Game Theory for Privacy
Privacy can mean different things to different people—for one it can be the safeguarding of their information, for another it’s secrecy, and yet for others there can be a different definition. In society, privacy serves several important functions such as preventing powerful parties from having too much control over people and allowing people to safely explore ideas. There are significant risks to privacy today because of modern technology. Game theory provides an interesting framework through which we can analyze privacy risks.
One common scenario concerning privacy is when a person gives their personal information to a company. Some benefits include saving time and money, and risks include the company exploiting the data and a data breach. Since games involve rational players who think about the benefits of their actions in addition to possible responses from others, we can use them to examine the behaviors of both the person and the company. In their article, Rajbhandari and Snekkenes look at a user subscribing to some service offered by an online bookstore. They use a two player game, exactly like the ones discussed in class. This is the payoff matrix for the situation:
(Rajbhandari and Snekkenes 48)
This game does not have a pure strategy Nash equilibrium because no pairs of strategies are mutual best responses. Pure strategy Nash equilibria were discussed in class. The mixed strategy Nash equilibrium is p = 0.29, q = 0.91 (Rajbhandari and Snekkenes 48). Finding mixed strategy Nash equilibria was another topic discussed in class.
The bookstore has a high probability of exploiting a user’s information. This finding would be useful from a user’s perspective because they would know that this bookstore is unlikely to protect their privacy. They could take steps to protect their own privacy, such as giving fake information as the user in this game could. They could also refuse to do business with this bookstore, ensuring that none of their data ends up being exploited. Game theory, particularly topics already covered in class like two player games and Nash equilibria, can therefore help people to take more control over their own privacy.
Reference:
https://link.springer.com/content/pdf/10.1007%2F978-3-642-20769-3_4.pdf