Nowadays, lots of data go through wireless networks. A lot of people don’t pay attention to the fact that third parties might be able to join these networks to snoop around and read this data when not properly encrypted. Decryption tools are getting more and more sophisticated so it is very important to only use wireless networks that have a sufficient grade of protection.
Otherwise, you run into the risk of someone obtaining some of your data you don’t want to share. Attackers need networks with low security and unaware, impatient web users to pull off their attacks. Unfortunately, a lot of public networks and plenty of us as persons (myself included) are part of these categories. I think we should be a bit more aware of the risks of networks and the risk of being uncareful ourselves.
Networks: LAN and WIFI
First, let’s get a grasp of networks in general. To get on a network (internet, internal company network, etc.) you need access. When you are at the office or at home you do this by accessing a Local Area Network (LAN). A LAN is protected by physical security mechanisms (for example controlled access to a building and physical cables from a network socket to a computer). To get onto the network you have to be physically at a workplace with a cable connected to the network. It’s easier to identify people snooping around because they have to be physically present to have access to the network. Strangers will immediately be identified.
Nowadays it’s more and more common to use wireless networks: WiFi. It’s not an abbreviation. The name WiFi was created by a marketing firm because the wireless industry was looking for a user-friendly name to refer to some not-so user-friendly name known as IEEE 802.11. And the name stuck. WiFi networks are getting more and more popular compared to the classic LAN network. In some offices you even see LAN disappearing and getting replaced by WiFi. The reason for this is that the quality/performance of WiFi has been improving dramatically and this process is still ongoing. Still, a LAN network is more stable and quicker.
To run a WiFi network, you need a wireless router. This is a small electronic device, supplied by an internet service provider (ISP), to connect to the internet. It connects to your home broadband line and sends data from the internet cable to your WiFi-connected devices. Wireless routers are nowadays the industry-standard because wired routers have long been outdated, and are nowadays only used by those who want to connect to the internet via a physical cable.
The WiFi router works by converting data into radio signals that are then picked up by devices with a WiFi reception such as desktop stations with a WiFi card, laptops, smartphones, game consoles, and Internet of Things devices. You can also use your router to connect WiFi-capable devices to stream and download digital TV. Examples are Apple TV, Google’s Chromecast, and all smart TVs.
WiFi Router Security: WEP
WiFi standard was released in 1997 and it included WEP as extra security. WEP stands for Wired Equivalent Privacy and supposedly offered the same expectations of confidentiality that users today expect from wired networks. This sounds very nice but it was a bit of a hassle because WEP required a 10-digit or a 26-digit hexadecimal preshared key that looked like this: 0A2EE221A. If you entered a character that wasn’t in the hexadecimal (0-F) range, you got an error and nothing worked. Because it was a hassle to use, most people turned WEP off, if it was even enabled in the first place. Later revisions of WEP offered the ability to create human-readable passwords in a way that was consistent between your computer and the router (10 or 26 characters). With the introduction of this, WEP started to be used more frequently.
Although WEP was used more frequently, the encryption was still not exactly state of the art. This meant that it was still relatively easy for someone else to join the same network as you did and to snoop around. Because everything was encrypted and decrypted with the same PST (short for Personal Storage Table), it was very easy for someone to intercept and read all your traffic, sent out to the internet. Nowadays, WEP still has serious and unfixable cryptographic weaknesses that can be exploited to crack any WEP network in minutes. The tools to do so are far more sophisticated than in the past and a surprising number of (public) WiFi networks still use WEP. There are apps like Wigle Wifi that allow anyone to identify WEP networks, simply by walking or driving by a network.
WiFi Router Security: WPA1/TKIP
Because of the serious weaknesses of WEP, an organization named WiFi Alliance decided to introduce a new security protocol. They called it WPA. WPA stands for WiFi Protected Access and was developed by the WiFi Alliance to secure wireless computer networks. WPA was introduced in 2003 and the first version (WPA1) was an intermediate solution in anticipation of the availability of the more complex WPA2. Still, the security of WPA1 was an improvement compared to WEP. WPA1 security protocol implements the TKIP (Temporal Key Integrity Protocol). TKIP is a security protocol used in the IEEE 802.11 wireless network standard.
This IEEE 802.11 standard is used in most home and office networks to allow laptops, printers, smartphones, and other devices to communicate with each other and access the internet without connecting with physical wires. The IEEE standards are created by the Institute of Electrical and Electronics Engineers and the base version of IEEE was released in 1997.
Let’s switch back to the security protocol used in IEEE 802.11. This TKIP was designed by the IEEE task group in collaboration with the WiFi Alliance. TKIP (WPA1) ensures that every data package you send over the network has a unique encryption key. Key mixing increases the complexity of decoding the keys by giving an attacker substantially less data that has been encrypted using any one key (which was the case with WEP). So compared to WEP, WPA1/TKIP was a big improvement. As of now, TKIP itself is not considered safe anymore. Yes: technology caught up and it’s not too hard to hack TKIP/WPA1 nowadays. It was therefore depreciated in 2012 in the revision of the 802.11 standards.
