Part 1

Please write a function/method to implement a stream cipher algorithm which takes three inputs

1- The message to encrypt (A string)

2- The key (A string)

3- The algorithm (A string that is one of these: OR, AND, XOR)

Constraints

1- The key can not be bigger than the message string.

2- If the key is smaller than the message, the key should be repeated to match the size of message.

Example:

Message = 10101010011110010 Key = 1100

10101010011110010 - Message

11001100110011001 - Key with the size adjusted to the message.

3 - The function should not accept an algorithm other than OR, AND, XOR. If tried, it should give the message "Unknown algorithm"

Function

1 - Convert message and the key into binary form.

2 - Apply the given operation on the input and the key.

3 - Convert the resulted output into String

Part 2

1 - Explain the advantages and disadvantages of block and stream ciphers in a paragraph

2 - Explain the advantages and disadvantages of synchronous and asynchronous ciphers in a paragraph