The Wi-Fi represents wireless technology that includes the IEEE 802.11 family of standards (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11ac, etc.). Within 50m range, it operates in 2.4 GHz and 5GHz frequency bands,.
This technology was developed for wireless networking of computer devices and is commonly called WLAN (Wireless Local Area Network), where the communication is realized between wireless routers typically connected to the Internet and other wireless nodes within its range.
In correlation with performances of specific IEEE 802.11 standards, different data rates are enabled and their theoretical throughput is 11 Mbps (IEEE 802.11b), 54 Mbps (IEEE 802.11a and IEEE 802.11g), 100 Mbps (IEEE 802.11n) or 300 Mbps (IEEE 802.11ac). In the overcrowded 2.4 GHz frequency band, there are 14 channels dedicated for the Wi-Fi technology. In 5 GHz frequency band, RF channel distribution for Wi-Fi is correlated with national legislation and RF bands allocation plans. A new Wi-Fi HaLow (IEEE 802.11ah) standard is a technological successor of the current IEEE 802.11ac wireless protocol. It works at 900 MHz frequency band in the USA and significantly improves wireless coverage and energy efficiency as one of the most important features for smart homes, smart buildings and other IoT use cases.
Among other available choices, this technology is used in smart homes and smart buildings for use cases with high throughput audio/video streaming requests, centralized management applications, video monitoring and security systems, etc. Networking of multiple devices such as cameras, lights and switches, monitors, sensors and many others is enabled with this technology.
One of the major Wi-Fi benefits is its prevalence in almost all digital devices today and capability to provide high-capacity wireless links. From a security perspective, activation and implementation of supported encryption mechanisms provide acceptable protection, like Wi-Fi Protected Access (WPA) or WPA2. Wi-Fi technology enables generic IP compatibility, easy installation and operation procedures, possibility to add or remove the devices to or from a network with no particular management efforts and impacts to network functionality, efficient troubleshooting, etc. This technology can be implemented as a back-end network for offloading aggregated data from a central IoT hub to the cloud, which is a very important feature applicable to smart homes and smart buildings.
Some Wi-Fi drawbacks for smart home and smart building use cases are power consumption, higher infrastructure price, susceptibility to obstacles that limits the range, susceptibility to RF jamming—important for smart home or smart building security systems, available throughput is shared between connected devices, susceptibility to interference from the many devices that operate at the same frequency—including Wi-Fi and other wireless technologies devices like cordless phones, microwaves, etc.
The Wi-Fi Alliance enables the implementation of different security solutions across Wi-Fi networks through the Wi-Fi Protected Access (WPA) family of technologies. Simultaneously with Wi-Fi technology, deployable for personal and enterprise networks, security capabilities evolve too.
Today there are several available levels of security applicable to Wi-Fi networks implemented in WPA protocols, like WPA3 – Personal, WPA3 – Enterprise, WPA2, Open Wi-Fi and Wi-Fi enhanced open.
WPA3 security protocol
WPA3 is the latest generation of Wi-Fi security protocol. It is a successor of successful and widespread WPA2 protocol. WPA3 adds new security features to deliver more robust authentication, enable increased cryptographic strength for highly sensitive information exchange and support resiliency of mission critical networks. Once implemented, WPA3 protocol represents best security practices in Wi-Fi networks, while disabling obsolete security protocols and requiring usage of Protected Management Frames (PMF) at the same time. It includes additional features specifically to Personal or Enterprise networks and maintains interoperability with WPA2 protocol. WPA3 is currently an optional certification for Wi-Fi certified devices that will become mandatory in compliance with the market needs and growth.
WPA3-Personal protocol enabled better protections to individual users by providing more robust password-based authentication. This capability is enabled through Simultaneous Authentication of Equals (SAE), which replaces Pre-Shared Key (PSK) in WPA2-Personal protocol. Some of its advantages are natural password selection (allows easy to remember passwords), protection of data traffic even if a password is compromised after the data was transmitted and easy to use.
