Two passphrases.
One repeatable key.

KeyWeaver derives the same high-entropy cryptographic key from the same two passphrases — every time, on any machine. No salt to lose. No keyfile to back up. Just the recipe.

Get started View on GitHub → 
# Derive a VeraCrypt-compatible key with Argon2id
python keyweaver.py --kdf argon2id --veracrypt --fingerprint

Why KeyWeaver

Two-secret combiner

SHA3-256 and BLAKE2b-256 are computed independently per passphrase, then XOR-mixed with domain separation.

Three modern KDFs

Choose PBKDF2-SHA512 for portability, scrypt for memory hardness, or Argon2id for the modern best practice.

Fully deterministic

Same passphrases plus the same parameters always produce the same key. Re-derive on any machine, any time.

VeraCrypt-ready

Output as full hex, 32-byte VeraCrypt hex, or a binary keyfile written with restrictive permissions.

CLI and GUI

Scriptable command line for automation. Tkinter GUI for one-off derivations — no extra dependencies.

Safety guards

Strength meter, minimum-entropy enforcement, clipboard auto-clear, atomic keyfile writes, and a one-way fingerprint for cross-checks.

How it works

Two passphrases pass through independent two-hash constructions, are XOR-combined with domain separation, then stretched through a memory-hard KDF.

Passphrase 1
Passphrase 2
SHA3-256 ‖ BLAKE2bperson = VC2_P1
SHA3-256 ‖ BLAKE2bperson = VC2_P2
XOR — combined block (64 bytes)
KDF stretch (PBKDF2 / scrypt / Argon2id)
Final key — 128 bytes
  1. Two-hash construction. SHA3-256 and BLAKE2b-256 are unrelated families; concatenating their digests gives 64 bytes of mixed material per passphrase.
  2. Personalization. BLAKE2b's person parameter is VC2_P1 for the first passphrase and VC2_P2 for the second, so swapping inputs yields a different key.
  3. XOR combiner. The two 64-byte blocks are XORed. The result inherits the entropy of the strongest input.
  4. Deterministic salt. Salt = SHA512(label ‖ combined_block), preserving determinism.
  5. KDF stretch. PBKDF2-SHA512, scrypt, or Argon2id is run over the combined block to produce the final 128-byte key.

Install

Python 3.8 or newer. The Argon2id KDF requires argon2-cffi, which is included in the requirements file.

# Clone
git clone https://github.com/MuchDevSuchCode/KeyWeaver.git
cd keyweaver

# Install dependencies
pip install -r requirements.txt

# Run the CLI
python keyweaver.py --help

# Run the GUI
python keyweaver_gui.py

Common recipes

VeraCrypt 32-byte key, Argon2id, with fingerprint

python keyweaver.py --kdf argon2id --veracrypt --fingerprint

Binary keyfile, scrypt, restrictive permissions

python keyweaver.py --kdf scrypt --output-mode keyfile \
  --keyfile ~/secrets/vol1.key

Copy to clipboard, auto-clear in 60 seconds

python keyweaver.py --kdf argon2id --copy --copy-timeout 60

Refuse weak passphrases

python keyweaver.py --min-entropy 100

KDF parameter guidance

⚠ Parameters are part of the determinism contract. Pick once, write them down, and never change them for a given key — otherwise you cannot reproduce that key.

KDF Default Tighter Notes
PBKDF2-SHA512 iter=600 000 iter=2 000 000+ Stdlib only. No memory hardness.
scrypt N=16 384, r=8, p=1
≈16 MiB		 N=1 048 576
≈1 GiB		 Memory-hard. Strong GPU resistance.
Argon2id m=65 536, t=3, p=1
64 MiB		 m=1 048 576, t=4
1 GiB		 Modern best practice. Recommended for new deployments.

Security

Protects against

  • Disclosure of one passphrase alone.
  • Cross-context reuse (domain-separated personalization).
  • Race conditions on keyfile creation (atomic O_EXCL writes, mode 0600).

Does not protect against

  • Compromise of the running process (memory dumps, keyloggers).
  • Disclosure of both passphrases — by design.
  • Disclosure of the derived key or written keyfile.
  • Weak passphrases — pick long, high-entropy, non-reused secrets.

Memory wiping is best-effort: Python cannot reliably erase immutable strings. Internal buffers use bytearray and are zeroed after use. For high-value workflows, run on a system with encrypted swap and locked memory pages.

Try it

One file, one dependency, one deterministic key.

Get KeyWeaver →