In Ex Machina Nathan is a genius tech innovator. Does it make sense that he would use keycards to limit access to the different rooms of the house and his computer instead of biometrics or a more secure or advanced method?

  • Firstly, biometrics are not very secure. That's a bad assumption. Secondly, what do you mean by "more advanced"? Maybe he designed his own top-of-the-line encryption algorithm and created a private network with cutting edge server technologies. If you're thinking of something more science-fantasy a-la star wars/trek, note that this is a much harder (down to earth) form sci-fi than those.
    – ViggyNash
    Jan 9, 2018 at 4:03

1 Answer 1


Yes, to avoid the locks being hackable via the network.

A centralized system using biometrics or other methods could potentially be vulnerable to an AI -- or inquisitive visiting programmer -- that got access to the network. The keycards would simply be high-tech keys with access individually coded into each of the locks.

Plus, it's entirely possible Nathan had a less-than-optimal system installed specifically to help with some sort of manipulation of Caleb, since we eventually learn the whole experiment is a setup.

(From a narrative perspective, forcing Caleb to physically acquire a key card puts him in more peril, and is more visually interesting. As we later learn, stealing the card gave him access to an interface in Nathan's chambers where he was able to revise the security protocols. A fully secure system would have required a more convoluted method for Caleb to turn the tables on Nathan.)

  • 4
    The first half of your answer doesn't make sense to me. A key card just holds an ID or similar. It's sent over the network and checked against a database, usually, just as biometrics would be. The second half of your answer is spot on, though. Jan 6, 2018 at 2:59
  • 1
    @user1118321 Most keycard systems work that way, but they don't have to. Each card could contain an RFID chip (or any technology to create a unique signature of some sort); each door lock could be individually coded as to which card signatures to accept. No networking required; of course, it means each door has to be individually updated. (There is a mechanical keycard system where the keys have either depressions or holes and the locks have a series of pins that only work if the keycard has the correct holes. Each lock can be customized by swapping in a plastic template.) Jan 6, 2018 at 6:35
  • His point still stands though. You could argue that even with biometrics, you could build all of the processing components into the door lock interface and code your biometrics to each door separately. But even then, I don't see the need. You can always just create a private network within the facility. Much easier, much more secure.
    – ViggyNash
    Jan 9, 2018 at 3:57

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