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Course: NOVA Labs > Unit 1
Lesson 2: CybersecurityCyber codes
Do you trust the security of your email, text messages, and browser history? Learn how trustworthy online communication actually is and how encryption can protect your privacy. Sometimes.
Want to join the conversation?
- What is the highest level of encryption?(19 votes)
- If you encryption key is longer than your message you are very safe. un-breakable safe.
https://en.wikipedia.org/wiki/One-time_pad
But this technique is very cumbersome to use, especially over the internet.
So we use the public-key type that he explained in the video. you can make this key as long as you want, making it very safe. But maybe the method we use to make the public-key is flawed, and if it is it can be cracked.(0 votes)
- How are emails be intercepted in the first place?(4 votes)
- Emails can be intercepted using a network sniffer like Wire Shark.(6 votes)
- isn't coding and encrypting different? in the cryptography section there's a video discussing the difference between codes and ciphers , i am confused now(3 votes)
- why isn't PBS.org showing http?(1 vote)
- Will there ever be a time period where hacking and stealing ones information will no longer be a concern? Is computer scientists coming up with better way to encrypt technology including emails etc?(0 votes)
- A way for now is 1 megabyte encryption, as you would take 2.567 googolplexplex centuries to figure it out, but it's usually a space waste. So to be the ultimatum of cybersecurity of today, take 1 MB encryption.(3 votes)
- how do you make your secret key(1 vote)
- They are already made, you don't make them yourself.(1 vote)
- What level of encryption do we normally use today?(1 vote)
- At2:25what type of text messages are encrypted?(1 vote)
- Hard to tell. Use WhatsApp instead of, for example, imessage, because WhatsApp is 100% all the time encrypted.(1 vote)
- What is the difference between a secure and unsecured Wifi network? Can a Wifi router encrypt traffic?(1 vote)
- Not really. A secure Wi-Fi network will require a password in order to join, whereas unsecured networks don't require a password, and anyone, including hackers/eavesdroppers, can join and possibly intercept your messages.(1 vote)
- How does a system know the code you are given isn't being used anywhere else? For example, if i was given a certain code how does they system know not to give that same code to someone else?(1 vote)
Video transcript
When was the last time you sent a coded message? Well, probably within the last hour, if you’ve
sent an email or logged onto a website. We use codes all the time because we communicate
our private messages in public. Without codes, sending information online
over unsecured networks or networks with security holes would be like standing in Times Square
and shouting your innermost secrets at the top of your lungs, in a crowd of millions
of people doing the exact same thing. So to protect your privacy, you have to send
your messages as codes that can be read by your friends, but not by your enemies. Codes have played a critical role in just
about every major war in recorded history. In ancient Rome, Caesar used a simple code
to send messages to his generals. Two thousand years later, Allied code breakers
saved millions of lives and shortened World War II by cracking the German Enigma code. But codes aren’t just for emperors and soldiers;
today we use them to shop online and say hi to our friends. Let’s say you want to share a secret with
a friend. Here’s what happens after you hit send on
an encrypted email. First, your email services need to agree on
a secret key—a very large number—that will be used to lock and then unlock your
message. But they can’t just send that number over
the internet—an eavesdropper could intercept it. So they use a brilliant trick called public
key cryptography. Both sides start with a publicly available
number, but then add a dash of their own secret numbers and mix them together using mathematical
operations that are extremely difficult to reverse. They swap bowls and do it again—dash of
secret number, mix it up, and bam! Secret key. They used the same recipe, but never shared
their individual secret ingredients, so the key is safe. Now your email service uses that secret key
to transform and scramble your message. It transmits the coded message to your friend’s
email service, which uses the secret key to reverse the scrambles and transformations
and reveal the original text. Phew. That’s a lot of work for one email, but
it happens in the blink of an eye and without any effort on your part. The scary thing is, not all traffic is encrypted. Online payments usually are, but browser history
is not, nor are many text messages. Emails are complicated—they’re usually
encrypted when they’re sent, but are sometimes decrypted before they get to their recipient. Some websites encrypt their traffic; you can
tell by looking for the lock symbol in a URL. If it’s not there, anything you type into
that website can be intercepted. That’s one of the reasons it is so important
to have a different password for every website you visit and to avoid unsecure public Wi-Fi—where
your messages can be easily intercepted. The other problem is: almost every code in
history has been cracked in a way that initially seemed impossible. It could be the case that there is a chink
in the armor of the codes we use that no one has discovered yet. Or perhaps someone has, and is keeping that
information to themselves. So the next time you metaphorically shout
your innermost secret in public, take a moment to consider whether you’ve locked it up
tight enough—and what could happen if it got out.