Encryption-Decryption

A console-based program that encrypts and decrypts text using simple algorithms.

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Features

• Encryption & Decryption of text using:
  • Shift algorithm (Caesar cipher style, A→B→C…)
  • Unicode algorithm (based on character codes)
• Command-line arguments:
  • -mode → enc or dec
  • -key → shift amount
  • -data → direct text input
  • -in / -out → file input/output
  • -alg → algorithm (shift or unicode)
• Supports both direct input and file input/output
• Graceful error handling for missing or invalid arguments
• Default values when arguments are omitted

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Technologies & Concepts

• Java 11+
• OOP & modular design
• String and character operations
• Command-line parsing
• File I/O (read & write)
• Error handling and defaults

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Example

Encrypt with shift algorithm:

java -jar encryption-decryption.jar -mode enc -key 5 -data "Hello World!" -alg shift