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Engendering Alice and Bob

Quinn DuPont and Alana Cattapan

09 October, 2017

News broke last month that China had successfully held the world’s first “unhackable” videoconference between research centers in Vienna and Beijing, made possible by previous efforts that teleported (yes, teleported) a photon, relayed from a ground station to a satellite in Earth’s orbit. As science writers and journalists struggle to describe the complex process of “quantum entanglement” that made photon teleportation possible, they inevitably do so using the familiar characters of Alice and Bob.

Alice and Bob are fictional characters originally invented to describe information exchange in public-key cryptography. Today, references to Alice and Bob can be found in many other fields, such as economics, physics, engineering, logic, and computer science. In fact, Alice and Bob often stand in for any sort of exchange. Alice may want to send a private message to Bob, but sometimes Bob is selling stocks to Alice, or Alice and Bob want to play poker via mail, or Alice and Bob are trying to engage in complex processes of quantum mechanics. Alice and Bob have become ubiquitous characters because they are used as proxies to make complex, seemingly abstract concepts accessible (or more accessible to broader audiences).

Alice and Bob are everywhere, but they embody, as they always have, conventional understandings of gender and sexuality in science, technology, and engineering. They originated, somewhat innocently, in the well-known “RSA paper” (on public-key cryptography) as a way to differentiate between sender and receiver, originally “A” and “B,” and by gendering the characters, the authors were able to simplify the descriptions, to “he said,” “she said.”

More recently, the lives and backstories of Alice and Bob have been filled in with stereotypical assumptions about gender, race, class, and identity. Typically, these central figures of contemporary science, technology, and engineering are depicted as a nuclear, heterosexual, white couple—or at least, a man and a woman—and whose depictions have largely gone uncontested. A 2013 cover of Physics World magazine, for example, has a blonde Alice concerned about navigating “the quantum world,” saying to her square-chinned companion, “Oh, Bob! It’s looking spookier than ever.” (One letter published in response to this cover does challenge this rendering of Alice as a “cowering subordinate,” suggesting that she could have said instead, “It’s fascinating, Bob! Let’s investigate!”). In other cases, Alice and Bob are a recently divorced couple, or Alice doesn’t trust Bob.

Other characters have since been added to their universe, including Eve, the eavesdropper, and the malicious attacker Mallory; characters that are often portrayed as disrupting Alice and Bob’s imagined domestic bliss. For example, the videos developed for the 2011 RSA conference—organized around the theme of “Alice and Bob”—told the story of Alice and Bob’s first date interrupted by Eve’s meddling and Mallory’s attack. An XKCD comic (depicted to the left) also riffs on this theme, with Eve lamenting that she is always painted as an “attacker,” but it is Alice who sent the private message, and Eve who has suffered.

Alice and Bob offer an important example of how digital culture may inadvertently embody and perpetuate conventional understandings of gender and sexuality. The inside jokes and winking nods about Alice and Bob’s romantic life unnecessarily reinforce gender norms in fields where women are already few and far between. The perpetuation of gendered stereotypes is particularly troubling in the cybersecurity industry, among the least diverse of the technology industries (a sector already worse than most). This labour imbalance persists, even though women were particularly important to the early development of cryptography (and later pushed out). There are a lot of reasons why women are underrepresented in science and engineering (and many initiatives to address them), but portraying women as romantic objects and homewreckers surely doesn’t help.

The history of Alice and Bob is, in many ways, a history of the present. The gendered constructions of those we imagine to be actively engaged in science, technology, and engineering inform who will sees themselves in these fields, who can imagine themselves there, and who belongs. It is a simple but necessary argument: representation matters. Representation in how we think about quantum communication matters and Alice and Bob matter. And as new innovations are made in science, technology, and engineering–and as we seek out ways to explain them—let us be attentive to the cultures we create to depict gender and sexuality.


For the complete history of Alice and Bob, see Quinn DuPont's and Alana Cattapan's research website at cryptocouple.com, or attend their presentation at SIGCIS 2017 in Philadelphia (Oct 29, 2017).

Quinn DuPont is a Research Associate at the Information School at the University of Washington. @quinndupont
Alana Cattapan is an Assistant Professor at the Johnson Shoyama Graduate School of Public Policy at the University of Saskatchewan. @arcattapan

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Backchannels / Reflections

Commentary on the current and future state of the field or subfields within science and technology studies. Can include interviews, meditations on particular concepts or methods, biography / autobiography, essays, and other more personal and less formal writings.