Discuss how the asymmetric encryption algorithm can be used to achieve the following goals.
a. authentication: the receiver knows that only the sender could have generated the message.
b. secrecy: only the receiver can decrypt the message.
c. authentication and secrecy: only the receiver can decrypt the message, and the receiver knows that only the sender cosssuld have generated the message.

Write a program that prompts the user to input a string. the program then uses the function substr to remove all the vowels from the string. for example, if str = "there", then after removing all the vowels, str = "thr". after removing all the vowels, output the string. your program must contain a function to remove all the vowels and a function to determine whether a character is a vowel.

Assume the existence of a bankaccount class. define a derived class, savingsaccount that contains two instance variables: the first a double, named interestrate, and the second an integer named interesttype. the value of the interesttype variable can be 1 for simple interest and 2 for compound interest. there is also a constructor that accepts two parameters: a double that is used to initialize the interestrate variable, and a string that you may assume will contain either "simple", or "compound", and which should be used to initialize the interesttype variable appropriately. there should also be a pair of functions getinterestrate and getinteresttype that return the values of the corresponding data members (as double and int respectively).

In a word processing program, such as microsoft word, which feature to you choose the desired picture enhancement?