January 2025 • Security Tools • v2.3

VaporDrop: Ephemeral Messaging That Actually Disappears

A RAM-only messaging system with end-to-end encryption. No database, no logs, no disk writes. Non-NIST cryptography designed by independent cryptographers. When the server shuts down, everything vanishes.

Most "ephemeral" messaging apps keep your data on disk somewhere. They call it "disappearing messages" but the messages just become invisible to you, not to forensic analysis, not to subpoenas, not to the server operator.

VaporDrop takes a different approach: if data doesn't exist, it cannot be seized. Everything lives in RAM. The server stores only encrypted blobs it cannot decrypt. When the server shuts down, reboots, or loses power, all messages vanish instantly.

How It Works

VaporDrop uses a brain key system for identity. You memorize 6 words. Those words become your cryptographic identity through key derivation:

Your brain key: "house cat moon pizza sea sun"
        ↓
Argon2id (100,000 iterations, 64MB memory)
        ↓
BLAKE3 key derivation
        ↓
X25519 key pair (public + private)

Same words always produce the same identity. No registration, no account creation, no email verification. You are your passphrase. Your public key becomes your numeric ID (like 12345678-90) that others can use to message you.

Why No NIST?

VaporDrop deliberately avoids all NIST-standardized cryptographic algorithms. This is not paranoia, it is a response to documented history:

• Dual_EC_DRBG: NIST standardized an NSA-backdoored random number generator in 2006. The backdoor was confirmed in 2013 via Snowden documents.
• Curve selection: NIST curves (P-256, P-384) have unexplained seed values. We use Curve25519, which has transparent, verifiable parameters.
• Process opacity: NIST's selection process for cryptographic standards lacks the transparency of academic peer review.

Instead, VaporDrop uses algorithms designed by independent cryptographers with publicly auditable designs:

Daniel J. Bernstein (djb) has a documented history of designing secure, efficient cryptographic primitives. His designs are public, auditable, and have withstood years of cryptanalysis.

Features

End-to-End Encrypted Messaging

Messages are encrypted client-side using X25519 key exchange and XChaCha20-Poly1305 authenticated encryption. The server never sees plaintext, it stores only encrypted blobs that it cannot decrypt.

File Transfer NEW

Send encrypted files up to 1 GB. Files are chunked, encrypted client-side with the same zero-knowledge architecture, and automatically deleted after 7 days.

Numeric ID & QR Code

Your identity is represented as both a 64-character hex public key and a short numeric ID (12345678-90) for easy sharing. Generate a QR code to share your identity in person without typing.

Contact Book

Save frequently used contacts locally in your browser. The server never sees your contact list.

Technical Implementation

Threat Model

What VaporDrop protects against

• Server seizure: Power off the server and all data vanishes from RAM instantly. There is nothing to image, nothing to analyze. Even while running, the server holds only encrypted blobs.
• Subpoenas for logs: No logs exist. You cannot hand over what does not exist.
• Traffic analysis: Random message padding (512-8192 bytes), randomized delays (50-500ms), constant-time operations.
• Replay attacks: Nonce-based request validation with 24-hour expiration and hash-based cache.
• NIST backdoors: We use zero NIST algorithms. All cryptography is from independent, auditable sources.
• Metadata collection: No accounts, no registration, no logs. The server knows only that some identity sent a message to some other identity.

What VaporDrop does NOT protect against

• Endpoint compromise: If your device is compromised, your messages are compromised. VaporDrop protects the transport and the server, not your laptop.
• Screenshot attacks: The person you are talking to can screenshot your messages.

Why Tor Only?

VaporDrop runs exclusively as a Tor hidden service. This is not because we could not set up HTTPS on the clearnet, it is because Tor provides properties that TLS cannot:

• Server location hidden: Nobody can determine where the server is physically located.
• No exit node: Traffic never leaves the Tor network, so there is no exit node to monitor.
• Self-authenticating addresses: The .onion address is derived from the server's cryptographic identity. No certificate authority required.
• Client IP hidden: The server never sees your real IP address.

Self-Hosting

For maximum security, run your own VaporDrop instance. The source code is available and the deployment is containerized:

git clone https://github.com/Virebent-do-ART/vapordrop.git
cd vapordrop
docker compose up -d --build

Your own .onion address will be generated automatically. See the GitHub repository for full documentation.

• • •

Source code: github.com/gabrix73
Questions and bug reports welcome.