deBeam - Secure File Transfer

deBeam transfers files directly between devices over local Wi-Fi at full network speed.

--- HOW IT WORKS ---
Pairing takes just 3 seconds.
The receiver taps "Receive" to show a QR code.
The sender scans it and taps "Send".
Done. No usernames, no pairing codes, no waiting for cloud servers.

--- WIRELESS TRANSPORT MODE ---
Wi-Fi LAN (Same Network / Hotspot)
Already on the same router or connected via a Mobile Hotspot? deBeam uses your existing local network path. Every device keeps its own IP, eliminating IP collisions. Fully cross-platform: transfer between iOS, iPadOS, macOS, and other mobile or desktop platforms with no setup required.
Real-world speed: 50-100 MB/s. A 1 GB video transfers in under 20 seconds.
High-performance local streaming without routing bottlenecks or cloud dependency.

--- PROTOCOL-LEVEL END-TO-END ENCRYPTION ---
Security in deBeam is the protocol itself, implemented at the lowest native layer.
Key Exchange - X25519 ECDH
Every session generates a new keypair from scratch using random bytes from the OS secure random number generator. The receiver's public key is embedded in the QR code. Scanning performs an X25519 Elliptic Curve Diffie-Hellman exchange, producing a shared secret that exists only on those two devices for that one session.
The attacker space is 2^255 - computationally impossible to brute force.
Key Derivation - BLAKE2b
The shared secret is processed through BLAKE2b with the context string "deBeam-v3-session". This binds the derived key strictly to this protocol version, preventing key reuse or replay attacks.
Encryption - ChaCha20-Poly1305 (AEAD)
Every byte of your files is encrypted with ChaCha20-Poly1305. Files stream in 1 MB chunks, each with a unique nonce derived from its file index and chunk position.
No nonce reuse: No two chunks ever share a nonce - cryptographic reuse attacks are impossible.
Integrity: Each chunk carries a 16-byte Poly1305 authentication tag. Any tampered or replayed chunk is instantly detected and the connection terminates.
Memory Security - crypto_wipe()
After the key exchange, ephemeral private keys and session keys are immediately wiped from memory using crypto_wipe(). Past sessions cannot be recovered even if the device is compromised later.
Threat Coverage
Eavesdropping: Blocked by ChaCha20-Poly1305 encryption.
Man-in-the-middle: Blocked by X25519 (cannot forge secret without private keys).
Rogue device: Impossible without the QR-embedded public key.
Brute force: 2^255 key space - mathematically infeasible.
An 8-byte visual key fingerprint ("A1B2-C3D4...") on the receiver's screen allows quick visual verification before files move.

--- NATIVE PERFORMANCE ---
The encryption and streaming engine is written via native integration using Monocypher 4.0.2 - a compact, audited crypto library. ChaCha20-Poly1305 runs at ~500 MB/s on ARMv8. Encryption overhead is zero compared to Wi-Fi throughput - no speed penalty for maximum security.

--- NO SERVER. NO CLOUD. NO ACCOUNT. ---
deBeam has no backend infrastructure. No signup, no login, no tracking, no telemetry. QR pairing is computed entirely on-device and works 100% offline. Files travel directly from sender to receiver.

--- CORE FEATURES ---

Send multiple files in a single session

All file types: videos, photos, docs, archives, RAW files, and custom formats

Persistent local storage - chosen destination saved securely via Security-scoped Bookmarks

No file size limit

QR code pairing - no manual IP entry, no accounts

Visual key fingerprint for authenticity verification

Files saved securely to system Downloads or custom user-defined directory

Real-time transfer progress per file

Full cross-platform support across mobile and desktop devices
deBeam. Beam it.

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https://devitan-docs.gitbook.io/devitans-apps/x.-privacy-policy-for-devitans-apps

Terms of Use (EULA):
https://www.apple.com/legal/internet-services/itunes/dev/stdeula/