Cryptography

Question 1

How are cryptography and complexity theory related?

Answer 1

-complexity-theory figures out which problems are infeasible to compute, cryptography uses these infeasible problems for security

Question 2

two types of encryption?

Answer 2

-key
-shift, caesar cipher

Question 3

For the public key, which key is used to encrypt?

Answer 3

encrypt: public key
decrypt: Private key
RSA algorithm

Question 4

What are common bit sizes of keys, and why are the sizes important?

Answer 4

-size determines security
-128, 256, 512
*128 means 2128 different combos to find right key

Question 5

Caesar?

Answer 5

-substitute letters
-easy to attack (25 keys possible)

Question 6

Which key encodes signatuure?

Answer 6

Encode: private
Decode: Public

Question 7

What does it mean when protocol has s in name (Https vs http)?

Answer 7

encrypted network traffic

Question 8

Does the encrypted text have to be decrypted to be useful?

Answer 8

No (passwords)

Question 9

Plain text to cyber text:

Answer 9

encryption