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SPEAKER 1: Follow us
for the funky behavior.

2
00:00:02,580 --> 00:00:05,070
Make a note on the record we gave you.

3
00:00:05,070 --> 00:00:07,560
Feel free, drop your
pants, check your hair.

4
00:00:07,560 --> 00:00:10,080
Do you like the garments that we wear?

5
00:00:10,080 --> 00:00:15,030
I instruct you to be the obeyer,
a rhythm recipe that you savor.

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00:00:15,030 --> 00:00:19,860
Doesn't matter if you're minor or major,
just to try of the game with a player.

7
00:00:19,860 --> 00:00:21,693
And you Inhale like a
breath of fresh air.

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00:00:21,693 --> 00:00:24,360
SPEAKER 2: First thing we're going
to need is a lot of pictures.

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00:00:24,360 --> 00:00:26,790
Unfortunately, Harvard doesn't
keep a public centralized Facebook,

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00:00:26,790 --> 00:00:29,665
so I'm going to have to get all the
images from the individual houses

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00:00:29,665 --> 00:00:31,510
that people are in.

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00:00:31,510 --> 00:00:32,770
Let the hacking begin.

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00:00:32,770 --> 00:00:35,770
First off is Kirkland, they keep
everything open and allow indexes

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in their Apache configuration
so a little Wget

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magic is all that's necessary to
download the entire Kirkland Facebook.

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Kids' stuff.

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Next is Elliot, they're also open
but with no indexes on Apache.

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I can run an empty search
and it returns all the images

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00:00:47,590 --> 00:00:48,997
in the database in a single page.

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And I can save the page and Mozilla
will save all the images for me.

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Lowell has some security, they
require a username and password combo.

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00:00:54,790 --> 00:00:57,370
And I'm going to go ahead and say they
don't have access to the main SAS user

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00:00:57,370 --> 00:00:57,830
database.

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00:00:57,830 --> 00:00:59,747
So they have no way of
detecting an intrusion.

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Adams has no security but limits
the number of results to 20 a page.

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All I need to do is break out the same
script I used on Lowell and we're set.

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Dunster is intense, not only
is there no public directory,

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but there's no directory at all.

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You have to do searches--

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[YELLING]

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You search for things more--

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DAVID MALAN: Hello, world.

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This is CS50 Live, and boy do we
have a good show for you today.

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That of course was acclaimed
film, The Social Network.

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And then of course, was
my acclaimed colleague

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CS50 Zone, Ramon [? Galvan, ?]
who you may recall from such films

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as season zero, episode five.

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Now, whether or not you
knew it, all these years

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you've been doing what's called two
dimensional printing using an Inkjet

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or Laserjet printer.

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It turns out, though, that
all the rage these days is

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a new technology known as 3D printing.

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Whereby, you can actually print
three dimensional objects.

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There's any number of
technologies via which

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you can print in three dimensions,
one of which is called FDM.

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And we recently sat down
with CS50 Zone and sealed off

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to talk about how we in
CS50's production team

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could solve an actual problem.

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Let's take a look.

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ANSEL: Hi, my name is Ansel, I'm
a senior in mechanical engineering

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here at Harvard School of
Engineering and Applied Sciences

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and I'm a member of CS50's team.

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So 3D printing is a
rapid prototyping method

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that allows us to design a
part in a CAD modeling program

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and then print it out
painlessly and very rapidly.

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There are a few different 3D
printing methods that we often use.

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Stereolithography being one of
them and FDM being another one.

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FDM stands for fused
deposition modeling,

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which is just a fancy way of saying
that the printer extrudes some molten

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material, often plastic,
onto a plate in layers.

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So when we design a part
like a cube, for example,

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the printer will just
print it layer by layer

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until it's completed the structure.

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Oftentimes, we'll design the part to
be solid, but printing a solid part

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is both time and material inefficient.

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So there's some algorithm
within 3D printer

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that creates a honeycomb internally
that maintains the parts' rigidity

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but doesn't use a ton of
time and a ton of material.

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Here's one of the cameras
that we use at CS50.

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And you'll notice that there's this
massive lens attached to the end of it.

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If we just let this lens be supported
only at the attachment point

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to the camera, it's a big cantilever and
it puts a lot of stress on this joint.

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So what we will often do
is use a support like this.

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So this support, as you can
tell, has two holes in it.

