The One-Time Pad is a symmetric cipher that offers perfect secrecy. If used correctly, there are no possible attacks to determine any information about the message from the ciphertext. Despite this, the One-Time Pad is very rarely used. Why do you believe this is?

3. Encipher the message 'cryptography’ using a Shift Cipher with k = 10. Show your work.

Research the modern usage of the RSA cipher; what is thecurrent key strength and why does it change periodically? How isthe current key length determined?

Computer Science Explain how the adversary can modify a ciphertext generated using a block cipher (e.g., AES) in CBC mode in such a way that the change in the cor-responding message is small and easily predictable for the adversary. (The adversary has no access to the decryption key.)