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General purpose data (files, messages, webpages, etc.) should be encrypted / decrypted in  mode HINT: Provide the full name

See the previous question.  Describe in words the inverse of the operation performed above.  

Suppose that someone in your neighborhood is monitoring your Wi-Fi. The payload of every data packet is encrypted, so that person cannot read your data.  They notice that every time you send several packets to a certain IP address, one or more packages from Amazon are delivered the next day.  The next time you interact with that website, they watch your porch and steal some packages.    That person’s process of monitoring your Wi-Fi and concluding it is related to Amazon deliveries is best categorized as …  

Suppose you browse to a website that presents a typical X.509 certificate chain, containing three (3) certificates.  The certificate at the bottom of the chain is for the website.  You browser shows that the certificate is verified.  Which of the following is/are true about the certificate at the top of the chain?  

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.  

General purpose data (files, messages, webpages, etc.) should be encrypted / decrypted in  mode.   Give the complete name, not an abbreviation.  

See the previous question.  Explain in words how you could efficiently determine the value of C XOR B, if you have already calculated A XOR B as above.  

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

C = 98765432D = 23456789Calculate (C x D) mod 10 as efficiently as possible. Show your calculations. HINT:  Use the modular multiplication property.  

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.