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

Differences between internal and external fragmentation, Explain the differ...

Explain the differences between Internal and external fragmentation. Internal and external fragmentation (1) While memory allocated to a process is a little larger than th

Directory of the distribution, I tried to run two of the applets in the exa...

I tried to run two of the applets in the examples directory of the distribution?    Ans) I tried to run two of the applets in the example directory of the distribution. I instal

What are the main features of uml, What are the main features of UML ...

What are the main features of UML Defined system structure for the object modelling Support for all different model organization Strong modelling for behaviour an

Kruskal''s, Image Segmentation with Minimum Spanning Forests (50 points). D...

Image Segmentation with Minimum Spanning Forests (50 points). Develop a Python 3 implementation of the image segmentation algorithm that we explored on the first day of class. Your

more data items and methods, Create a class called ticket that records the...

Create a class called ticket that records the information of a performance ticket.The class should include at least six data items: performanceId, seatRow, seatNo, class, price, da

Explain a binary semaphore, Explain a binary semaphore with the help of an ...

Explain a binary semaphore with the help of an example? An abstract data type (ADT) is a semaphore which defines a nonnegative integer variable that apart from initialization i

Define public identifiers, Q. Define Public Identifiers? Public Identif...

Q. Define Public Identifiers? Public Identifiers: A public identifier is one which is defined within one module of a program however potentially accessible by all of the other

What is the difference between vb6 and vb.net, What is the difference betwe...

What is the difference between VB6 and VB.Net? 1,Object-based Language 2,Doesnot support Threading 3 Not powerful Exception handling mechanism 4,Does not having suppor

The types of parameters in the function modules, What are the types of para...

What are the types of parameters in the function modules? In general, function module can have four types of parameters: EXPORTING : for passing data to the called function

Explain bootp (boot strap protocol), Explain BOOTP (Boot Strap Protocol). ...

Explain BOOTP (Boot Strap Protocol). TCP or IP designer observed that several of the configuration steps could be combined in a single step if a server was capable to supply mo

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