Zero Servers
AES-256-GCM
NO FIX — CAPTURE GPS
Lock Radius ~100 m
1 File
▶
2 Passphrase
▶
3 Location
▶
4 Seal
01 Select File
Drop file or click to browse
Never leaves this tab — zero server contact
02 Passphrase
—
key = PBKDF2(pw,salt,300k) ⊕ HKDF(SHA256(geo+geoSalt+fp))
03 Lock Radius
Decryption only succeeds within this radius of the lock point
04 Device Binding
factor selection override
⚠ Unstable factors may cause permanent decryption failure after display changes.
05 Lock Location
GPS
Signal No fix — press Capture
⚠ GPS accuracy too low. Move near a window and re-capture.
— Files sealed here can only be opened at this location. Coordinates are hashed with a random geo-salt — not stored in the bundle.
NO FIX — CAPTURE GPS
Mode DECRYPT
1 Load File
▶
2 Passphrase
▶
3 Location
▶
4 Unlock
01 Load Sealed File
Drop .labyrinth file or click to browse
Only files sealed by Labyrinth are accepted
02 Passphrase
Device binding factors are read from the sealed bundle — applied automatically.
03 Current Location
GPS
Signal No fix — press Capture
⚠ GPS accuracy low — decryption may fail even at correct location.
— Lock location is cryptographically hidden. Map shows only your current position.
Cryptographic Architecture — v2
I
Password → PBKDF2-SHA256 (300,000 iterations)

Passphrase stretched with a random 256-bit PBKDF2 salt. 300k iterations resists GPU brute-force. Iteration count stored explicitly in bundle for future migration.

password + pbkdf2_salt → PBKDF2(SHA-256, 300 000) → 32-byte pw_key
II
Location + Geo-Salt → Geo Key — offline brute-force impossible

GPS coordinates rounded to chosen precision, combined with a random 16-byte geo-salt (stored in bundle), user-selected device fingerprint factors, and timezone. The geo-salt means even perfect coordinate knowledge yields zero information without the salt.

"{lat_r}::{lon_r}::{geo_salt_hex}::{tz}::{fp}" → SHA-256 → 32-byte geo_key
III
Combine → HKDF (domain-separated key derivation)

Password key and geo key concatenated and run through HKDF-SHA256 with domain separation. Neither factor alone can decrypt.

[pw_key ‖ geo_key] → HKDF(SHA-256, "labyrinth-geo-vault-v1.0") → 32-byte final_key
IV
AAD — Metadata Cryptographically Authenticated

Filename, filesize, and precision hashed and passed as AES-GCM Additional Authenticated Data. Any metadata modification is detected — even a correct key rejects tampered metadata.

SHA-256({filename, filesize, precision, version:1}) → aad → AES-GCM additionalData
V
AES-256-GCM + Memory Wipe

AES-256-GCM, random 96-bit IV, 128-bit auth tag. Raw buffer zeroed with fill(0) after encryption. Wrong password and wrong location produce identical generic rejection.

file → AES-256-GCM(final_key, iv, aad) → ciphertext + auth_tag → rawData.fill(0)
Protected Against
ScenarioStatus
Stolen ciphertext alone✓ Protected
Stolen password alone✓ Protected
File + password, wrong location✓ Protected
Offline coordinate brute-force✓ Geo-salt
Bundle metadata tampering✓ Detected (AAD)
Lock location from file✓ Not stored
Known Limitations
VectorStatus
GPS spoof + geo-salt + coords⚠ Bundle required
Full device compromise (root)✗ Not covered
Browser memory forensics⚠ Mitigated
Adversary at same location⚠ Partial
Bundle Contents — Zero Location Data
Nothing geographic is stored. The .labyrinth bundle contains: encrypted ciphertext · PBKDF2 salt · AES IV · random geo-salt · filename · filesize · timestamp · precision · device factor IDs (not values) · versioned crypto params. No coordinates, no timezone, no fingerprint values of any kind.
AES-256-GCMPBKDF2-SHA256 HKDFAAD Auth Zero ServersGeo-Salt Coords Not StoredDevice Binding Memory WipedVersioned Params
Device Factor Stability
FactorStabilityChanged ByRec.
User AgentHighBrowser major updateAlways
LanguageVery HighManual changeAlways
PlatformMediumOS reinstallOptional
CPU CoresHighHardware onlyOptional
Screen ResolutionLowMonitor, scalingAvoid
AES-256-GCM
PBKDF2 × 300k
GEO-SALT
AAD-AUTH
Data that exists only where it belongs