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And it's designed to
slide onto these rails

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and there's a support slider, I
guess, that just pops up and attaches

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to the bottom of this camera.

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Because this camera is a little
bit taller than what we're used to,

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this support is too short and
it won't actually meet the lens.

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So if I were to slide it
onto the rails, there's

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a big gap between the top of the
support and the bottom of the lens.

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So this is a perfect opportunity
for something like a 3D printed part

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to mate the lens and the support.

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We can design it pretty easily, take a
couple of measurements from the camera,

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and then print out a part that
will adapt our support to our lens.

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So here's a modified support piece
that I printed and I had just

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00:03:45,450 --> 00:03:48,420
simply designed this black
support structure that

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has these crosses in it to screw on to
our support that came with the camera

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and then mate the lens with this
curved structure at the top here.

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So we can slide this on and
then move this piece up and down

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until it supports the lens completely.

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It's a pretty simple solution
to a pretty simple problem,

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and we were able to
make it very rapidly.

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This part took under an hour to
print and it took maybe 10 minutes

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00:04:08,610 --> 00:04:11,370
to cat up, so pretty easy solution.

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If this part were machined out
of maybe aluminum or steel,

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it would have taken several
hours of tedious machining

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for a part that would
end up being ultimately

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overbuilt and overkill for the problem.

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So here's a great example
of how 3D printing works

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DAVID MALAN: And now for a
new segment, we like to call--

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[LOUD BANGING]

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Yes, indeed.

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Samsung and other
manufacturers have been

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producing of late something
called smart TVs, which generally

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mean that they have an
internet connection, so

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that they can download
TV guide information

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and other interactive content.

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Unfortunately, it also
means that these TVs

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tend to have other hardware
as well, including microphones

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00:04:49,930 --> 00:04:53,440
so that you can upon hitting a
button on the remote or speaking some

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00:04:53,440 --> 00:04:57,160
spoken command trigger your TV to
start listening to you at which point

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it uploads your words
to Samsung servers,

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analyzes them, and then
responds accordingly

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00:05:01,840 --> 00:05:04,280
on the TV to your voice commands.

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In other words, if you're sitting at
home watching TV in your living room

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or if you're lying in bed watching
TV in bed, Samsung is there with you.

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Now, it turns out that
recently came to light

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is this clause here from
Samsung's own privacy policy.

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Please be aware that if
your spoken words include

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personal or other sensitive
information, that information

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will be among the data captured
and transmitted to a third party,

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in this case Samsung.

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Now thankfully a day later, Samsung
responded with this reassurance

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on February 6th.

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Samsung takes consumer
privacy very seriously.

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In all of our smart TVs, we employ
industry standard security safeguards

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and practices, including
data encryption to secure

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consumers' personal information and
prevent unauthorized collection or use,

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00:05:51,280 --> 00:05:52,540
whew.

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In fact, what Samsung has been doing is
this as came to light a few days later,

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all of those voice commands that you
might be speaking into your smart TV

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are being transmitted to this
address here, nuancemobility.net.

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And thankfully, at
least at first glance,

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they're being transmitted
on TCP port 443, which

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generally indicates that the connection
is secure because it's using HTTPS.

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Unfortunately, this is just a convention
that encrypted data is generally

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sent on port 443.

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You can send any data you
want, and indeed, Samsung

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is taking advantage of that opportunity.

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It turns out that some security
researchers at a company

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called Pen Test Partners.

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Using open source software called
Wireshark, listen to the traffic

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that was being sent from one of their
Samsung Smart TVs to Samsung's servers

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and what they discovered was this.

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A bit cryptic to be
sure at first glance,

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but it is nonetheless clear text.

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This is a markup
language, not unlike HTML,

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called XML inside of which
is some encoded audio data.

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00:06:48,130 --> 00:06:49,990
And sure enough, these
same researchers were

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00:06:49,990 --> 00:06:52,960
able to decode that
audio data, ultimately

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00:06:52,960 --> 00:06:57,610
revealing their own spoken words being
sent in the clear over the internet

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00:06:57,610 --> 00:06:58,600
to Samsung.

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Indeed their conclusion was this,
so it does kind of spy on you,

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00:07:02,470 --> 00:07:05,660
but then leaks the spy data
out onto the public internet.

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Now thankfully, Samsung
has responded as follows.

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Samsung takes consumer
privacy very seriously

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and our products are designed
with privacy in mind.

