Few days ago I watched a video on Youtube about creating a portable hacking device using Raspberry Pi running Kali Linux. You can watch the video here.
While I admire creativity of making a miniature hacking device, given a thumb up to the video, I highly doubt about its efficiency at least in the use case of cracking WiFis.
Firstly, a quality WiFi dongle needed which usually has an antenna attach to it to receive strong signals as apparently we don’t want to crack own network. And the WiFi dongle must be compatible with the cracking tools (i.e., Aircrack). This to some extend jeopardizes the portability concept. Same reason for power bank.
Secondly, carrying such a device outdoor gets people attention in the first glance. For instance, imagine taking the device to Starbucks, sitting there and start cracking WiFis around. Doesn’t it look like a treat to people? I do believe some, less educated, people might even call 911 because they mistakenly would think some terrorist activities going on.
Thirdly, one approach of cracking a WiFi network is brute-force (dictionary) attack that better to have a faster computer to be able to crack the password faster. With an i7 computer cracking a password by brute-force might takes up to weeks depending on how complex the password is, guess how long it takes for a Pi processor.
Fourthly, if you ever need to connect to the Internet using WiFi while you are hacking, well you need to have another dongle to do so. Or you need to find an Ethernet plug to connect to the Internet. Or a bluetooth dongle or USB cable to use phone tethering.
In conclusion, I don’t think it is much feasible to be able to hack a WiFi network in the scenario I described when probably some people staring at you and in their eyes you are playing with a weird (Raspberry Pi) device.
Apparently, for a serious crack, more tangible solution would be using a laptop, 2-in-1 laptop/tablet or a rooted Android phone/tablet.
My justifications are so simple. All the devices (laptop, phone, tablet, 2-in1) are easier to setup and perhaps more powerful. Besides, none of the devices look weird to people and doesn’t get any attention. Finally, you don’t need to be worry about the accessing to the Internet. As far as it comes to laptop and 2-in-1 both have USB ports, built-in bluetooth, and probably sim card slots. And in case of phone obviously mobile data can do the job.