This system uses two keys per user. Only one key is distributed so that there are n keys for n users. It provides encryption and digital signatures. Group of answer choices Caesar Cipher Cryptography Hash Function Symetric Key Cryptography Public Key Cryptography

Corey set up his presentation for delivery to his team.the information he had to convey was critical to their job performance.he knew he would need a lot of time to explain each point

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?

Perform the following tasks: a. create a class named testclass that holds a single private integer field and a public constructor. the only statement in the constructor is one that displays the message “constructing”. write a main()function that instantiates one object of the testclass. save the file as testclass.cpp in the chapter 08 folder. run the program and observe the results. b. write another main()function that instantiates an array of 10 testclass objects. save the file as test class array.c . run this program and observe the results.