Cryptography, Computer Engineering

Assignment Help:

Basically I need implement program using LC3 assembly language where I can type any message using ASCII code (this will my input). Then read the output in cipher text. It has to be a combination of this to labs in the bottom. ( please make sure design the flow chart for the program)

Computer Organization and Architecture Lab 4: Cryptography

Description:

An encryption algorithm transforms "plain text" into "cipher text." Just like a door needs a key to lock and unlock it, an encryption algorithm often requires a key to encrypt and decrypt a message. For example, suppose the plain text message is HELLO WORLD. An encryption algorithm consisting of nothing more than replacing each letter with the next letter in the alphabet would produce the cipher text IFMMP XPSME. The decryption algorithm simply replaces each letter with the one before it, and presto: the plain text HELLO WORLD is produced.
Procedure:

Implement, in LC-3 assembly language, an encryption/decryption program that meets the following requirements:
1. The key is 6 and stored at x31 00.
2. Your message is restricted to a maximum of 32 characters. They are stored at x3110 to x311 F. The last ASCII code of the text string must be EOT (x04).
3. The encryption algorithm is as follows. Each ASCII code in the message will be transformed as follows:
• The low order bit (LSB) of the code will be toggled. That is, if it is a 1, it will be replaced by 0 and vice verse.
• The key will be added to the result of step 1 above.
• The result should be stored at location x3120 to x312F.
• For example, if the input (plain text) is A and the encryption key is 6, the program should take the ASCII value of A, 01000001, toggle bit [3:0], producing 01001110 and then add the encryption key, 6. The final output character would be 01000110, which is the ASCII value F.
4. Decryption algorithm is as follows. Each ASCII code in the message will be transformed as follows:
• Subtract the encryption key from the ASCII code.
• Toggle the low order bit of the result of ste

• The result should be stored back to location x311 0 to x311 F.
Notes and Suggestions:
• The first line of your programs must specify the memory address of the first instruction of your program. LC-3 simulator will place your program starting at that address. For this assignment, you should place your program starting at x3000 (using the .ORIG pseudo¬op) .
• If you are using a Windows machine, use the LC3Edit program to type in your programs.
On Sun and Linux workstations, pico, emacs, and vi are several of the text editors you can use. Your program file needs to be in plain text format.


Related Discussions:- Cryptography

Advantages to companies adopting call centres, Advantages to companies adop...

Advantages to companies adopting call centres Computer systems have allowed companies to set up call centres in other nations where potential cost savings can be made. This, of

Why we need the need of parallel computation, THE NEED OF PARALLEL COMPUTAT...

THE NEED OF PARALLEL COMPUTATION   With the growth of computer science, computational pace of the processors has also increased many a times. Though, there are definite constr

Explain approaches to reuse free memory area in a heap, Discuss two main ap...

Discuss two main approaches to reuse free memory area in a heap. Two major approaches to reuse free memory area in a heap are: First-fit: Allocate the first hole which i

Mention the two subsystem relationship, Mention the two subsystem relations...

Mention the two subsystem relationship. The relationship among two subsystems can be: Client-server Peer-peer

Explain metadata, What is metadata? Metadata is data that explains anot...

What is metadata? Metadata is data that explains another data. Class definition is metadata. Models are inherently metadata as they explain the things being modeled.

Explain host function, Explain Host function Host function: accepts nam...

Explain Host function Host function: accepts name of floating-point guest function with single floating-point argument as its first argument, evaluates this function at x (the

How to call a wml script from a wml page, WML & WML Script 1. How to ca...

WML & WML Script 1. How to call a WML Script from a WML Page? 2. Write a brief note on WML Script Operators and Expressions. 3. Write brief notes on WML Script Statements

Prints the hundreds digit in two integers , Write an application that prin...

Write an application that prints the hundreds digit  in two integers read from the keyboard. For example if the data values are 1456 and 255 respectably, output should include the

DoDAF OV-2 for a green datacenter, How do I create a DoDAF OV-2 for the con...

How do I create a DoDAF OV-2 for the construction of a green data center?

Define a B- tree of order m, Define a B tree of order m. B Tree of orde...

Define a B tree of order m. B Tree of order m  A balanced multiway search tree of order m in which every non root node having at least m/2 keys is known as a B-Tree of order

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd