https://github.com/radeelahmad/ceaser-cypher
Encryption and decryption in Assembly language using the Irvine32 library
https://github.com/radeelahmad/ceaser-cypher
asm assambly ceasar-cipher encryption-decryption
Last synced: 3 months ago
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Encryption and decryption in Assembly language using the Irvine32 library
- Host: GitHub
- URL: https://github.com/radeelahmad/ceaser-cypher
- Owner: RadeelAhmad
- Created: 2024-07-23T08:33:06.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2024-08-10T19:14:51.000Z (10 months ago)
- Last Synced: 2025-01-13T08:12:04.365Z (5 months ago)
- Topics: asm, assambly, ceasar-cipher, encryption-decryption
- Language: Assembly
- Homepage:
- Size: 14.6 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Ceaser Cypher
This project implements Caesar Cipher encryption and decryption in Assembly language using the Irvine32 library. The program allows users to input a text file and a shift key, then either encrypts or decrypts the text based on the user's choice.
## Group Members
- [Radeel Ahmed](https://github.com/RadeelAhmad)
- [Muhammad Abdullah](https://github.com/iabdullah215)
## Project Structure
- `Irvine32.inc` and `macros.inc` are included for basic I/O operations.
- `BUFFER_SIZE` is set to 100 bytes to handle input data.
- `data` section contains necessary variables and prompts for user input.
- `code` section contains the main procedure and encryption/decryption logic.
## How to Run the Program
- **Compile and Link:** Use an assembler like MASM to compile and link the program.
```bash
ml /c /coff yourfilename.asm
link /subsystem:console yourfilename.obj Irvine32.lib
```
- **Execute the Program:** Run the compiled executable.
```bash
yourfilename.exe
```
- **Input Filename:** Enter the name of the input file containing the plaintext or ciphertext.
- Select Choice:
`Enter 1 for encryption.`
`Enter 2 for decryption.`
- **Enter Shift:** Input the shift key (a numerical value) for the Caesar Cipher.
- **View Results:** The program will display the ciphertext if you selected encryption or the plaintext if you selected decryption.
# Detailed Description
## Main Procedure
- Displays the project title and group member names.
- Prompts the user for the input filename.
- Opens the specified file and reads its contents into a buffer.
- Asks the user to choose between encryption and decryption.
- Prompts the user to enter a shift key for the Caesar Cipher.
## Encryption
- Iterates over each character in the buffer.
- Checks if the character is uppercase or lowercase.
- Applies the Caesar Cipher shift to each letter.
- Stores the encrypted characters in an array.
- Displays the resulting ciphertext.
## Decryption
- Iterates over each character in the buffer.
- Checks if the character is uppercase or lowercase.
- Applies the reverse Caesar Cipher shift to each letter.
- Stores the decrypted characters in an array.
- Displays the resulting plaintext.
## Example
```console
***********************
Project Caesar Cipher
***********************
---------------------------------------------------
Group Members
Radeel Ahmad - 221544
Muhammad Abdullah - 221546
-----------------------------------------------------
Enter an input filename: input.txt
Select Choice
1. For encryption
2. For decryption
Enter shift: 3
Plaintext is: HELLO
Ciphertext is: KHOOR
```
## Notes
- Ensure the input file exists in the same directory as the executable.
- The shift key should be a positive integer.
- The program only processes alphabetic characters; other characters are left unchanged.