Encryption (1.3.1 c)

Question 1

Encryption

Answer 1

used to secure the data during transaction
the sender encrypts the data this creates the cipher text
the receiver decrypts the data this then retrieved the plain text
the files are encrypted and decrypted with keys
the cipher key is designed to be meaningless to anyone without the key

Question 2

Historical encryption methods

Answer 2

caeser cipher
every letter is sifted by a given value (key)
e.g a key of 5 turns A=F B=G etc
random substitution cipher
every letter is randomly swapped with another
the key is the tab;e showing what each letter matches with

Question 3

Symmetric encryption

Answer 3

encryption and decryption are done with the same key
sharing secrets reliably and at scale is very difficult
best for stored data as keys can’t be shared safely

Question 4

Asymmetric encryption

Answer 4

a different key is used to encrypt and decrypt
major method to do this is public cryptography
private and public key
private key can never be shared
public key can be shared freely
private/public key are mathematically linked
public key encryption can only be decrypted by private key
private key encryption can only be decrypted by public key

Question 5

Asymmetic encryption example

Answer 5