Mod 11 - Security & Privacy Flashcards
Why is encryption important?
When you send a message, it’s like a postcard because any device between the sending location and destination can look at the information (packets) you sent. So, anyone, including “evil doers”, can copy your message and save it meaning encryption is important for maintaining security and privacy.
What is Caesar cypher?
It takes the alphabet and and shifts all the letters a certain number away. (Ex. +3 means a -> d, b ->e, etc). If the receiver knows the number and method, then they can decrypt your message so it stays private. in modern technology, it is similar, but much larger numbers are used.
What is a one way function?
It is easy to do in one direction but not the other (ex. cracking an egg is easy to do but hard to undo).
How does modulo work?
It refers to the remainders and is what computers use. For example, 1337/10=133.7 so our remainder is 7. In modulo, this equation is written as 1337 mod 10 = 7. Computers use more advanced versions (ex. 3^x mod 17) so no one can intercept the messages.
What are asymmetric keys?
It is a 2 key lock system. The blue (public) key can turn the lock clockwise while the red (private) key can turn the lock counterclockwise. This means you can use the blue key to send a message but only the red key can unlock it. Once you both have the information, you can use a green key to continually send messages back and forth.
How do we verify you send the information and not an imposter?
Third parties are used to verify people so we know they can be trusted and they are who they say they are.
How does HTTPS work?
If you want to do something secure on the internet, you communicate with “https://website.com” and say you can do protocol X, Y or Z. This message is sent to a server, where protocol X works, so it sends back a public key and a certificate (verified through 3rd party). You send a message back to the server so you get a shared key to communicate privately now.
What is used on messages to avoid forgery?
Each message has its own time stamp and certificate to ensure you are still communicating with the right person.
