Wireless technology is becoming increasingly popular in process industry. We see it applied for handhelds, gas detectors, cameras, tablets / notebooks, and wireless sensors. The first group of applications makes use of what is called the WIFI network, 802.11 technology, the same technology as used in office and home networks.
Wireless sensors are connected to a different and more reliable type of wireless network, 802.15.4 technology such as used by ISA100.11a and WirelessHart.
Wireless Sensor Network (WSN) security differs from WIFI because:
- WSN networks need to deliver real-time deterministic performance;
- WSN devices such as transmitters and valve positioners are constraint in computational capabilities (memory, CPU, bandwidth) and frequently battery powered;
- WSN devices are easily accessible because they are located in the field at fixed positions and often not tamper resistant.
A WSN communication channel is open in the air, so attacking it is not a difficult task. Some of the attack scenarios against WSN are:
- Eavesdropping, data injection, and traffic analysis attacks;
- Denial of Service attacks;
- Protocol specific attacks, such as attacks on time synchronization;
- Impersonation attacks like a sybil attack, client mis-association, or roque access points.