Part 4: Explain in a couple of paragraphs how public key encryption can be used to implement a digital signature. Be sure you are very clear on when a private key is used and when a public key is used.

Part 5: Generally, a digital signature involves encrypting a cryptographic hash, or digest, generated from the message. Explain why we do not encrypt the message itself. You can answer this question in one sentence.

Part 6: For each of the following scenarios below, tell what type of encryption is most appropriate and in a sentence or two explain the reasoning for your choice.
1. Alice wants to send a confidential message to Bill, whom she has never met and who lives in a distant country.
2. Charlie wants to be sure that no one but he can see the financial and medical records he has stored on his computer.
3. David needs a way to check that large computer files stored on corporate servers have not been modified.
4. Eddard uses a "cloud" backup service; he wants to be sure the operators of the service cannot read his files.
5. Frank needs to send a message to George. The message need not be confidential, but George must be assured that it actually came from Frank.

Implementing Polynomials using Singly Linked List in C++

1. The Term Class
   
   Create a class to represent a term in an algebraic expression. As defined here, a term consists of an integer coefficient and a nonnegative integer exponent. E.g.
   
   • in the term 4X², the coefficient is 4 and the exponent 2
   • in -6X⁸, the coefficient is -6 and the exponent 8
   
   Your class will have a constructor that creates a Term object with a coefficient and exponent passed as parameters, and accessor methods that return the coefficient and the exponent
   
   
   II. The Polynomial Class
   
   Now create a class to represent a polynomial. As defined here, a polynomial is a sequence of terms. E.g.
   
   1. 3X² + 4X⁴ + X⁶
   2. 2 + 5X² + 6X³ + 2X⁷
   3. 4X¹⁰
   
   The terms of polynomial 1 are (3,2), (4,4) and (1,6). The terms of polynomial 2 are (2,0), (5,2), (6,3) and (2,7). Polynomial 3 has only one term (4,10)
   
   F To receive credit for this assignment, your class must use a generic “List of Term” to store the terms of a Polynomial object
   
   Your class will have a constructor that creates an empty list and additional methods to do each of the following:
   
   1. insert a new term in its proper place in a polynomial (see “Additional Specifications,” below)
   
   2. return all the terms of a polynomial as a single line string, as shown here:
   
   3x^2 + 4x^4 + x^6
   
   3. delete a term from a polynomial (see “Additional Specifications,” below)
   
   4. Compute and return the derivative of all the polynomial

5. reverse the order of the terms in a polynomial (see “Additional Specifications,” below)


III. The Test Class

The main method of your test class will create a Polynomial object and then read and process a series of operations

The operations are:

1. INSERT X Y

Insert a new term with coefficient X and exponent Y into its proper place in the polynomial

(insert method : adds terms to the list in descending order of power)

2. DELETE X Y

Remove the term with coefficient X and exponent Y from the polynomial

3. REVERSE

Reverse the order of the terms of the polynomial

4. 1^st DEV

          to find the first derivatives of the polynomial

   2^nd DEV

         to find the second derivatives of the polynomial

Each operation is to be carried out by calling a method of the Polynomial class

Each operation read must be “echo printed” to the screen

After each operation, print the updated polynomial by calling the toString() method

For the Derivatives operation, print the string returned
-----------------------------------------------------------------------------

DESIGN A FLOWCHART IN THE APPLICATION FLOWGORITHM

Number Analysis Program Design a program that asks the user to enter a maximum of 20 numbers. The program should store the numbers in an array and then display the following data: -The lowest number in the array. -The highest number in the array. -The total of the numbers in the array. -The average of the numbers in the array.

PLEASE AND THANK YOU

subject DBA

use mysql workbench and select my guitar shop database as default schema

Problem8

Write a script that implements the following design in a database named my_web_db:

    users                                                       downloads                                                                 Products

*user_id INT                                         * download_id INT                                                   * product_id INT                     

*email_address VARCHAR(100)          * user_id INT                                                         * product_name VARCHAR(45)

*first_name VARCHAR(45)                  *download_date DATETIME

*last_name VARCHAR(45)                  * filename VARCHAR(50)

                                                               *product_id INT

Details

• In the downloads table, the user_id and product_id columns are the foreign keys.
• Include a statement to drop the database if it already exists.
• Include statements to create and select the database.
• Include any indexes that you think are necessary.
• Specify the utf8 character set for all tables.
• Specify the InnoDB storage engine for all tables.

