Over the years, it’s safe to say our name has drawn a fair bit of attention. Indeed, It’s a rather peculiar name. It doesn’t sound like a typical quantum company, or any company for that matter and contrary to what many people assume, our founders are not called Alice nor Bob. So we thought it might be time to clear things up and explain why we have this atypical name.
Our name is a nod to the scientific culture and tradition that came before us, and we’ll give a short overview in this blog. But ever since then, it’s also become an essential part of our DNA. If you know us, just try to imagine Alice & Bob with another name that is not Alice & Bob… We definitely can’t. So, get ready for the brief history of Alice and Bob, and why we borrowed their names.
The birth of Alice and Bob in cryptography
If you’ve studied cryptography, computer science or physics, you’ve almost certainly come across Alice and Bob. But it was in the field of classical cryptography where the two characters were born. They were first popularized in a paper about RSA encryption by Shamir, Rivest, and Adleman, the main cryptographic system still used today around the world to keep communication secure. You encounter RSA every day, since it protects most of your passwords and information, from your bank account to your email, but it is so secure even top state secrets are protected that way. In the paper, the authors invented the characters Alice and Bob to explain the communication scenario and the workings of their technology. Before, it had been standard to use just the letters “A” for the sender and “B” for the receiver. Now the sender and receiver were like real people with real names, and naturally, it made the science more teachable. And it caught on…
From there, the names Alice and Bob were adopted as the classic placeholders for explaining cryptography and secure communication in textbooks, lectures and research papers. The cast of characters expanded too, with different actors you might find within a communication scenario and their different intentions, often with a name that denoted it.
Recurring characters include Eve, the “eavesdropper” or Mallory, the “malicious” and many more. Soon, other scientific fields beyond cryptography adopted these fictional characters for their own explanations and teachings, notably physics and quantum mechanics.
Alice and Bob in physics
In the early 1980s, physicists started imagining a world where eavesdropping was not just hard, but physically impossible. In the first quantum key distribution protocol (BB84), Alice sends Bob single photons, each encoded in different quantum states. If Eve tries to peek, the laws of quantum mechanics guarantee she will disturb those photons, leaving detectable errors. For the first time in the history of communication, security didn’t rest on mathematical puzzles or faster computers, but on the fundamental rules of nature themselves.
Shor’s algorithm
Fast forward to 1994, the first quantum algorithm, Shor’s algorithm, was invented. This brought huge potential implications for secure communication, though back then, the quantum computer on which this algorithm would need to run was still highly theoretical. Shor’s algorithm would enable a quantum computer to factor very large numbers, something impossible for classical computers in any reasonable time, and that matters because factoring large numbers is exactly what you need to do to break RSA encryption. So, the same RSA protocol that helped make Alice and Bob famous in classical cryptography and communication is also the one that quantum computers would be able to break, as soon as we’re able to build ones powerful enough to run Shor’s algorithm. The story comes full circle.
Our identity
Unlike the characters Alice and Bob, we write our name slightly differently, Alice & Bob with an ampersand. As you can see if you’ve got up to here, Alice & Bob is a reference to the rise of quantum information and algorithms like Shor’s, and an ode to cryptography and computer science where it all started. This also explains why many people from a science background mistake us for a cryptography company when they first hear about us.
Besides, a good story is timeless, and fictional characters can be helpful tools just as much for explaining how science works as they can for telling a story in a work of literature. As we build and communicate our science, this is exactly the spirit we want to bring on.
Incidentally, it also happens to be a great conversation starter, opening the door to questions and explaining what we do.
Alice and Bob began their life as personas in a story to explain a key innovation in cryptography, since then they have become staple members of science folklore. Our goal is to do justice to this very science that made it possible for us to exist, by working on one of the next biggest challenges in science: building a large-scale quantum computer.