WPA3-Enterprise protocol is developed specifically for enterprises, governments and financial institutions, offering an optional mode that uses 192-bit minimum-strength security protocols and cryptographic tools for better protection of sensitive data. It is supported with authenticated encryption (256-bit Galois/Counter Mode Protocol – GCMP-256), key derivation and confirmation (384-bit Hashed Message Authentication Mode with Secure Hash Algorithm – HMAC-SHA384), key establishment and authentication (Elliptic Curve Diffie-Hellman – ECDH exchange and Elliptic Curve Digital Signature Algorithm – ECDSA, using a 384-bit elliptic curve) and robust management frame protection (256-bit Broadcast/Multicast Integrity Protocol with Galois Message Authentication Code – BIP-GMAC-256).
WPA2 security protocol
WPA2 protocol provides security and privacy to Wi-Fi networks since 2006. It is a well-known successor of an obsolete WPA security protocol. The major improvement in comparison with WPA is deployment of stronger AES encryption algorithms in WPA2 protocol.
During 2018, to meet security requirements in evolving networking environments, Wi-Fi Alliance augmented existing WPA2 protocol through configuration, authentication and encryption enhancement. By these enhancements, susceptibility to network misconfiguration is reduced and security of managed networks with centralized authentication services is supported.
Open Wi-Fi networks
In some use cases, open Wi-Fi networks are the only available option. It is very important to be aware of the risks that open networks present. To address these risks, Wi-Fi Alliance has developed a Wi-Fi Enhanced Open as a solution for users of open Wi-Fi networks. Compared to traditional open networks with no protection, Wi-Fi Enhanced Open certification provides unauthenticated data encryption to subscribers. It is based on Opportunistic Wireless Encryption (OWE) method defined in the Internet Engineering Task Force (IETF) RFC8110 specification and the Wi‑Fi Alliance Opportunistic Wireless Encryption Specification. Wi-Fi Enhanced Open enables data encryption that maintains the open networks ease of use and benefits network providers because of simple network maintenance and management.
The intensive evolution of security features in Wi-Fi technology makes it very deployable in the IoT domain and specifically to smart home and smart building use cases. Like other wireless technologies, it has some security challenges too. If we take into account the number of devices embedded with Wi-Fi chips, this becomes even more important. Some representative Wi-Fi security challenges are:
- Jamming susceptibility – a Wi-Fi signal can be easily jammed today. In smart homes or smart building, this attracts additional attention. If a home security system is based on Wi-Fi technology, intruders could effectively block the Wi-Fi signal and disable the alarm system.
- Because of the single point of failure (wireless router or Access Point), DoS attacks are potential risks for smart homes or smart building Wi-Fi networks. If the Access Point is out of service, there is no service availability and complete wireless network is malfunctioning.
- Eavesdropping is performed by simply getting within range of a target Wi-Fi network, then listening and capturing data. This information can be used for a number of unauthorized activities including attempting to break existing security settings and analyzing non-secured traffic. It is almost impossible to reliably prevent this category of attacks because of the nature of a wireless network. It is always important to set the complex parameters in security mechanisms.
- Evil Twins or Rogue Wi-Fi Hotspots are one of the most common ways for obtaining sensitive information from Wi-Fi networks. It represents a fake Wi-Fi access point that imitates the legitimate one. In this scenario, an SSID is state similar to original Access Point and any information disclosed while connected to Rogue Wi-Fi Hotspot could be misused.
- Packet Sniffers – by using a packet sniffer, it is possible to identify, intercept, and monitor web traffic over unsecured Wi-Fi networks and capture personal information such as login credentials to bank accounts and corporate email accounts.
- File-Sharing – if enabled on devices, it can be used for unauthorized access to a device connected to the Access Point or Wi-Fi hotspot and malware drop.
- Malware and Ransomware susceptibility of public Wi-Fi hotspots that could be a part of smart building. Without the protection of AV software and web filters, malware can be silently downloaded.
- A generic IP nature of Wi-Fi networks makes them a perfect surrounding for the testing of the new hackers’ tools and for improvements of the existing ones.
To maintain worldwide interoperability and secure communications between devices from different manufacturers, Wi-Fi alliance permanently improves the security solutions implemented in Wi-Fi technology, provides product certifications, forward and backward compatibility. This approach is very important for Wi-Fi support to different IoT use cases and particularly for smart homes and smart buildings evolution.
Marin Ivezic is a Cybersecurity & Privacy Partner in PwC Canada focused on risks of emerging technologies.