Secure File Sharing System
An encrypted file exchange platform using hybrid AES and RSA cryptography with expiring links and full audit logging.
Project overview
Files are encrypted with a random AES key before leaving the sender's browser or server; that key is itself encrypted with the recipient's RSA public key. The server stores only ciphertext, so a database breach exposes nothing useful.
The hybrid scheme is the academic centre of the project — it demonstrates why symmetric and asymmetric cryptography are combined rather than used alone, which is a question examiners ask constantly.
Problem statement
Sensitive documents are routinely shared through email attachments and messaging apps, where they are stored in plaintext on servers outside the sender's control, with no expiry and no record of who opened them.
Proposed solution
Generate a per-file AES-256 key, encrypt the file with it, encrypt that key with the recipient's RSA public key, and store only the ciphertext and the wrapped key. Add expiring download links, download limits, integrity verification and an audit log of every access attempt.
Key features
- Per-file AES-256 encryption with a randomly generated key
- RSA key wrapping so only the intended recipient can decrypt
- SHA-256 integrity check verified on download
- Expiring share links with a maximum download count
- Optional password protection as a second factor
- Complete audit log of uploads, downloads and failed attempts
- Automatic deletion of expired files
Technology stack
Cryptography
Backend
Front end
Storage
System architecture
The flow below is what goes into your architecture diagram and the corresponding chapter of the report.
- Key management generates an RSA keypair per user at registration
- Upload path generates an AES key, encrypts the file and wraps the key with the recipient public key
- Storage layer holds only ciphertext plus metadata and the wrapped key
- Share layer issues a signed, time-limited download token
- Download path verifies the token, unwraps the key with the recipient private key and decrypts
- Audit layer records every action with actor, timestamp and outcome
Expected output
- Working encrypted sharing portal with expiring links
- Audit log showing every access attempt
- Demonstration that stored files are unreadable without the key
- Encryption and decryption timing measurements by file size
Suitable branches, difficulty and duration
Documentation, review, demo and viva support
Documentation support
Abstract, problem statement, literature survey guidance, system architecture, ER and UML diagrams, module descriptions, test cases and screenshots — prepared in your department format.
Project review support
Delivery is split across your review calendar so review one has a design and plan, review two has working modules, and the final review has the integrated, tested system.
Demo support
A rehearsed demo path, seeded sample data, a reset script, and a recorded walkthrough kept as a backup in case something fails in the review room.
Viva preparation
A written question bank for this domain, a code walkthrough session, and practice at explaining each module in your own words — because the examiner will ask you.
Customisation options
Colleges reject duplicate topics, so most projects are adjusted before we start. These are the usual directions for this one.
- Add group sharing with key wrapping for multiple recipients
- Add end-to-end encryption fully in the browser using the Web Crypto API
- Add steganographic watermarking to trace leaked documents
- Add two-factor authentication for account access
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Enquire about the Secure File Sharing System project
Send your branch, college and first review date. You will get confirmation of scope, what the customisation would look like, and a delivery plan mapped to your reviews.