18.2.1. Encryption and Decryption Algorithms

Try these first

1. 1.

   What is symmetric key encryption?

   Hint

   Think about the key used in both processes.

2. 2.

   Define plaintext.

   Hint

   What do we call the message before it is scrambled?

3. 3.

   What is symmetric key encryption?

   • Use of different keys for encryption and decryption
   • Use of same key for both encryption and decryption
   • No keys are used

   Hint

   Remember the definition shared in class.

4. 4.

   True or False: The Diffie-Hellman protocol can securely create a shared key even over insecure channels.

   • True
   • False

   Hint

   Consider the main purpose of the Diffie-Hellman protocol.

5. 5.

   Consider a scenario where Sita and Ram have established a symmetric key. If an adversary intercepts their ciphertext, what cryptographic strategies could they employ to attempt to recover the plaintext? Discuss the feasibility of these methods.

   Hint

   Reflect on how long cracking a strong key would take.

6. 6.

   The security of the Diffie-Hellman protocol relies on the difficulty of the discrete logarithm problem. How might changes in computational power influence its security? Discuss potential impacts on cryptographic practices.

   Hint

   Think about how advancements in technology can change encryption strengths.