).
IEEE 802.15.1: [Bluetooth and BLE]
Bluetooth and Bluetooth Low Energy (BLE) are wireless technologies used to transfer data over short distances. The technology is frequently used in small consider devices that connect to users phones and tablets. For instance, the technology is used in many speaker systems. Bluetooth Low Energy uses less power than standard Bluetooth and is used in hardware such as fitness trackers, smart watches and other connected devices in order to wirelessly transmit data without heavily compromising the battery power in a user’s phone.
IEEE 802.16: [WiMax]
WiMax stands for Worldwide Interoperability for Microwave Access. This wireless technology allows data to be transferred at a rate of 30-40 megabits per second. The term refers specifically to interoperable implementations of the IEEE 802.16 wireless family. The technology was once used by several mobile carriers, notably Sprint, to deliver wireless data to its customers. Sprint, along with many of the other carriers who used the technology, has since switched over to using faster LTE 4G networks for data..
