By Siena Fagan
If you have ever digitised anything – bank details, your face ID or a text conversation with your mum – you have an encryption key.
This number with thousands of digits acts like a cipher for every “message” that you send over the internet, including online shopping and browsing social media. It is created by multiplying two large prime numbers to produce a third number.
To decrypt your cipher, a hacker must factorise the third number: that is, find those two original prime numbers. This would take a classical computer the same amount of time as the universe’s existence.
Professor Nalini Joshi has been named the NSW Scientist of the Year.Credit: Sam Mooy
But quantum computers can factorise these massive encryption keys increasingly quickly. And, as these quantum computers become faster, the security of every digital system could collapse.
University of Sydney Professor Nalini Joshi AO is developing the mathematics to make encryptions stronger so your secrets cannot be unlocked.
Joshi is the first mathematician to receive the NSW Scientist of the Year award.
The chair of applied mathematics at the University of Sydney specialises in quantum cryptography, an emerging field protecting private information from being stolen by future hackers.
“We have to find ways to protect our data from those algorithms that will run on quantum computers. And the way we’re going to do that is to create new tools that come from mathematical ideas that haven’t been used yet,” she says.
Growing up in Burma, Joshi fell in love with science as a child.
“I wanted to try and understand the universe,” she says, “I would look at the shadows on the hills far away, and think, what are those shadows on the hills from?”
She began noticing mathematical patterns when playing games, and then in school science experiments, discovering that she could find solutions using numbers.
Joshi describes maths as a magical power with an importance that cannot be overstated.
“It’s like the air we breathe. It’s essential to our lives, but people don’t pay attention to it because it’s invisible.”
Joshi immigrated to Australia with her family aged 12, following a period of political unrest in Burma. Here, she discovered science fiction, which drove her interest in astronomy and astrophysics.
She attended Fort Street High School and earned a bachelor of science with honours from the University of Sydney before completing a PhD at Princeton University.
Joshi is Sydney University’s first female chair of applied mathematics. She has previously won a Eureka Prize for outstanding mentorship of young researchers and is an officer of the Order of Australia.
The NSW Scientist of the Year is named at the recommendation of the Office of the Chief Scientist and Engineer, which is accepted by the premier, and awarded by the governor.
Joshi will receive the award at a ceremony at NSW Government House on Wednesday evening.
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