18.1. Key Agreement and Secure Communication

Try these first

1. 1.

   What does encryption do?

   Hint

   Think about communication security.

2. 2.

   What is a shared key?

   Hint

   Remember the box analogy where both parties have the same key.

3. 3.

   What is the purpose of encryption?

   • To convert plaintext into ciphertext
   • To send messages
   • To unlock boxes

   Hint

   Think about how messages are secured.

4. 4.

   True or False: In symmetric encryption, different keys are used for encryption and decryption.

   • True
   • False

   Hint

   Recall the definition of symmetric encryption.

5. 5.

   If Sita and Ram both choose secret values and agree upon a common integer representation of these, describe the process they take without revealing their secrets. What security aspects are at play?

   Hint

   Think about how shared operations help lead back to a secret.

6. 6.

   Propose a scenario where an attacker might attempt to intercept the key agreement process. What strategies could Sita and Ram use to maintain their privacy effectively?

   Hint

   Consider preventive measures in secure communications.