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Cryptography: substitution-permutation network

Consider the following 2x2 s-box x | S(x) ---|------- 0 | 3 1 | 1 2 | 0 3 | 2 Consider 2-round SPN (substitution-permutation network) with a block length of 4 bits. If the key mixing is done using a mod-4 addition operation before each round and after the last round, determine the ciphertext corres

VLookup and Excel

Use the VLOOKUP function in the formula to determine gallons per hour based on the type of plane, then multiply the result by the number of flying hours to compute the amout of fuel for each flight. The table for VLOOKUP function extends over three columns. Use the fuel required from part (a) to compute the additonal requirem

(ref2) Integer Range for one byte word in various representation.

A given microprocessor has words of one byte. What is the smallest and largest integer that can be represented in the following representations? a. Unsigned b. Sign-magnitude c. Ones complement d. Twos complement e Unsigned packed decimal f. Signed packed decimal

Top Down, Stepwise refinement

Using top-down, stepwise refinement, create an algorithm for making toast, frying eggs, baking a cake, or ordering pizza. How might algorithms be beneficial in your future profession?

(ref7) Binary Sign Magniture

A. Convert +512 into sign/magnitude. b. Convert -29 into sign/magnitude. c. Convert +512 into two's complement. d. Convert -29 into two's complement.


2. The problem with symmetric cryptosystems is distribution of keys. How do the public key algorithms solve this problem?

Bit representation

5. Extra Points: How many bits are needed to represent a number that is 100 decimal digits long? How many decimal digits are needed to represent a number that is 1000 bits long? How many decimal digits are needed to represent a number that is 100 decimal digits long?

CLS on heads or tails program

I also need to fill in the missing part of the code In MS-DOS, the command to clear the screen is cls; in UNIX, it is clear. Try the command so that you understand its effect. Modify the heads_or_tails program so that the screen is cleared at the beginning of the program. Use the function call system ("cls") or system ("clear")


Please help me performing a quick ERD diagram design from this employee tracking model.

ERD Design

For this customer sales order systems, perform an ERD design for this(fully-attribued, key_based ERD up to 3rd NF)--from the attached file.

Algorithms - Design and Analysis Fundamentals

A. Design a recursive algorithm whose input is a decimal integer and whose output is the binary representation of the input. b. Design a recursive algorithm that computes the reverse of the result in (a) - that is, converts a binary integer to its decimal equivalent.


Trace the action of the algorithm BabylonianSQRT for the following input values of a and error = 0.001: a. a = 6 b. a = 23 c. a = 16


Show that computing x15 by either the right-to-left binary method or the left-to-right binary method requires six multiplications, and demonstrate that it can be done using only five multiplications.

Rows in a Query

If you had two tables, each with 3 items: Table_Mike: ITEM: Bread Milk Eggs Table_Kristy: ITEM: Cereal Butter Eggs And performed a UNION, how many rows would the resulting query have?

A N*N magic matrix where N is odd

Magic matrix A N*N matrix is called a magic matrix if it is filled with numbers in {1.. N^2} and sum of the values in all rows, columns are equal. Supposing an odd N, we are planing to describe how to create such a matrix. Example of such a matrix is as following:


Probabilities 1.) A taxicab was involved in a fatal hit-and-run accident at night. Two cab companies, The Green and The Blue, operate in the city. You are told that: ? 85% of the cabs in the city are Green and 15% are Blue ? A witness identified the cab as Blue The court tested the reliability of the witness under the same c

Dijkstra?s Shortest Path Algorithm

Consider the following network. a) With the indicated link costs, use Dijkstra?s shortest path algorithm to compute the shortest path from E to all network nodes. Show how the algorithm works by computing a table. b) Eliminate node A, and redo the problem starting from node B. Please refer to the attachment to view the

Please explain VAL(MID$(i$, i, j))

Point 5: Please explain VAL(MID$(i$, i, j)) Point 4: If I am going backwards down the string, then how do I pick up all the substrings since the string is read left to right? This is in the context of the following solution: 1 i$ = "37540" 'input string 2 FOR i = 1 TO LEN(i$) 'loop from 1 to the length of the input