HackPrinceton Piano Stairs - V2, Bonnie

Creations by Princeton students from HackPrinceton’s November hackathon

Jackson Dobies ’14

The following four “hacks” offer a sampling of the applications developed at HackPrinceton’s fall hackathon. A full list, with descriptions, can be found online on the HackerLeague event page.

Touch ID Password Manager:

An application that allows iPhone 5S owners to use the fingerprint sensor on their phones to sign in to password-protected websites like Facebook and Gmail.

Created by computer science major Pranav Gokhale ’15, the application replaces the “master password” to a password manager (a program that stores an individual’s various pieces of sensitive information in one place) with a user’s fingerprint. Gokhale built the application because he is passionate about information security and — like most college students — he has trouble remembering his own passwords. “I am never going to forget my fingerprint,” he said, grinning, after winning second place at HackPrinceton. In addition to being more convenient, Gokhale says his fingerprint system is safer than a password because an adversary has to have two basic factors (computer science jargon for the combination of an iPhone plus a fingerprint) rather just a single password in order to break in.

What Would I Say?:

“A Facebook App that generates statuses so that you don’t have to” ­— at least that’s how UK news outlet The Independent described this HackPrinceton creation, which went viral shortly after the competition ended.

The app, developed by a team of Princeton graduate students, surveys your Facebook profile and generates status updates based upon what you have posted in the past. You can also query publicly accessible pages, such as the Princeton University or PAW Facebook pages:

“Remember, kids — Princeton Alumni on new York City subway is NOT the Woodrow Wilson Award”—PrincetonUniversityBot  

“However, these ubiquitous creatures are recruited using scholarships."—PrincetonUniversityBot

“Tiger of the Week by Princeton's grading policies. Is it so important?”—PrincetonAlumniWeeklyBot

As a result of the enormous popularity of What Would I Say, it’s difficult these days to log in and not see a deluge posts generated by the app. (The site received over 1 million hits within 3 days of launching.) It took home the prize for Best Facebook Integrated Hack at HackPrinceton and has since been featured in The New Yorker, Business Insider, Wired, The Los Angeles Times, and The Telegraph.


A Web service that allows you to access online content in a way that nearly guarantees your privacy (albeit at the expense of browsing speed).

Unlike most hackers at HackPrinceton, freshman Walker Davis built Fintoil not for commercial appeal but out of concern over the present state of Internet privacy. Fintoil is named after the tinfoil headgear associated with extraterrestrial paranoia, and Davis says that it’s so secure that not even the NSA can tell what the user is reading. All you have to do is send an email to Fintoil with the body containing details of the content you want to retrieve and Fintoil will email you back with the content encrypted to avert any potential surveillance effort — a noteworthy accomplishment according to Professor Ed Felten, director of Princeton’s Center for Information Technology Policy, who helped judge the hackathon.

Piano Stairs:

An interactive portable piano that, once setup, translates the steps of a staircase into the keys of a piano.

The Piano Stairs team, led by senior Bonnie Eisenman, installed sensors on a staircase in the Friend Center, where HackPrinceton was held. A video clip demonstration of the Piano Stairs can be found below. Along one side of the stairs are light sensors. On the other are flashlights. A device called an Arduino determines when a step occurs by analyzing the interference with the flashlight and sends that information to a miniature computer, which handles producing the actual sounds. Piano Stairs won second place in the hardware category.