AsianScientist (Jan. 21, 2015) – With the exception of a few die-hard resisters, you can reasonably expect that most people would have some sort of social media presence, whether it be on Facebook, Twitter or Instagram. A testament to our inherent sociality as a species, the desire for convenient communication over the Internet has nevertheless come at a price: the erosion of personal privacy.
“Often people’s gut instinct is that it is impossible to achieve privacy, so there is no point in trying,” Professor Shafi Goldwasser, winner of the 2012 Turing Award, told Asian Scientist Magazine at the Global Young Scientists Summit (GYSS@one-north 2015). “That is not a misunderstanding of what’s currently going on, but it is a misunderstanding of what is possible.”
That misunderstanding is borne out in the reactions to the various information security scandals of late. After the initial outrage following Edward Snowden’s revelation that the United States government has the ability to spy on its citizens, the general public has continued to use the Internet with impunity, seemingly resigned to the trade-offs involved. This need not be the case, Goldwasser stressed.
“There are many things we can do with the mathematics—it’s just that they appear somewhat paradoxical if you think about them in the physical world,” she said. “The idea that you can compute on the data without actually looking at it, or that you can actually verify something without looking at all the steps; it’s a bit mind boggling.”
Anticipating the revolution
Encryption didn’t start out this complicated. Harking back to ancient Rome, the first cryptographic systems required people to physically meet and exchange a key which would allow them to encrypt and decrypt secret messages. But the advent of the Internet age demanded a new approach.
“In 1976, it dawned upon Diffie and Hellman that the availability of digital computers and networks was nothing short of a revolution, even though it was only realized many years later. They reasoned that if you wanted to use this underlying technology to do commerce, then you had to move away from the idea of two people meeting and setting up the code. What was developed in 1977 was a public key system known as RSA (short for Rivest-Shamir-Adleman cryptosystem), and it’s still the backbone of what we do today,” Goldwasser explained.
However, even though the need for encryption was recognized, people were still not entirely sure what they expected a good encryption system to do. Even in the simple scenario of transmitting two related messages, simply hiding the message is not enough to prevent an attacker from breaking the code.
“In a more sophisticated protocol, say a poker game where you encrypt all the cards, then even though you cannot exactly find out which card is encrypted it’s possible to find out some information of the card which is encrypted— like if its high card or low card—and that would lead to strategies of cheating. So the question to articulate was what you wanted truly secure encryption to achieve. Mathematically speaking, that’s captured by saying that no attack will be unable to find any partial information, or equivalently you cannot distinguish in any way the encryptions of two different messages,” Goldwasser said.
“Then the question becomes: how to achieve that. Our contribution was to show that you could not achieve it without randomization; and show randomized techniques where every message has exponentially many possible encryptions. For these techniques, we could prove that now all partial information will be hidden, but still the legal recipient on the other side can decipher the message uniquely.”
While playing poker or passing secret messages may sound trivial, randomized or probabilistic encryption in fact finds countless useful applications. Modern systems, such as fully homomorphic encryption where you can encrypt data in such a way that you can still extract some information from it without recovering everything, are particularly promising in Goldwasser’s eyes.
“It would be highly beneficial, for instance, to see if there was a correlation between DNA and certain diseases. However, people may be unwilling to give their DNA if their genetic information is used against them. Our idea is to encrypt the DNA such that can you recover what you are looking for, such as a particular gene, without revealing the entire sequence.”
For her landmark contributions to encryption and many other subfields of computer science, Goldwasser has been recognized with numerous awards, including the RSA Award in Mathematics for Outstanding Mathematical Contributions to Cryptography (1998), two Gödel prizes (1993 and 2001) and the IEEE Emanuel R. Piore Award (2011). More recently, she became the third woman to receive the prestigious Turing Award (2012), widely considered the Nobel Prize in the field of computer science.
An immensely rewarding career
Acknowledging that getting more women to participate in STEM fields is a global challenge, Goldwasser encourages female scientists not to let having children take them permanently away from research.
“The main thing I can say is: it’s worth it. We live in a world with a lot of fascinating developments, and science and technology is where it’s at; why would you not want to be part of it? It’s fascinating, intellectually stimulating and extremely rewarding to do something that you’re curious about,” she mused.
It might come as some surprise then, that Goldwasser harbored slightly different visions of her future career as a child—she had wanted to become a writer. Nevertheless, good writing skills have contributed to her present career in the form of well-crafted research papers.
“When you publish a technical paper, there are many ways to write it. You could write it very dryly, just to report your findings. Another way is to explain why you’re studying these problems, drawing connections to other sciences or even general philosophical questions like what is privacy, what does it mean to know,” she said.
“I think that papers written in this fashion become the ones that you would want to read 20 years later, even after the science has progressed. That’s because these philosophical concerns don’t change.”
Asian Scientist Magazine is a media partner of the Global Young Scientists Summit (GYSS@one-north 2015), taking place from 18-23 January, 2015 at Nanyang Technological University, Singapore. GYSS@one-north 2015 is organized by the National Research Foundation of Singapore in collaboration with its partners.
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Copyright: Asian Scientist Magazine.
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