Taybeti Notesharing

Taybeti keeps your secrets truly private. No plaintext ever touches storage. No password hash is kept on the device. Even the master login is verified by decrypting a known test string — there is nothing to crack.

Features

- Zero-trust master auth — no password hash, no Keystore, no persistent secrets - Per-note encryption — every note has its own passphrase and independent key - File encryption — encrypt any file (images, videos, documents) with AES-256-GCM + Argon2id - Encrypt from camera — capture and encrypt photos directly; no camera permission needed - Encrypt filename & extension — hide original name and replace extension with .taybeti - Confirm passphrase — double-entry field prevents typos when encrypting files - Covert sharing — disguise encrypted messages as a set of normal-looking YouTube/Instagram links - 100% offline — no internet permission, no cloud, no telemetry - Open source (MIT) — auditable by anyone, anytime

Security Architecture

- Key Derivation

Argon2id with 6 iterations, 64 MB of memory, and 4 lanes of parallelism.

- Encryption

AES-256-GCM with a random 32-byte salt, a random 12-byte IV, and a 128-bit authentication tag.

- Master Auth

Zero-trust canary: encrypt a fixed string and verify it by successful decryption.

- Per-Note Keys

Each note has its own passphrase, derived separately.

- Password Storage

char[] only, wiped with Arrays.fill(' ') after every use.

- Keystore

Not used; there is no Android Keystore and no hardware-backed key storage.

- Network

No internet permission in the manifest.

- Keyboard

Custom in-app keyboard only, with no system keyboard, suggestions, or learning.

- Screenshots

FLAG_SECURE is set on every Activity.

- Backup

android:allowBackup="false" and android:fullBackupOnly="false".

- Memory

onTrimMemory and onLowMemory immediately clear decrypted content.

- Logging

ProGuard strips all Log.d, Log.v, Log.i, Log.w, and Log.e calls in release builds.

- Decoy Vault

Optional decoy password unlocks a separate set of notes for plausible deniability.

Threat Model

Protects against:

- Physical device seizure (all data encrypted at rest) - Malicious apps on device (no IPC surface, FLAG_SECURE) - Keyboard logging / keyloggers (custom keyboard) - Screenshot / screen recording capture (FLAG_SECURE) - Android backup extraction (backup disabled) - Cloud sync leaks (no internet permission) - Google / OS-level key extraction (no Keystore) - Brute force (Argon2id memory-hard KDF, 5-attempt lockout)

Does NOT protect against:

- Compromised OS kernel / root-level malware - Hardware keyloggers - RAM forensic capture while a note is decrypted - Side-channel attacks on AES (software implementation)

License

Copyright © 2026 Cyberboy161

MIT