$1.$ We discussed how cryptographic techniques can be used to communicate while preserving the principles of$$confidentiality$,$integrity$,$authentication$,$ and$$non$-$repudiation.

Suppose Alice and Bob want to communicate securely$,$ while Eve $($the eavesdropper$)$ wants to steal and$/$or sabotage Alice and Bob's communications.$$ For each of the four $(4)$ principles listed above, describe a way that Alice and Bob can thwart Eve's plans $($i$.$e$.,$ how can Alice and Bob use cryptographic techniques for confidentiality, integrity, authentication, and non$-$repudiation$).$ Explain clearly how the techniques preserves the claimed principle.$$If you propose a technique that address multiple principles, explain clearly what part of the technique addresses which principle.$$

$2.$ One of the conditions of using hashing for digital signatures is that we must avoid collisions $($both weak and strong$).$ Explain why it is important to avoid collisions.$$ Provide an example of a way an attacker could exploit a hash collision.$$ Refer to which of the principles of confidentiality, integrity, authentication, and non$-$repudiation could be compromised.$$

Note:

You should be able to answer both of these questions based solely on the materials we discussed in class.$$If you rely on an external source, you must cite it$.$

Responses should depend on$$critical thinking$$and$$include an explanation of your reasoning.