Assuming that someone is able to telepathically intercept thoughts and words in my mind, what mechanism will allow me to authenticate securely? A solution that does not yield to physical search or subpoena is welcomed but not necessary.

So for example, a /dev/random generated file on a pendrive is one solution (unless seized, but that isn't a passive attack), fingerprint reader is another (unless ordered by say court, also hard to duplicate without the person). Any other ideas?

Yes, this is a legitimate question. It is not quantum cryptography but please take this seriously.


4 Answers 4


Considering that mind-reading technology is still far from being able to read passwords from your mind, this question is largely hypothetical.

But when "something you know" is unsuitable as an authentication factor, there are two others you can use:

  • Something you are, also known as biometry (fingerprint, iris scan, DNA sample...). These come with their own set of problems, though.
  • Something you have, like a smartcard or USB token.

I suppose I'll indulge this. One solution to something like this would be to have a multi part key like bitcoins so-called "multisig keys" held in different legal jurisdictions.

  • Interesting. This does protect against a subpoena, but how do you effectuate this? If there is an another person holding a key, how do you authenticate yourself in front of that person? And make room for a possibility that this person is under same kind of interception. I grant you that computers on both sides may be secure, and Diffie Hellman creates a secure connection.
    – ArekBulski
    Jul 23, 2016 at 20:45

The simplest way to solve this would be with some form of second factor authentication. A method for making that immune to subpoena isn't immediately obvious.

While telepathy is rather unlikely, as I understand current technology, hypnosis or other methods could be used to "pick someone's brain". So the scenario described isn't entirely ridiculous.

  • Sam Harris openly says that currently MRI technology allows to work as a pretty good lie detector, so the tech is pretty close actually. Does not work remotely tho. And thank you for saying so (scenario described isn't entirely ridiculous).
    – ArekBulski
    Jul 24, 2016 at 8:30

A Yubikey is specially made for this. It's a kind of two-factor authentication USB-stick which generates and syncs pseudo-random passwords after a given amount of time.

That way, even you don't need to know your 'second Yubikey-password' and don't even need to think about it.

  • can't they force you to give up the master key?
    – dandavis
    Jul 25, 2016 at 15:42

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