John recently received an email message from Bill. What cryptographic goal would need to be met to convince John that Bill was actually the sender of the message?Group of answer choicesConfidentialityAvailabilityNonrepudiationIntegrity

Which of the following cryptographic objectives can guarantee that the sender of a message cannot later deny having sent the message and that the recipient cannot deny having received the message?Group of answer choicesConfidentialityNonrepudiationIntegrityAuthentication

Joseph and Shawn work as security analysts at XYZ. Joseph sends an email to Shawn regarding a deal with a client. After some days, Joseph denies that he had ever sent an email. Which of the following should Shawn know to prove that it was Joseph who had sent an email?This type of question contains radio buttons and checkboxes for selection of options. Use Tab for navigation and Enter or space to select the option.optionAIntegrityoptionBNonrepudiationoptionCAvailabilityoptionDConfidentiality

________ is the ability to ensure that messages and data are only available to those authorized to view them.Group of answer choicesAvailabilityConfidentialityIntegrityPrivacy

________ is the ability to ensure that messages and data are only available to those authorized to view them.Group of answer choicesPrivacyIntegrityConfidentialityAvailability

The consortium are interested in implementing signatures into the crypto-system. The goal is to provide an authentication mechanism which allows a recipient to see from whom the message originated. The consortium leader considers several options for how to implement this mechanism. State whether or not each option is secure, and provide a justification. Suppose Aldebaran wishes to send a message to Borealis, and Aldebaran possesses a signing keypair (sk′A, pk′A). (Hint: think about what eavesdroppers can learn about the identities of senders) Aldebaran computes σ = Sign(sk′A, m), and cσ =Enc(pkC, σ).Aldebaran sends this ciphertext along with their usual broadcast(pkC, cdest, cmsg). Chandra performs her usual steps, as well as decrypting to obtain σ =Dec(skC, cσ). She sends it along with her usual broadcast (pkB, c′msg) for Borealis. Lastly, Borealis, decrypts to obtain the message m. Borealis believes the message should have come from Aldebaran. He runs Verify(pk′A, m, σ) and is satisfied only if the signature accepts.