Solution fill in the blanks :-

______DATABASE ____________ ;

CREATE DATABASE my_web_db ___________ ;

USE my_web_db;

_________ TABLE _______

    user_id       INT          PRIMARY _______ AUTO_INCREMENT,

    email_address VARCHAR(100) UNIQUE,

    first_name    VARCHAR(45) NOT NULL,

    last_name     VARCHAR(45) NOT NULL

) ___________ ;

__________ products (

    product_id   INT         ________ AUTO_INCREMENT,

    product_name VARCHAR(45) UNIQUE

__________

____________

    download_id   INT         PRIMARY KEY,

    ____________       INT         NOT NULL,

    download_date DATETIME    NOT NULL,

    filename      __________ NOT NULL,

    product_id    INT         NOT NULL,

    ___________ fk_downloads_users

_____________ KEY (user_id )

        REFERENCES users (user_id),

_______________

_______________ product_id)

        REFERENCES products _______________

) ENGINE = _________ ;

what does this code means. Explain each line (briefly)

Book.findOneAndUpdate[{isbn:req.params.isbn},

{$set:{authFName:req .body.authFName,

authLName: req.body.authLName}, {new:true}}

Multiples of 2 and 3: write a c++ program Using a while loop, write a program that reads 10 integer numbers. The program shall count how many of them are multiples of 2, how many are multiples of 3, and how many are NOT multiples of either 2 or 3. The output should be similar to the one shown below.

In C++, please build a simple Distance Vector program that will communicate with N partners and do the following. (NOTE: All connections between a server and clients should be TCP/IP socket.)

1. You will run N instances on your machine
2. Each instance will run on a different port (instance 1 will run on port 18181, instance 2 on port 18182, instance 3 on port 18183, etc)
3. The program will start by reading in the appropriate neighbors file and vector file.
4. The program will ONLY read vectors where the fromNode is equal to that node. For instance, node 1 will only read in vectors where node1 is the fromNode.
5. The program will support the following requests from clients:
   1. Show files at the server’s current directory: ‘print’
      1. This will print the current vector table on a node.
      2. ONLY print valid vectors (don’t print uninitialized ones)
   2. Download files: ‘refresh’
      1. This will force the current node to send its vector table to all its neighbors.
   3. Upload files: ‘update’

1. This will be of the form: Update fromNode toNode cost
2. Update checks that the toNode is the current node. If it is not it is ignored
3. Update then checks if the toNode-fromNode exists in vector table. If it does not it is added and neighbors are notified
4. If the pair is in the table, and if the new cost is less than the old cost, that cost is stored and the neighbors are notified.

Discuss modern trends in local area networks?

2. Write python code for the below instructions (don’t forget to use the keyword “self” where appropriate in your code):

A. Define a Parent Class called Person

a. Inside your Person class, define new member variables called name, age, and gender.   Initialize these variables accordingly.

b. Define the constructor to take the following inputs: name, age, and gender.   Assign these inputs to member variables of the same name.

B. Define Child Class called Employee that inherits from the Person Class

a. Inside your Child class, define new member variables called title and salary.   Initialize these variables accordingly.

b. Define the constructor to take the following inputs: name, age, gender, title, and salary.   Assign these inputs to Class member variables of the same name. Note, you will need to specifically call the Parent constructor method inside the Child constructor, passing the appropriate inputs to the Parent constructor.

C. Instantiate an Employee object called George with the following inputs: name = “George”, age = 30, gender = “Male”, title = “Manager”, and salary = 50000.

D. Print out the object’s name, age, gender, title, and salary in one print statement to the console window. Your output should look like:

“George's info is: Name is George, Age is 30, Gender is Male, Title is Manager, and Salary is 50000”

Write a program that takes a string from the user, identifies and counts all unique characters in that given string. You are bound to use only built-in string functions where necessary. For identification of unique characters and for counting of the characters make separate functions.

