BAR — Desktop

The problem

Journalists and lawyers handle time-critical confidential documents that must be provably destroyed after reading. No user-friendly offline tool existed that combined strong encryption with guaranteed deletion.

The solution

Architected a fully offline PyQt5 desktop app with AES-256-GCM encryption, PBKDF2 key derivation, and a timed self-destruct mechanism. All cryptographic operations run entirely on the local machine with zero network calls.

Outcome

Available as a standalone .exe requiring no installation. Achieves a fully zero-cloud architecture — data never leaves the local machine at any point in its lifecycle.

What I learned

Secure deletion on SSDs is harder than HDDs due to wear-levelling. Future version would overwrite file contents multiple times before unlinking. Also learned the value of threat-modelling before writing a single line of crypto code.

Stack

• Python
• PyQt5
• AES-256-GCM
• PBKDF2
• Cryptography