Beyond End-to-End: Cryptography That Defends Against Tomorrow’s Threats
Secure Cryptography in Privora – Local, In Transit, and Post-Quantum Ready
In a world where digital communication is increasingly monitored, analyzed, and stored, Privora deliberately takes a radically different path. Our cryptographic architecture is designed to offer not just immediate protection, but also long-term resilience – even in the face of future threats like quantum computing.
This article outlines how Privora secures communication on three levels: local storage, peer-to-peer transmission, and forward-looking cryptography.
1. Local Encryption
All sensitive user data – including messages, contacts, settings, and cryptographic keys – is encrypted directly on the device using the well-established AES-256 standard. The encryption key is derived locally from the user’s private access code and is never stored in plaintext or transmitted.
How secure is AES-256?
Let’s break it down:
Total possible keys:
2^256 ≈ 1.16 x 10^77Even with a theoretical supercomputer checking 10^18 keys per second, brute-forcing AES-256 would take: ≈ 3.67 x 10^52 years
That’s trillions of times longer than the universe has existed (~13.8 billion years). In practice, AES-256 is unbreakable by brute force.
2. Transport Encryption via Tor
Privora uses a hybrid encryption model for data transmission:
Each message is encrypted using a symmetric key, established via Elliptic Curve Diffie-Hellman (ECDH) using Curve25519.
All communication takes place over the Tor network, using Onion Services (hidden services).
This ensures that both the message content and the metadata – such as sender/receiver IP addresses – are anonymized and protected from surveillance.
How strong is ECDH over Curve25519?
This setup offers a 128-bit security level.
Brute-forcing a single key would still take more than 10^30 years with today’s computing power.
3. Planned Feature: Asynchronous Delivery
Currently, Privora requires both peers to be online and reachable through Tor to exchange messages. In the future, we aim to support asynchronous messaging, where encrypted messages are stored locally and only sent once the recipient is available via Tor.
Importantly, this will be implemented without any central server or cloud buffer, keeping Privora fully decentralized and privacy-respecting.
4. Emergency Wipe Function
Privora features a built-in Emergency Code. If entered, the app will immediately and irreversibly delete all encrypted data – including the AES master key and all locally stored content. Optional secure overwrite routines ensure no trace remains, even under forensic inspection.
5. Post-Quantum Cryptography (In Development)
Quantum computers pose a serious threat to traditional encryption algorithms, especially RSA and ECDH. Privora is actively testing the integration of Kyber, a lattice-based encryption scheme selected by NIST as a post-quantum standard.
Example: How quantum computing affects encryption
A large enough quantum computer using Shor’s algorithm could break ECDH keys in minutes to hours.
AES is more resilient, but its effective strength is halved under Grover’s algorithm – AES-256 becomes roughly equivalent to AES-128, which is still considered secure.
By introducing Kyber, Privora prepares for a future where quantum-resistant encryption is no longer optional, but essential.
Conclusion
At Privora, cryptography is not a feature – it’s the foundation. By combining:
full local encryption,
anonymous peer-to-peer transmission over Tor,
decentralized architecture,
emergency self-destruction features,
and post-quantum readiness,
Privora delivers a messaging platform that respects your privacy – not just today, but in the decades to come.