WiFi Router Security: WPA2/AES
In 2004, IEEE released a new security protocol (remember that WPA1 was just an intermediate solution) in collaboration with the WiFi Alliance: IEEE 802.11i-2004 (or short 802.11i). WiFi Alliance refers to their approval of the full 802.11i as WPA2. The main difference with WPA1 is that WPA2 uses the Advanced Encryption Standard (AES) instead of TKIP. AES is the first and only publicly accessible cipher approved by the US National Security Agency (NSA) for protecting top-secret information. AES was first called Rijndael after its two developers, Belgium cryptographers Vincent Rijmen and Joan Daemen. AES is a completely different type of encryption to protect your WiFi network than TKIP. TKIP is a rather old encryption protocol that has a lot of similarities to the super unsafe WEP encryption, only created for WiFi networks. AES is far more than that. It is a serious worldwide encryption standard that has even been adopted by the US government as stated before. The only vulnerability it has is a brute-force attack which can be prevented by a strong password. WPA2 has been the most used standard for both business (WEP/WPA1 was never used because of limited security) and home.
In 2017 a serious vulnerability was found by researcher Mathy Vanhoef of the Katholieke Universiteit Leuven in Belgium. His proof-of-concept was called KRACK which is short for Key Reinstallation Attacks. This allows attackers to reuse a one-time key that is provided when a client device attempts to join a WiFi network. Doing so enables the attacker to decrypt information being exchanged between the access point and the client device. This way an attacker can intercept passwords, e-mails, and other data presumed to be encrypted and in some cases to integrate ransomware or other malware into a website a client is visiting. This has nothing to do with the AES encryption which has not been cracked as of today though. Possible attacks have indeed been described on AES but these are all not practical in the real world. The quickest attack on AES has been a key-recovery attack that improved on brute-forcing AES by a factor of four. It would still take a few billion years to eventually crack the encryption with this tool so at this moment it is not useful in practice. KRACK concerns other parts of the WPA2 protocol that are not completely secure.
Despite updates to WPA2 to mitigate against KRACK vulnerabilities, WPA2 can still be cracked. If you search the internet you can find all kinds of manuals that teach you how to crack WPA2. In addition, there are other vulnerabilities in WPA2 as well. One of the biggest vulnerabilities is that the attacker does not have to stay connected to the network to guess the password. The captured traffic can be used offline in a word list or a dictionary-based attack to guess the password. If the password is weak it can be broken pretty easily. These security challenges resulted in having a new king in town since 2018.
WPA3
Yes, WPA3 is the new king. Not a very original name but it makes sense to name the new protocol WPA3 to show that this is the successor of WPA2. WPA3 was introduced in 2018 and has been required for new devices since July 1, 2020. WPA3 is a huge security upgrade compared to WPA2:
- WPA3 fixes the KRACK vulnerability and mitigates other problems (for instance word list or dictionary-based attacks) as well by using a different handshake mechanism for authenticating to a WiFi network. This is called Simultaneous Authentication of Equals (also known as Dragonfly Key Exchange). With this standard, it is more difficult to guess WiFi passwords offline by word lists or dictionary attacks.
- WPA3 offers forward secrecy. This has the advantage that previously exchanged information is better protected. Wireless networks use radio signals to transmit information (data packets) between a client device (phone, computer, etc.) and the WiFi access point (router). These radio signals are broadcasted without protection which means that anyone in the vicinity can intercept the information. WPA2 and WPA3 are protected with a password so the signals are encrypted. Because of this, the interceptor can’t understand the data. But an attacker can record all the data that is intercepted. This means that if the attacker can guess the password in the future (and this is possible with a word list or dictionary attack on WPA2), the key can decrypt the data traffic recorded in the past on that specific wireless network. WPA3 provides forward secrecy. This protocol, Transfer Layer Security (TLS) is designed in a way that even with the network password, it is impossible to eavesdrop on traffic between the access point and a different client device. Even if a long-term encryption key is compromised.