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Our latest smart TV models are equipped
with data encryption and software

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00:07:19,810 --> 00:07:23,920
update will soon be available
for download on other models.

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And now for another stressor, it
turns out the computer manufacturer

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00:07:27,490 --> 00:07:29,770
Lenovo has been doing the following.

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Pre-installed for quite
some months has been

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software called Superfish,
which ostensibly

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00:07:35,680 --> 00:07:39,550
is designed to inject additional
search results into images that you

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00:07:39,550 --> 00:07:42,760
might be searching for on something
like Google images or the like.

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Thereby, providing you effectively
with some advertisements or links

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to related information.

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Unfortunately, Superfish has been
doing this by breaking how HTTPS works.

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In other words, if you normally visit
a website that is encrypted with HTTPS,

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you'd hope to see a URL bar like this.

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This for instance is a US
Bank called bankofamerica.com.

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And indeed, that green URL bar and
the fact that it starts with HTTPS

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is generally a good
thing, because it means

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you have an encrypted connection between
you and bankofamerica.com's websites.

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And if you were to look at
the SSL certificate being

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used for this encryption by some
sequence of commands in your browser,

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you would hopefully see
a window not unlike this.

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And if you focus in on there on
who issued the so-called security

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certificate, you would hopefully
see a reputable party like VeriSign

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who signs many of these so-called
SSL certificates in the world.

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Unfortunately, if you
own a Lenovo computer as

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this researcher here did
and with his camera phone

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took a photo of what he saw.

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He saw this window here, which
if we focus in on that same line,

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the security certificate being issued
by Bank of America that he received

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was apparently issued by
Superfish Inc. In other words,

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the software that's being
pre-installed on these Lenovo computers

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is effectively pretending to be
bankofamerica.com, gmail.com,

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facebook.com, any number of websites
that normally have their own security

192
00:09:02,440 --> 00:09:03,070
certificates.

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00:09:03,070 --> 00:09:06,070
But no, Superfish is
instead masquerading

194
00:09:06,070 --> 00:09:09,220
as a so-called man in the middle
presenting its own security

195
00:09:09,220 --> 00:09:12,880
certificates as though they belong
to Bank of America and the like.

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Indeed, if you start poking around
the so-called root certificates

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00:09:15,790 --> 00:09:17,890
on your Windows computer,
you might see a line

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like this, which indeed indicates that
one of the root certificates, the most

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00:09:21,280 --> 00:09:25,970
powerful in a computer, it was in
fact installed as Superfish's own.

200
00:09:25,970 --> 00:09:29,810
So not only is this bad in the context
of this software on your own computer

201
00:09:29,810 --> 00:09:32,690
potentially spying on your
otherwise encrypted traffic,

202
00:09:32,690 --> 00:09:36,860
it also means that so can anyone
else nearby you in Starbucks

203
00:09:36,860 --> 00:09:40,190
or an airport alike where there's
some Wi-Fi, because every Lenovo

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00:09:40,190 --> 00:09:42,740
computer that has the
Superfish software also

205
00:09:42,740 --> 00:09:47,000
has the same public and private key,
which means even if some other Lenovo

206
00:09:47,000 --> 00:09:51,350
computer is in fact encrypting data,
albeit with Superfish's certificate,

207
00:09:51,350 --> 00:09:55,460
then that data is being sent
over the Wi-Fi encrypted.

208
00:09:55,460 --> 00:10:00,470
But so can anyone else on that
connection, decrypt that same data

209
00:10:00,470 --> 00:10:02,450
because they of course,
have the same key.

210
00:10:02,450 --> 00:10:06,050
Now thankfully, Lenovo has
since responded as follows.

211
00:10:06,050 --> 00:10:09,680
Superfish was previously included
on some consumer notebook

212
00:10:09,680 --> 00:10:14,330
products shipped between September
2014 and now February 2015

213
00:10:14,330 --> 00:10:16,220
to assist customers
with discovering product

214
00:10:16,220 --> 00:10:17,870
similar to what they are viewing.

215
00:10:17,870 --> 00:10:21,580
However, user feedback was
not positive to say the least

216
00:10:21,580 --> 00:10:24,080
and you can confirm as much
yourself with a bit of Googling.

217
00:10:24,080 --> 00:10:26,630
And we responded quickly and decisively.

218
00:10:26,630 --> 00:10:29,630
And indeed, they have begun
to remove and provided users

219
00:10:29,630 --> 00:10:31,550
with instructions for
removing this software.

