Opportunities

How is ENCRYPTION currently applied to address an opportunity?

How is encryption applied to address a password storage opportunity

Storing passwords
- One-way encryption
- Example: hashing - solution to attacks

How encryption is applied to address an internet communication opportunity ...

100 years ago encryption was mainly used by spies or the military. Today we do most of our communication and business online. The substitution systems described above don't provide enough security for modern digital systems.

One way in which we use encryption is when we are communicating with a secure website. Think about your privacy. In which of the situations below would you want your communication to be encrypted? (see table)

As a rule of thumb you can expect a website to be encrypted if you need to enter information into it, or if it lets you access private information that an organisation stores about you.

The internet is not private

When we send or receive data over the internet, it travels as binary data via a circuitous route.

The How Stuff Works website describes it simply as:

Data travels across the internet in packets. Each packet can carry a maximum of 1,500 bytes. Around these packets is a wrapper with a header and a footer. The information contained in the wrapper tells computers what kind of data is in the packet, how it fits together with other data, where the data came from and the data's final destination.

When you send an e-mail to someone, the message breaks up into packets that travel across the network. Different packets from the same message don't have to follow the same path. That's part of what makes the Internet so robust and fast. Packets will travel from one machine to another until they reach their destination. As the packets arrive, the computer receiving the data assembles the packets like a puzzle, recreating the message.

How encryption is applied to address an steganography opportunity ...

Steganography

Historically, one way to share a key is ‘hidden in plain sight’ - give a key to someone in a way that others aren’t expecting, so they don’t notice it. This is called steganography - the word combines the Greek words steganos (στεγανός), meaning "concealed", and graphein (γράφειν) meaning "writing".

Intro to steganography - https://www.youtube.com/watch?v=_8wAUdKF9Yk

Historical steganography examples:

Messages written in Morse code on yarn and then knitted into a piece of clothing worn by a courier.
Messages written on envelopes in the area covered by postage stamps.
During and after World War II, espionage agents used photographically-produced microdots to send information back and forth. Microdots were typically tiny (less than the size of a full stop).

microdot

Pictures embedded in video material, only visible when played at slower speed.
Making text the same color as the background in word processor documents, e-mails, and forum posts.

Nowadays we can hide code in digital items. An example of this is in images. The last two digits of the binary colour code make very little difference to the final colour. Can you tell the difference between these two colours? Notice that only the last two bits of each colour’s code have changed.

If this was a pixel in an image, and a few bits from each image were hijacked in this way, some binary code could be hidden in the image file.

Watch:

Secrets hidden in images - https://www.youtube.com/watch?v=TWEXCYQKyDc (first 5 mins only)

Activity: Current uses of stenography

Can you find any current uses of stenography? You could explore digital watermarking.

In summary: Steganography differs from cryptography in that users or viewers don’t necessarily know that there is a hidden message. In cryptography the message is changed and the changed version is sent, whilst in steganography the original image/video/sound file is sent, but with a second message hidden in it.

How could ENCRYPTION be applied to address an opportunity?

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