Looking for more secure network access? Math to the rescue. University cafeteria uses complex calculus question as wifi password

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The most difficult Wi-Fi password ever! Chinese university makes students answer calculus question to unlock internet access
Students at the elite Nanjing University of Aeronautics and Astronautics are asked to solve a complex calculus question before they could access the protected network. 'Wi-Fi password is the first eight digits of the math problem below,' the sign indicated in Chinese.

Ji jun, deputy director of the university's food administration department, told Beijing News that it is a basic question in further maths. 'If a student can't solve it, he/she should really study harder,' she said. 'Don't use the Internet!' The school decided to come up with the question to let pupils have fun with mathematics and to remind first-year students to study hard, she added.

One student told reporters that if a a person has practiced enough, you should be able to solve the equation in 30 seconds. Some posted images of their answers online, completed with steps showing their work. The answer - which is a familiar number to many - is actually 31415926, or pi.

Thai restaurant in San Antonio, Texas, created a brilliant way to make sure that nobody camped out at their restaurant for free Wi-Fi, but still gave its customers the ability to log on to their network. If they're a super math nerd, that is.

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Photo courtesy Weibo / Nanhang Dining Hall