Why do most of the airports have OTP-based limited WiFi?

OTPs are like tokens that help each user connect to a network in a secure manner. A wireless network can be used in a way that a single password is not shared with multiple users. Each individual has his own password/token to access the network.

Usually token based authentication is performed with the help of a captive portal. The user is redirected to a web page to authenticate.

Web based authentication can take place over https so that the data transmission is encrypted.

This setup is different from the one that we use in our homes, for example, where a single password is shared with the members of the family. Thus it overcomes the limitation of the WPA2 encryption scheme making it secure. [1]

As for the limited part there could be multiple reasons. But it is important to remember here that airports are generally not responsible for providing internet/wifi. Most likely they outsource it to some service provider who then works with the management team and at some point in time they conclude (rightly!) that to provide effective service to as many users as possible some limitations must be placed on the usage of the network. These limitations can be

Time based. You can only use it for 30 minutes/1 hour/1 day

Data based. You can only use 1Gb of data in a day.

Speed based. Each user can have a maximum of 1MB/sec of speed

Or any number of combinations.

If we consider the alternative, that is wifi without any limitations, a few people will hog all the bandwidth by playing games or streaming movies/watching youtube etc leaving other guests with little or no data.

Even in its limited form access to the internet is helpful for foreign tourists for example who don’t have a local SIM card and would have to pay exorbitant international roaming charges otherwise.

[1]In sensitive communication environments neither wpa 2 psk nor captive portals are the best solution. Use wpa 2 enterprise instead.

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Notes by Akshat Jiwan Sharma

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