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Why is that?
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Well, as you might know, in your phone is typically
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a SIM card, either a physical card, a little chip, or nowadays
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it might actually be built into the phone as well.
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But that SIM card has a unique identifier.
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And when you sign up for phone service, typically, with a company,
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they need to know what the unique identifier is of your SIM card,
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be it something physical or something wired, hardwired into your device.
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Why?
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Because that's how they associate your phone number with that specific device.
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The catch is that it's all too possible, and in some cases, all too easy,
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to trick, even the phone companies, into swapping your SIM not necessarily doing
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it physically per se, but convincing the mobile phone
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carriers to update their system to say, oh,
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David now has this SIM card and not that original one.
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That is to say, if I'm an adversary and I just
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have any old phone with any old SIM card,
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and I figure out what the unique ID is, and maybe I call up
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David's mobile phone provider, and I somehow convince them
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that I am David by tricking them into believing it's me, as by telling them
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all of that personal information about myself,
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I might be able to convince them to swap my SIM card,
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the adversary's, with what is already on file.
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The implication of that is that when David subsequently gets text messages,
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they don't actually go to me, the real David.
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They go to the adversary's phone as well because they're tied to that SIM card.
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So in general nowadays, if you have a choice,
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using some website or app to use SMS or text-based messaging
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versus a native application that you install
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onto your phone or other device, you should generally
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prefer the latter, some first-class piece of software
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that actually uses push notifications or your data plan
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and does not rely on SMS text messaging because of this potential threat.
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So what are still other threats when it comes to these systems?
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Well, it turns out that it's very possible, unfortunately,
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for adversaries to somehow get software, malicious software,
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otherwise known as malware, onto your Mac, onto your PC,
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perhaps even onto your phone .
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This might be because you installed a piece of software
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that you shouldn't have trusted.
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This might be because your phone or your device
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is infected with something like a virus or a worm.
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But in general, you might be vulnerable to malware,
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including software that logs all of your keystrokes.
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Key logging refers to exactly that, some piece of software
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that most likely maliciously is literally recording everything you type
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or everything you tap into that device.
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And what is this software do with those keystrokes?
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Very often it will upload them.
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If there's an internet connection, maybe to a server
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that the adversary controls.
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Now, what's the implication of this key logging threat?
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Well, if you're typing in your username, that's not such a big
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because those are generally public.
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But if you're typing in your password, and that's
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being automatically uploaded to the adversary's server,
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now they know your username and your password.
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Worse, if the adversary also sees you typing
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in that six-digit code, your one-time password
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that you might have received even from your phone or some other device,
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if they are fast enough and smart enough and figure out
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how to log what you're typing, send it to the server, perhaps even before you
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yourself hit Enter, maybe they can use not only your username
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and your password, but even that one-time password
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by pretending to be on their own phone or their own laptop or desktop,
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typing in or more realistically, automatically
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through software typing in those same values
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and accessing your account even before you had a chance to do so as well.
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Now what are the defenses against that particular threat?
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Really just to be generally paranoid about what computers you yourself use.
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For instance, nowadays I will rarely, if ever,
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actually use an internet cafe's computer or even a lab computer
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here on Harvard's campus, or frankly, even a friend's computer
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because I don't know just how safe they are when it comes to best practices
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using their device on the internet.
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I will in general only log into websites and apps
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on my own personal devices, which isn't to say that I, too, am perfect,
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but rather at least I'm reducing the probability
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that I lose control over my data by using some other device that I myself
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don't oversee by that person, that owner,
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not themselves adhering to best practices.
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Now, even then, I will admit, that using key logging
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and getting it up to an adversary's server
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and inputting it faster than you might is a pretty sophisticated and difficult
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threat.
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But it's worth keeping in mind and realizing that these are certainly
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theoretical attacks.
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And if you yourself are targeted for some reason,
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these are absolutely things you should be mindful of.
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So in general, if you have the luxury of only using your own device
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and not some shared device that, too, tends to be best practice, I would say.
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Any questions on these here attacks?
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AUDIENCE: Regarding using long passwords,
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do you recommend using Google passwords or Apple passwords for the system
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to remember the passwords for us?
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DAVID MALAN: A really good question.
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Short answer, yes, but we'll come to that
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in more detail in just a few minutes.
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So what are other attacks that we should be mindful of?
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So this one has kind of a funny name, but there's this attack
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