Anyhide - Hide Anything in Anything

Hide anything inside anything. Anyhide is an advanced steganography and encryption tool that conceals any data (text, files, binaries) within any carrier file (images, videos, documents, executables) using hybrid encryption with forward secrecy and plausible deniability.

Why Anyhide?

Traditional steganography modifies the carrier file and transmits it. Anyhide is different:

Traditional Steganography	Anyhide
Modifies the carrier file	Never touches the carrier
Transmits the modified file	Transmits only a short code
Carrier can be analyzed	Carrier stays untouched
Hide text in images	Hide anything in anything

Use cases:

• Hide encrypted files inside a shared video
• Conceal sensitive documents using a public PDF as carrier
• Store secrets referenced by any file both parties have
• Covert communication with plausible deniability

How It Works

Anyhide uses a pre-shared carrier model:

1. Both parties have the same file (ANY file: image, video, PDF, text, etc.)
2. Sender hides data by finding byte patterns in the carrier
3. Only an encrypted code is transmitted - the carrier is never sent
4. Receiver uses the same carrier + code to extract the hidden data

┌─────────────────────────────────────────────────────────────┐
│  SENDER                         RECEIVER                    │
│                                                             │
│  carrier.mp4 ──┐                      ┌── carrier.mp4       │
│                │                      │   (same file)       │
│  secret.zip ───┼──► ANYHIDE CODE ─────┼──► secret.zip       │
│                │   (only this         │                     │
│  passphrase ───┘    is sent)          └── passphrase        │
│                                                             │
│  The carrier is NEVER transmitted                           │
└─────────────────────────────────────────────────────────────┘

Key Features

• Any carrier: text, images, audio, video, PDFs, executables, archives
• Any payload: text messages, binary files, documents, archives
• Dual-layer encryption: Symmetric (ChaCha20) + Asymmetric (X25519)
• Forward secrecy ratchet: Key rotation per message - past messages stay secure even if keys leak
• Ephemeral keys: Generate rotating keys for perfect forward secrecy
• Key fingerprints: Verify keys out-of-band (hex, emoji, visual art)
• Duress password: Two messages, two passphrases - reveal the decoy under coercion
• Message signing: Ed25519 signatures for sender authentication
• Message expiration: Auto-expiring messages
• Code splitting: Split codes for multi-channel delivery
• QR code support: Share codes via QR
• Plausible deniability: Wrong passphrase returns garbage, not an error
• Never fails: Decoder always returns something - prevents brute-force detection
• Library support: Use Anyhide in your own Rust projects

Installation

From crates.io

cargo install anyhide

Download Pre-built Binary

Download from GitHub Releases:

• Linux: anyhide-linux-x86_64 or anyhide-linux-aarch64
• macOS: anyhide-macos-x86_64 (Intel) or anyhide-macos-aarch64 (Apple Silicon)
• Windows: anyhide-windows-x86_64.exe

Build from Source

git clone https://github.com/matutetandil/anyhide.git
cd anyhide
cargo build --release

Quick Start

1. Generate Keys

anyhide keygen -o mykeys
# Creates: mykeys.pub, mykeys.key, mykeys.sign.pub, mykeys.sign.key

2. Encode a Message

# Using any text file as carrier
echo "The amazing Amanda went to the park yesterday" > carrier.txt

anyhide encode \
  -c carrier.txt \
  -m "ama park" \
  -p "secret123" \
  --their-key recipient.pub
# Output: AwNhYmNkZWZn... (send this code)

3. Decode a Message

anyhide decode \
  --code "AwNhYmNkZWZn..." \
  -c carrier.txt \
  -p "secret123" \
  --my-key recipient.key
# Output: ama park

Command Reference

Generate Keys

anyhide keygen [OPTIONS] -o <name>

Options:
  -o, --output <PATH>      Output path for keys (default: anyhide)
  --ephemeral              Generate ephemeral keys for forward secrecy
  --contact <NAME>         Contact name (required for consolidated storage)
  --eph-keys <PATH>        Path to .eph.key file (consolidated private keys)
  --eph-pubs <PATH>        Path to .eph.pub file (consolidated public keys)
  --eph-file <PATH>        Path to .eph file (unified storage)