220
00:10:31,550 --> 00:10:34,610
And if you'd like to learn more
because you own a Lenovo laptop,

221
00:10:34,610 --> 00:10:38,480
do take a look at this URL here.

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00:10:38,480 --> 00:10:41,180
And now for something
a lot less stressful.

223
00:10:41,180 --> 00:10:45,500
Our good friend John Oliver recently
took a look at an amazing new product

224
00:10:45,500 --> 00:10:47,510
called a Salmon Cannon.

225
00:10:47,510 --> 00:10:49,700
And we thought we'd take a look.

226
00:10:49,700 --> 00:10:54,200
JOHN OLIVER: Salmon famously have to
fight their way upstream to spawn.

227
00:10:54,200 --> 00:10:57,410
But thanks to hydroelectric dams,
that's become increasingly difficult.

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00:10:57,410 --> 00:11:02,807
But don't worry, because as we found
out recently, America is on it.

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00:11:02,807 --> 00:11:04,640
BEN TRACY: I'm Ben Tracy
in Washington state

230
00:11:04,640 --> 00:11:08,060
where we're going to introduce you
to a pretty sweet piece of technology

231
00:11:08,060 --> 00:11:11,490
known as the Salmon Cannon.

232
00:11:11,490 --> 00:11:14,565
That's coming up on CBS this morning.

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00:11:14,565 --> 00:11:17,190
JOHN OLIVER: Let me tell you how
much I love the Salmon Cannon.

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00:11:17,190 --> 00:11:21,030
I love it so much, we made
our own cannon this week.

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00:11:21,030 --> 00:11:24,310
So this thing is pretty powerful.

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00:11:24,310 --> 00:11:26,970
So who wants to give this puppy a go?

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00:11:26,970 --> 00:11:30,295
Let's see where this salmon ends up.

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00:11:30,295 --> 00:11:33,420
SPEAKER 3: Of course, situation the
Mideast, only getting more complicated.

239
00:11:33,420 --> 00:11:34,753
The US has been bombing pretty--

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00:11:34,753 --> 00:11:36,450
[APPLAUSE]

241
00:11:36,450 --> 00:11:38,520
JOHN OLIVER: OK, OK.

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00:11:38,520 --> 00:11:40,950
So we know it works, we know it works.

243
00:11:40,950 --> 00:11:44,310
Let's try firing two
fish somewhere else.

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00:11:44,310 --> 00:11:45,870
JIMMY FALLON: Thank you spatulas--

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00:11:45,870 --> 00:11:46,740
oh, it's a fish.

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00:11:46,740 --> 00:11:50,065
[LAUGHTER AND APPLAUSE]

247
00:11:50,065 --> 00:11:53,870


248
00:11:53,870 --> 00:11:55,480
JOHN OLIVER: Very nice.

249
00:11:55,480 --> 00:11:58,760
Let's try something a
little more difficult.

250
00:11:58,760 --> 00:12:02,240
SPEAKER 4: Picture, And this
is what it looks like in--

251
00:12:02,240 --> 00:12:05,120
JOHN OLIVER: Clearly, this is the
greatest object that has ever been

252
00:12:05,120 --> 00:12:07,950
invented, so I am emptying this bucket.

253
00:12:07,950 --> 00:12:09,982
And let us see how big
we can go on this thing.

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00:12:09,982 --> 00:12:12,440
SPEAKER 5: Where we get started
with revealing of the crew,

255
00:12:12,440 --> 00:12:13,970
what we really want to do is we'll--

256
00:12:13,970 --> 00:12:17,393
[CHEERFUL MUSIC PLAYING]

257
00:12:17,393 --> 00:12:18,860


258
00:12:18,860 --> 00:12:20,780
SPEAKER 6: All right.

259
00:12:20,780 --> 00:12:24,140
SPEAKER 7: In this for loop, you're
going to want to direct them--

260
00:12:24,140 --> 00:12:25,700
DAVID MALAN: That's it for CS50 Live.

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00:12:25,700 --> 00:12:27,825
Thanks so much to the whole
team behind the camera,

262
00:12:27,825 --> 00:12:30,980
thanks so much to you for tuning in.

263
00:12:30,980 --> 00:12:33,830
This was CS50.

264
00:12:33,830 --> 00:12:41,080
[GUITAR MUSIC PLAYING]

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00:12:41,080 --> 00:12:54,251