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

Abap/4 dictionary structures without an underlying database, It is not poss...

It is not possible to use ABAP/4 Dictionary Structures without an underlying database using LDB. True.  You can use additionally related tables, along with the tables explaine

Which device converts BCD to seven segment, A device which converts BCD to ...

A device which converts BCD to Seven Segment is called ? Ans. DECODER is a device that converts BCD to Seven Segment. This coverts binary words in alphanumeric characters.

Estate agency application, Build U Like are a building company specialising...

Build U Like are a building company specialising in hard landscaping. They lay patios, build walls, lay drives etc. for their customers. A customer will remain in the system even t

Explain the edge-triggered j-k flip-flop, Explain the Edge-triggered J-K fl...

Explain the Edge-triggered J-K flip-flop? The J-K flip-flop works extremely similar to S-R flip-flop. The merely difference is that this flip-flop has NO invalid state.

Engineering and managerial economics, write a short note on good blend of e...

write a short note on good blend of engineering and managerial economics

Career after BSc CS, Sir,wish to receive guidance from you how to join in A...

Sir,wish to receive guidance from you how to join in Aeronautical Engineering after Bsc Computer Science. I am a Girl.Interested to work in AE field, it will be better to use in co

What are the touch panels, What are the Touch Panels In case of touch p...

What are the Touch Panels In case of touch panels, displayed objects or screen positions is allowed to be selected with the touch of a finger. A typical application of touch pa

State the selective clear - logic micro operations, State the SELECTIVE CLE...

State the SELECTIVE CLEAR - logic micro operations The selective-clear operation clears to 0 bits in register A only  where there are corresponding 1's in the register B. For

Boolean algebra, Boolean algebra. Boolean algebra mathematical method ...

Boolean algebra. Boolean algebra mathematical method based on human reasoning. In Boolean algebra only two states exist; true and false which are written as 1 (true) and 0 (fa

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