For character identification

Develop a program that takes a string argument, and returns an array containing all unique characters.

For character counting

Develop a program that takes an array returned from above function as an argument along with the given string and return an array containing the total count of each uniquely identified character present in the argument array.

(Dev Cpp +Multifing )

If you have been involved in a situation in the workplace where a feasibility analysis was not done and should have been done and time or money (or worker sanity/happiness) was lost, tell us about it (you can change the names of the parties involved). Based on what you've read about decision filters do you think such a practice might have helped? Please remember to write at least 250 words on this topic.

Assume that the population of Mexico is 128 million and that the population increases 1.01 percent annually. Assume that the population of the United States is 323 million and that the population is reduced 0.15 percent annually. Write an application that displays the populations for the two countries every year until the population of Mexico exceeds that of the United States, and display The population of Mexico will exceed the U.S. population in X years.

the answer should look something like this: they want multiple answers. there is a pattern

322, 321, 320, 319, 318, 312, 311, 310, 300, 299, 298, 297, 296, 295, 288, 287, 286

Write a program that calculates and prints the bill for a cellular telephone company. The company offers two types of services: regular and premium. Its rates vary depending on the type of service. The rates are computed as follows:

Regular service: $10.00 plus the first 50 minutes are free. Charges for over 50 minutes are $0.20 per minute.

Premium Service:        $25.00 plus

in C++ (Basic)

1. For calls made from 6:00 A.M. to 6:00 P.M., the first 75 minutes are free; charges for over 75 minutes are $0.10 per minute.
2. For calls made from 6:00 P.M. to 6:00 A.M., the first 100 minutes are free; charges for over 100 minutes are $0.05 per minute.

Your program should output the type of service, number of minutes the telephone service was used, and the amount due from the user.

For the premium service, the customer may be using the service during the day and night. Therefore, to calculate the bill, you must ask the user to input the number of minutes the service was used during the day and the number of minutes the service used during the night.

A state is divided into R*C cities.The government has launched an initiative to find the cities which are dominated by coders. Each city may or may not have coders residing in it. If the city is dominated by coders, it is marked with 1 else it is marked with 0. Two cities are termed as connected cities if they both are dominated by coders and can be reached by moving vertically, horizontally, or diagonally.

Example:

The given is the state with 3*3 cities and their dominance representation.

City[1, 1] is directly connected to City[1, 2].

City[1, 2] is directly connected to City[1, 1], City[1, 3] and City[2, 3].

City[1, 3] is directly connected to City[1, 2] and City[2, 3].

City[2, 3] is directly connected to City[1, 2] and City[1, 3].

City[3, 1] is not connected to any of the other coder dominant cities.

One or more coder dominant connected cities form the Coding belt. In a belt, there may be coder dominant cities which are not directly connected but can be reached by moving through other dominant cities. It is possible that there are multiple coding belts in the state.

Example:

The given is the state with 3*3 cities and their dominance representation.

For the given example, there are two coding belts. C1 represents Coding Belt 1 and C2 represents Coding Belt 2.

The government wants to find the number of coder dominant cities in the largest coding belt.

The government will give you the credits in the initiative. Can you help the government?

Note: For the given example, there are 4 coder dominant cities in the largest coding belt.

Input Format

The first line of input consists of two space-separated integers, number of rows, R, and number of columns, C.

Next R lines each consist of C space-separated integers.

Constraints

1<= R, C <=10

Output Format

Print the number of coder dominant cities in the largest Coding belt.

Sample TestCase 1

Input

5 51 1 1 0 00 1 1 0 00 0 0 0 11 0 0 1 11 1 0 0 1

Output

5

Explanation

There are three belts in the given 5*5 cities.

Coding Belt 1 (C1): Number of Coder Dominant Cities = 5

Coding Belt 2 (C2): Number of Coder Dominant Cities = 4

Coding Belt 3 (C3): Number of Coder Dominant Cities = 3