Hospital Record Encryption (C)

Two complementary C programs that demonstrate secure collection and retrieval of patient records:

• Nurse Program – creates encrypted patient files.
• Consultant Program – retrieves and updates those files.

A project to showcase C programming, file I/O, and basic encryption concepts.

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Features

Nurse Program (nurse.c)

• Authenticates nurse with username and password (stored as Caesar-cipher text).
• Accepts patient first name, last name, date of birth, and notes.
• Encrypts and saves data to a file named <lastname><dob>_record.aow.

Consultant Program (consultant.c)

• Authenticates consultant credentials.
• Requests patient last name and DOB to locate the encrypted file.
• Decrypts, displays patient details, and optionally appends new notes.
• Re-encrypts and saves the updated record.

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File Structure

├── nurse.c              # Nurse-side program
├── consultant.c         # Consultant-side program
├── hospitalproject.pdf  # Full design and test report
└── README.md

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Build

Use any C11-compatible compiler (e.g. GCC or Clang):

gcc -std=c11 -O2 -Wall -Wextra -o nurse nurse.c
gcc -std=c11 -O2 -Wall -Wextra -o consultant consultant.c

This produces two executables: nurse and consultant.

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Run

Nurse Program

./nurse

You’ll be prompted for:

1. User (default demo: nurse)
2. Password (demo: nursepass)

Then enter patient details:

• First name
• Last name
• DOB (DDMMYYYY)
• Initial notes

The program creates an encrypted record file such as:

<lastname><dob>_record.aow

Consultant Program

./consultant

Steps:

1. Enter consultant credentials (demo user: consultant, password: consultpass).
2. Provide the patient’s last name and DOB.
3. View decrypted details and optionally add extra notes, which are re-encrypted on save.

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Example Session

== Nurse Login ==
User: nurse
Pass: nursepass

== New Patient Entry ==
First name: Alice
Last name: Smith
DOB (DDMMYYYY): 01012000
Initial notes: Routine check-up
Saved encrypted record: smith01012000_record.aow

Consultant side:

== Consultant Login ==
User: consultant
Pass: consultpass

== Open Patient Record ==
Last name: smith
DOB (DDMMYYYY): 01012000

-- Current Record --
First: Alice
Last: Smith
DOB: 01012000
Notes: Routine check-up
Add consultant notes (blank to skip): Follow-up in 6 months
Updated and re-encrypted.

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Documentation

Full design, implementation details, testing, and evaluation are provided in the project report:

Hospital Project Report (PDF)

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Key Learning Points

• C Programming: structured design, input validation, and modular functions.
• File I/O: creation, reading, and updating of structured text records.
• Encryption Basics: implementing a Caesar cipher for simple data protection.
• User Authentication: verifying credentials against encrypted password storage.

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Future Improvements

• Replace Caesar cipher with modern cryptography (e.g., AES via OpenSSL or libsodium).
• Improve input validation and error handling.
• Add unit tests and a Makefile for easier builds.
• Expand to a database backend (SQLite) for scalable record management.

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Developed by Pritam Gurung