# Long-term keys (default)
anyhide keygen -o mykeys
# Creates: mykeys.pub, mykeys.key, mykeys.sign.pub, mykeys.sign.key

# Ephemeral keys (individual files)
anyhide keygen -o alice --ephemeral
# Creates: alice.pub, alice.key (with EPHEMERAL PEM headers)

# Ephemeral keys (consolidated separate files)
anyhide keygen --ephemeral --eph-keys keys.eph.key --eph-pubs keys.eph.pub --contact bob
# Adds/updates contact "bob" in both JSON files

# Ephemeral keys (unified file)
anyhide keygen --ephemeral --eph-file contacts.eph --contact bob
# Adds/updates contact "bob" with my_private and placeholder their_public

Encode

anyhide encode [OPTIONS] -c <CARRIER> -p <PASSPHRASE>

Options:
  -c, --carrier <PATH>     Carrier file (any file type)
  -m, --message <TEXT>     Text message (or use --file for binary)
  -f, --file <PATH>        Binary file to hide
  -p, --passphrase <PASS>  Passphrase for encryption

Key options (choose one):
  --their-key <PATH>       Recipient's public key (.pub file)
  --eph-file <PATH>        Unified ephemeral key store (.eph)
  --eph-keys <PATH>        Separated ephemeral private keys (.eph.key)
  --eph-pubs <PATH>        Separated ephemeral public keys (.eph.pub)
  --contact <NAME>         Contact name (required with --eph-file or --eph-keys/--eph-pubs)
  -k, --key <PATH>         [DEPRECATED] Use --their-key instead

Ratchet options:
  --ratchet                Enable forward secrecy (auto key rotation)
  --my-key <PATH>          Your private key (for auto-saving next keypair)

Duress password (plausible deniability):
  --decoy <MESSAGE>        Decoy message revealed with --decoy-pass
  --decoy-pass <PASS>      Passphrase for the decoy message

Other options:
  --sign <PATH>            Sign with Ed25519 key
  --expires <TIME>         Expiration: "+30m", "+24h", "+7d", "2025-12-31"
  --split <N>              Split into N parts (2-10)
  --qr <PATH>              Generate QR code
  --qr-format <FMT>        QR format: png, svg, ascii
  --min-coverage <0-100>   Minimum carrier coverage (default: 100)
  -v, --verbose            Show details

Decode

anyhide decode [OPTIONS] -c <CARRIER> -p <PASSPHRASE>

Code input (choose one):
  --code <TEXT>            Direct base64 code
  --code-qr <PATH>         Read from QR image
  --code-file <PATH>       Read from text file
  --parts <FILES>...       Combine split parts (2-10 files)

Options:
  -c, --carrier <PATH>     Carrier file (same as encoding)
  -p, --passphrase <PASS>  Passphrase for decryption

Key options (choose one):
  --my-key <PATH>          Your private key (.key file)
  --eph-file <PATH>        Unified ephemeral key store (.eph)
  --eph-keys <PATH>        Separated ephemeral private keys (.eph.key)
  --eph-pubs <PATH>        Separated ephemeral public keys (.eph.pub)
  --contact <NAME>         Contact name (required with --eph-file or --eph-keys/--eph-pubs)
  -k, --key <PATH>         [DEPRECATED] Use --my-key instead

Ratchet options:
  --their-key <PATH>       Sender's public key (for auto-saving their next key)

Other options:
  --verify <PATH>          Verify signature with sender's public key
  -o, --output <PATH>      Output file (required for binary)
  -v, --verbose            Show details

Fingerprint

Display a key's fingerprint for out-of-band verification (like Signal/WhatsApp).

anyhide fingerprint <KEY_PATH> [OPTIONS]

Options:
  -f, --format <FMT>     Output format: hex, emoji, art, or all (default: all)

# Show all fingerprint formats
anyhide fingerprint alice.pub

# Show only emoji fingerprint (easy to compare by phone)
anyhide fingerprint alice.pub -f emoji

Output example:

Key: alice.pub

Hex Fingerprint:
  75EC37D4 51EBEDE4 E4AA4182 FD719560
  BE3E765C CE49A772 597A0ACF 09AC05FA

Emoji Fingerprint:
  🌲 🚂 🌺 🦊 🐺 ⛵ 🏎️ 🎻

Visual Fingerprint:
  +-----------------+
  |             o .o|
  |           .o ..+|
  |          . o..oo|
  |         + o .o..|
  |        S + +.+oB|
  |         . *.+o#+|
  |        .   O+=+B|
  |         . o.Oo= |
  |          E ..*  |
  +-----------------+

