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

Define master construct in fortan, Q. Define Master Construct in FORTAN? ...

Q. Define Master Construct in FORTAN? The master directive has following general form:  #pragma omp master structured_block  It causes master thread to execute structu

Give the difference b/w multiprogramming and multiprocessing, Give the diff...

Give the difference between multiprogramming and multiprocessing. A multiprocessing system is a computer hardware configuration which contains more than one independent proc

What is sector sparing, What is sector sparing? Low-level formatting al...

What is sector sparing? Low-level formatting also sets aside spare sectors not visible to the operating system. The controller can be told to change each bad sector logically w

What is the resolution of this DAC, A 5-bit DAC produces an output voltage ...

A 5-bit DAC produces an output voltage of 0.2V for a digital input of 00001. Find the value of the output voltage for an input of 11111. What is the resolution of this DAC? Ans

What are the types of assemblies, What are the Types of Assemblies? One...

What are the Types of Assemblies? One of the drawback of using Visual Studio.NET and the .NET framework to develop applications has been the lack of cross-platform support. As

Determine the define byte - assembler directives, Determine the Define Byte...

Determine the Define Byte - Assembler directives DB (Define Byte): DB directive defines a byte-type variable (i.e. a variable that occupies one byte of memory space). In a give

Data dictionary, data dictionary for online banking system in software engi...

data dictionary for online banking system in software engineering

Add the equation by using 648 and 487 in bcd code, Add 648 and 487 in BCD c...

Add 648 and 487 in BCD code. Ans. In BCD Code, addition of 648 and 487: 6 4 8  =  0 1 1 0   0 1 0 0      1 0 0 0 4 8 7  =  0 1 0 0   1 0 0 0      0 1 1 1 ---------------------

How debugger works internally, Whenever we compile with -g option, it will ...

Whenever we compile with -g option, it will make a symbol table, and according that table for every function and line it will call ptrace.

What are the type of internet connection, What are the type of Internet con...

What are the type of Internet connection When determining requirements for a VPN, carefully estimate the number of systems to be put behind the VPN, the number of concurrent u

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