Hello, world.

This is the CS50 podcast, episode 5, 0 indexed.

My name is David Malan, and I'm here with CS50's own Colton Ogden.

COLTON OGDEN: Glad to be here--

interesting thing to start us off-- so, we've talked about robocalls a lot

in the recent past, multiple episodes.

And I think we touched briefly upon the prospect

of finding a solution to this problem.

You know, people are getting robocalls all the time,

even though, in the last couple of weeks,

I have noticed the numbers sort of dropping, at least for me, personally.

I still get the occasional call from a presumed spoofed caller.

DAVID MALAN: Yeah, sorry about that.

COLTON OGDEN: But, apparently, the FCC--

Ajit Pai has proposed a ruling that would actually

allow phone companies to block these unwanted calls, these spoofed calls,

before they even get to potential customers.

DAVID MALAN: Yeah, no, this is a nice initiative.

It's perhaps a little belated at this point, certainly.

Because, as we've discussed, these robocalls, these automated calls,

have really been proliferating, in large part

because of the software via what you can do this,

and the API access which you can do this.

But I think the fundamental problem, frankly,

is that the phone system that we have today

really is not all that fundamentally different from what we've

had for decades now, which is to say that there's

no authentication of these calls in the first place.

The systems generally just trust that the number being presented in caller ID

is, in fact, the number from which a call came.

And that's, of course, not always the case.

COLTON OGDEN: Right, and the--

I guess the proposed sort of authentication system that they're

going to roll out is called Shaken Stir, which is very akin to what James Bond's

says when he orders a martini.

But the acronym is a--

basically, the shaken part of it is signature

based handling of asserted information using tokens.

And then the stir part would be secure telephone identity revisited.

DAVID MALAN: Indeed, it's a wonderful acronym

if you allow yourself to use arbitrary letters from some of the words.

COLTON OGDEN: Yeah, and it's a bit of a mouthful.

But this is cool, because this suggests that we'll actually

get what you just alluded to, a way of actually signing calls and making sure

that people who present themselves as xyz are in fact xyz and not,

you know, sort of proxying themselves or presenting themselves

as some other entity.

DAVID MALAN: Yeah, I mean, much like the web-- thankfully

we got that right, presumably because of lessons learned from things

like telephony over the years.

Of course, the phone system has been around for so long now

that it's certainly hard, I imagine, to shoehorn

in some of these more technological features

without breaking some of the intermediate points

or some of the last miles, some of the folks

who are on the other end of the line that might not necessarily have access,

in their municipality, to the latest hardware.

So, I'll be curious to see how this evolves.

I mean, to be honest, this might all become moot over time

if phones themselves, or phone numbers, are perhaps

replaced by more data based services.

I mean, right now, we're very much in the phase

of commercial services like WhatsApp, and iMessage, and so forth.

I mean, but those have started to supplant already things like SMS,

so, frankly, maybe the solution is ultimately

just going to be too late in coming if the world moves to something else,

anyway.

COLTON OGDEN: Yeah, I imagine, when folks were developing the phone system

we have in place, they weren't expecting the ability for somebody

to arbitrarily code and script, en masse, the sort of behavior

that we're experiencing now.

DAVID MALAN: Yeah-- hey, back in the day, it used to be based--

at least pay phones-- on actual sounds, right?

There are so many documented cases, and I

think Steve Jobs and Steve Wozniak were among the folks involved

in this back in the day, where you could have a little box that would generate

the appropriate sounds that mimicked what the sound was if you

put a quarter or a dime into a phone.

So, you could effectively make free long distance phone calls

by spoofing those sounds.

So there, too-- there was a sort of an assumption of trust

that was quickly broken.

COLTON OGDEN: I think the theme is always that, if there is a system,

humans will find a way to abuse and break it.

DAVID MALAN: Indeed, but there are some really real world implications of this.

In fact, just the other day did I see an article

online about what have been called virtual kidnappings which, frankly,

is literally ripped out of a "Law and Order" episode

that I'm pretty sure I've seen, which is ironic,

because usually it's "Law and Order" ripping

things out of the actual headlines.

But this, I think, predates this, whereby

folks have started to get, terrifyingly, what

appear to be actual phone calls from their child's phone

number, or relative's phone number, or a co-worker's phone number,

and on the other end of the line is some adversary, some human who

is pretending to have actually kidnapped the person whose phone they're

purporting to be calling from when, in reality, they're just spoofing

that number and tricking someone into thinking that they've actually

physically hijacked their phone number and kidnapped that person.

COLTON OGDEN: Yeah, presumably, I mean, with this new ruling, hopefully,

you know, this sort of horrendous situation

doesn't end up becoming common at all, or at least it

gets completely remediated.

DAVID MALAN: Yeah.

COLTON OGDEN: Because this is one of the more terrifying examples of how

to abuse spoofing.

DAVID MALAN: No, absolutely.

And it's horrifying that it's gotten to this point

but, you know, what you might think is kind of a cool hack,

the ability to spoof your phone number, really

does have some non-trivial implications.

And especially, for most folks out there, you know-- myself,

before I even thought about this the other day after reading the article--

you might not even realize that this is possible

and what the implications, therefore, are of these sort of bugs at best or--

bugs at worst, or missing features at best.

COLTON OGDEN: Yeah, I mean I think if this even happened to me,

I think my initial inclination would be to believe it.

I mean, certainly it would be terrifying,

and you wouldn't want to take any risks and assume

that whoever's on the other end of the line

is actually bluffing you or telling the truth.

Now, speaking of ransoms, unfortunately, I

think these have cropped up in other contexts in the news of late

and for the past couple of years, in fact.

DAVID MALAN: Yeah, no.

I mean, there have been multiple cases, WannaCry being very prominent in 2017,

of these sort of worms that infect people's systems

and, you know, potentially encrypt the hard drive, or do other things,

and request that, in order to have this fixed,

the end user end up paying some amount of money,

either bitcoin or actual money, to decrypt their hard drive

or do whatever needs to be done to unlock their system.

COLTON OGDEN: Yeah, no, and that's the problem with worms, and viruses,

and just malware, malicious software in general,

is that, if it has the same privileges that you, the user, who accidentally

installed it, somehow do--

or worse, it has administrative or root access

to the computer-- it can do anything with your system and the data.

You know, it almost makes exploits like sending spam automatically,

unbeknownst to you, from your computer seem like completely delightful

in comparison because, now, these most recent forms of ransomware

are indeed doing exactly that.

They're actually running algorithms to encrypt the files

on your own hard drive and then not telling you,

the owner of those files, what the key is, the sort of secret

with which they were encrypted.

And, so, in this way can the bad guys literally say,

hey, pay us some number of dollars or, in practice, some number of bitcoins

in order to get access to the key via which you can unlock your data.

Who knows if you're even going to get the key.

I mean, frankly, an even more compelling ransomware

would be to just encrypt the data and throw the key away.

Then you don't even have to communicate further with the person

once you get that fund.

DAVID MALAN: Yeah, and, in light of this sort of horrible new trend

of ransomware that we've observed over the last few years,

there are companies that do try and take advantage of this and will say,

you know, we will help you decrypt your system.

We will use high tech, quote unquote, solutions to reverse this ransomware.

But it turns out that some companies, instead

of actually having the algorithms and the technology to do this,

are paying the actual people responsible for the ransomware

directly and then charging you a premium.

COLTON OGDEN: Yeah, no, this is really kind of a tricky thing,

and I'm reminded of most any Hollywood movie, where someone is taken hostage.