Other Commands

anyhide multi-encrypt    # Encrypt for multiple recipients
anyhide multi-decrypt    # Decrypt multi-recipient message
anyhide qr-generate      # Generate QR from code
anyhide qr-read          # Read code from QR
anyhide qr-info          # Check QR capacity
anyhide update           # Update to latest version

Examples

Binary Files as Carrier

Use any file (video, PDF, image, executable) as carrier:

# Hide text in a shared video
anyhide encode -c shared_video.mp4 -m "secret message" -p "pass" -k bob.pub

# Hide a ZIP file inside a PDF
anyhide encode -c document.pdf --file secret.zip -p "pass" -k bob.pub

# Extract hidden file
anyhide decode --code "..." -c document.pdf -p "pass" -k bob.key -o secret.zip

Message Signing

# Sign message
anyhide encode -c carrier.txt -m "From Alice" -p "pass" -k bob.pub --sign alice.sign.key

# Verify signature
anyhide decode --code "..." -c carrier.txt -p "pass" -k bob.key --verify alice.sign.pub
# Output: From Alice
# Signature: VALID

Message Expiration

# Message expires in 24 hours
anyhide encode -c carrier.txt -m "Temp info" -p "pass" -k bob.pub --expires "+24h"

# After expiration: returns garbage (not an error)

Code Splitting

# Split into 3 parts
anyhide encode -c carrier.txt -m "Secret" -p "pass" -k bob.pub --split 3
# Output: part-1: xxx, part-2: yyy, part-3: zzz

# Decode with all parts in order
anyhide decode --parts p1.txt p2.txt p3.txt -c carrier.txt -p "pass" -k bob.key

# Wrong order = garbage (plausible deniability)

QR Codes

# Generate code + QR in one step
anyhide encode -c carrier.txt -m "Secret" -p "pass" -k bob.pub --qr code.png

# Read QR and decode
anyhide decode --code-qr code.png -c carrier.txt -p "pass" -k bob.key

# Split QR codes
anyhide encode -c carrier.txt -m "Secret" -p "pass" -k bob.pub --split 3 --qr code.png
# Creates: code-1.png, code-2.png, code-3.png

Forward Secrecy Ratchet

Enable key rotation per message for perfect forward secrecy.

Ephemeral Key Storage Formats

Anyhide supports 3 storage formats for ephemeral keys:

Option 1: Individual PEM files (simple, single contact)

anyhide keygen -o alice --ephemeral
# Creates: alice.pub, alice.key (with EPHEMERAL headers)

Option 2: Separate consolidated JSON files (multiple contacts)

anyhide keygen --ephemeral --eph-keys mykeys.eph.key --eph-pubs contacts.eph.pub --contact bob
# mykeys.eph.key: JSON with your private keys for each contact
# contacts.eph.pub: JSON with each contact's public key

Option 3: Unified JSON file (recommended for chat apps)

anyhide keygen --ephemeral --eph-file contacts.eph --contact bob
# contacts.eph: JSON with both my_private and their_public per contact

Automatic Ratchet with Individual Files

# Step 1: Both parties generate ephemeral keys and exchange public keys
anyhide keygen -o alice --ephemeral   # Alice: alice.pub, alice.key
anyhide keygen -o bob --ephemeral     # Bob: bob.pub, bob.key

# Step 2: Alice sends message (keys rotate automatically)
anyhide encode -c carrier.txt -m "Hello Bob" -p "pass" \
    --their-key bob.pub --my-key alice.key --ratchet
# Output: Just the code (alice.key updated with next keypair)

# Step 3: Bob decodes (their public key updated automatically)
anyhide decode --code "..." -c carrier.txt -p "pass" \
    --my-key bob.key --their-key alice.pub
# Output: Hello Bob (alice.pub updated with her next public key)

# Step 4: Bob replies (keys rotate again)
anyhide encode -c carrier.txt -m "Hi Alice!" -p "pass" \
    --their-key alice.pub --my-key bob.key --ratchet
# Output: Just the code (bob.key updated)

Automatic Ratchet with Separated Stores

For environments where you want private keys and public keys in separate files:

