11.5 In a study involving the villagers, the researchers offered the king an amount of R10, 000 whilst seeking permission to conduct the study in the area

See the previous question. Bob forwards the message and the digital signature to Zoe.  Can Zoe read the message?  Can Zoe verify the digital signature? 

See the previous question. Explain what Charlie would attempt to do to perform this type of attack.  Your answer must be specific to the scenario described. 

A digital signature enables non‑repudiation.  Explain what this means for Alice and Bob if Bob successfully verifies a digital signature that accompanied a message from Alice. 

An organization has a large amount of ciphertext that was encrypted long ago using DES.  The organization is now using the Triple DES Encryption Algorithm (TDEA). An employee has access to some DES ciphertext and the key used to encrypt it.  What is the best way for the employee to decrypt this ciphertext?

Alice sends a message to Bob, along with a digital signature for the message.  Which key did Alice use to generate this digital signature?

The input to a simple encryption algorithm is a block of eight (8) bits, which we can represent as ABCDEFGH.  The result of a circular shift of 3 positions to the right on this data block can be represented as . 

The effective size of a key in the Data Encryption Standard (DES) algorithm is 56 bits. Explain in words how to calculate the size of the DES keyspace. 

A scheme developed by Whit Diffie, Martin Hellman, and Ralph Merkle is commonly called “Diffie‑Hellman”. What does this scheme directly enable? 

Suppose that a hacker is able to log into the administrative account for a webserver and change the configuration so that it does not accept incoming connections.  The hacker’s actions are an attack on the of the webserver.  Hint: The answer is the name of a cybersecurity service.