- Opportunistic Wireless Encryption (OWE) is a brand new feature in WPA3 as well. It replaces the 802.11 “open” authentication that is widely used in hotspots and public networks. The decryption key for the communication is different for every client that connects to the access point. This means that no other devices on the network can decrypt your communication, even if they listen in on it (called “sniffing”). This extra safety is called Individualized Data Protection. Attackers can sniff and record your traffic but they can’t decrypt it. OWE doesn’t only protect networks that require a password to connect. It also protects open (unsecured) networks that don’t have a password (for instance public WiFi networks). OWE encrypts these networks without authentication. Be careful when buying a WPA3 router though (!). WPA3 supports but does not mandate OWE. So it is possible that a manufacturer stamps the WPA3 label on a router without implementing unauthenticated encryption. The OWE feature is called “WiFi Certified Enhanced Open” so you should look for this label in addition to the WPA3 label to make sure that the device you are buying supports OWE. OWE does not protect against ”rogue” access points:
- Honeypot access points in combination with a man-in-the-middle attack: illegal WiFi access points (APs) that can appear as authorized and secure hotspots. However, they aren’t and they are intended to steal your bank and credit card details, passwords and other personal information. Honeypots trick wireless users into connecting their laptops or mobile phones to these fake hotspots by pretending they are legit. Once you connect, the attacker can launch a man-in-the-middle attack which you are automatically being directed to a certain kind of website you might consider as legit and that asks for specific details (like credit cards, passwords, etc.) in order to steal them. If you “dodge” the fake website and don’t provide any sensitive details, you are still not safe. Anyone who logs into the attacker’s network is monitored by the attacker. If a user logs into something sensitive (like a bank account) from a legit website, the attacker can see all the login details and save them for later use.
- Evil twin is more of an advanced version of a honeypot in my opinion. In this case, the attacker looks out for a location with free, popular WiFi. The attacker then identifies the Service Set Identifier (SSID): the name of the WiFi network. After that, the attacker uses a tool like WiFi Pineapple to set up a new account with exactly the same SSID. To make it more tempting, the attacker can move close to a victim in order to make the attacker’s connection signal stronger than the valid one. Any new person will only see the evil twin and they will choose that network. Another tactic for the attacker is to start with a Distributed Denial of Service (DDoS) attack on the valid server that will take the server (and its free network) offline. This creates massive logins on the evil twin network because there is then only one network left: the one of the evil twin. When you want to log into a public WiFi network, you are most of the time guided to a generic login page of the provider. The attacker will make an exact duplicate of this login page in order to try to trick the victim into offering up authentication details. Like the honeypot, you are still not safe if you dodge the starting page: the attacker can monitor everything and can see any information that you provide on any (legit) website while being on the attacker’s network.
- WPA3 replaces the less secure WiFi Protected Setup (WPS) with the WiFi Device Provisioning Protocol (DDP). A lot of home devices can be categorized as the Internet of Things (IoT). They don’t have an interface themselves for password entry and rely on smartphones for their WiFi Setup. DDP allows these devices to be authenticated to the WiFi network without a password, using either a QR code or NFC (Near-field communication). NFC enables short-range communication between compatible devices. It requires one transmitting device and another device to receive the signal and works the same as Bluetooth and WiFi: signals are transmitted via radio waves. The main difference between NFC and Bluetooth/WiFi is that passive devices don’t require their own power supply with NFC. With Bluetooth/WiFi, they do. NFC is for instance applied in wireless transactions like Apple Pay or Android Pay. With WPS you communicate the password by phone to the IoT device, which is used to authenticate to the WiFi network. DDP performs mutual authentication without a password which is safer. Like OWE, WPA3 supports but does not mandate DDP but is part of the WiFi Alliance “WiFi Certified Easy Connect” program. So also, in this case, look out for this label when you buy a WPA3 device.
- WPA3 uses longer encryption keys than WPA2 which means more security. For consumer applications, longer key sizes are optional. Some manufacturers will use longer key sizes because they are now supported in the protocol but others might not: it’s up to a consumer to choose a router/access point that does or does not. WPA3 also refers to enterprise authentication. This means that it uses not only a password but also a username if you want to connect to a wireless network. This is different compared to a pre-shared key (you only need a password to log in then: the login name is not required) that is typical for home networks.
Final thoughts
My advice is never to join a public network without a Virtual Private Network (VPN) connection. You can’t always determine the protection grade of a public network and worst case it’s WEP, WPA, or even a Honeypot/Evil Twin. I would choose to better be safe than sorry.
Check your router at home as well and if WPA2/WPA3 is not an option, replace the old router with one that has at least WPA2 security protocols (I would personally even consider moving from WPA2 to WPA3). It’s worth the money to jump to WPA3 because of the huge security upgrades of WPA3 compared to its predecessors. Because it’s hard to keep up with all the technological advancements these days (this also means the advancements that attackers make), what appears to be a minor problem can be a huge issue within a short period of time.
I don’t think many offices use a legacy router (read: ancient routers that could belong to your grandfather) so a router with WEP or WPA1 security protocols is very uncommon. You never know though so it’s fun to just check it out with your IT department just to be sure. As a business, I would always go for WPA3 because of the reasons previously mentioned. Especially these days, I would not be cheap about cybersecurity.
Feel free to contact me if you have any questions or if you have any additional advice/tips about this subject. if you want to keep in the loop if I upload a new post, don’t forget to subscribe to receive a notification by e-mail.