# Step 1: Setup - create separated key stores
anyhide keygen --ephemeral --eph-keys alice.eph.key --eph-pubs alice.eph.pub --contact bob
anyhide keygen --ephemeral --eph-keys bob.eph.key --eph-pubs bob.eph.pub --contact alice
# Exchange initial public keys

# Step 2: Alice sends message
anyhide encode -c carrier.txt -m "Hello Bob" -p "pass" \
    --eph-keys alice.eph.key --eph-pubs alice.eph.pub --contact bob --ratchet
# Output: Just the code (alice.eph.key[bob] updated with next keypair)

# Step 3: Bob decodes
anyhide decode --code "..." -c carrier.txt -p "pass" \
    --eph-keys bob.eph.key --eph-pubs bob.eph.pub --contact alice
# Output: Hello Bob (bob.eph.pub[alice] updated with Alice's next public key)

Automatic Ratchet with Unified Store (Recommended)

# Step 1: Setup - create unified key stores for each party
anyhide keygen --ephemeral --eph-file alice.eph --contact bob
anyhide keygen --ephemeral --eph-file bob.eph --contact alice
# Exchange public keys initially

# Step 2: Alice sends message
anyhide encode -c carrier.txt -m "Hello Bob" -p "pass" \
    --eph-file alice.eph --contact bob --ratchet
# Output: Just the code (alice.eph[bob].my_private updated)

# Step 3: Bob decodes
anyhide decode --code "..." -c carrier.txt -p "pass" \
    --eph-file bob.eph --contact alice
# Output: Hello Bob (bob.eph[alice].their_public updated)

# Step 4: Bob replies
anyhide encode -c carrier.txt -m "Hi Alice!" -p "pass" \
    --eph-file bob.eph --contact alice --ratchet
# Output: Just the code (bob.eph[alice].my_private updated)

Key points:

• Messages are always clean - no key information displayed
• Keys rotate automatically after each encode/decode
• Use -v for verbose output if you need to see key details
• The --key flag is deprecated - use --my-key and --their-key instead

Library Usage for Chat Applications

use anyhide::{encode_with_config, decode_with_config, EncoderConfig, DecoderConfig};
use anyhide::{KeyPair, save_unified_keys_for_contact, update_unified_public_key};

// Initial setup: generate keys for Bob
let my_keypair = KeyPair::generate_ephemeral();
save_unified_keys_for_contact(
    "contacts.eph",
    "bob",
    my_keypair.secret_key(),
    &bobs_initial_public_key,
)?;

// Encode with ratchet enabled
let config = EncoderConfig { ratchet: true, ..Default::default() };
let result = encode_with_config(&carrier, "Hello!", "pass", &bobs_public_key, &config)?;

// result.next_keypair contains your NEXT key pair
// Save it for the next message you send
// result.code contains the encrypted message

// On receiving a reply, decode and get their next key
let decoded = decode_with_config(&code, &carrier, "pass", &my_secret_key, &DecoderConfig::default());
if let Some(next_key_bytes) = decoded.next_public_key {
    // Update Bob's public key for the next message
    let next_public = PublicKey::from(<[u8; 32]>::try_from(next_key_bytes)?);
    update_unified_public_key("contacts.eph", "bob", &next_public)?;
}

How the ratchet works:

1. Each message includes sender's NEXT public key
2. Recipient uses that key for the reply
3. Keys rotate with every message exchange
4. Compromised keys cannot decrypt past messages

Security Properties

1. Four-Factor Security: Carrier + Passphrase + Private Key + Correct Version
2. Never-Fail Decoder: Always produces output - no error signals for attackers
3. Plausible Deniability: Wrong inputs return garbage, not errors
4. Forward Secrecy: Ephemeral keys protect past messages
5. Code Splitting: Wrong order = garbage (no error)

Disclaimer

Anyhide is provided for educational and legitimate privacy purposes only.

This software is a tool, and like any tool, it can be used for good or bad purposes. The authors:

• DO NOT endorse or encourage any illegal activities
• ARE NOT responsible for how this software is used
• PROVIDE this software "as is" without warranty

You are solely responsible for ensuring your use complies with all applicable laws.

Documentation

• User Manual: This README
• Architecture & Development: ARCHITECTURE.md
• Version History: CHANGELOG.md

License

MIT License - see LICENSE for details.

Version

Current version: 0.8.1 (see CHANGELOG.md)