Encrypt your cookies.
Deny the stealers.

K's Vault removes your session cookies from the browser's native store and encrypts them with AES-256-GCM. Malware that dumps your cookie database gets nothing.

Get it on Firefox View Source

The Problem

Your cookies are sitting unprotected on disk

Infostealer malware copies your browser's cookie database and sends it to an attacker. They paste your session tokens into their browser and access your accounts — no password needed.

Without K's Vault

Cookies stored in cookies.sqlite as plaintext. Any process running as your user can read them. Stealers extract and exfiltrate in seconds.

With K's Vault

Cookie store is empty for protected sites. Session tokens exist only inside AES-256-GCM encrypted blobs in the extension's IndexedDB. Stealers get useless ciphertext.


How It Works

Three steps to encrypted sessions

K's Vault sits between your browser and the server, handling encryption and decryption transparently on every request.

01

Choose sites to protect

Log into a site normally, then click "Protect this site." K's Vault migrates existing cookies into the encrypted store and deletes the originals.

02

Cookies are encrypted

Each cookie is encrypted with a unique derived key using AES-256-GCM. New cookies from the server are intercepted, encrypted, and stripped before the browser can store them.

03

Browse normally

On every outgoing request, K's Vault decrypts cookies in memory for milliseconds, injects them into the request header, and the server receives a valid session.


Features

Built by penetration testers

Designed around real-world attack scenarios we encounter during security assessments.

🔐

AES-256-GCM

Per-cookie key derivation using PBKDF2 + HKDF. 600K iterations. Non-extractable CryptoKeys via WebCrypto API.

🚨

Emergency Wipe

One click or Ctrl+Shift+K destroys all encrypted data permanently. Configurable auto-wipe after failed password attempts.

🌐

Domain-Aware

Protects root domain and all subdomains with a single click. Cookies from sso.example.com and www.example.com are covered together.

🔇

Zero Telemetry

No analytics, no network requests, no data collection of any kind. Everything stays on your device.

🔑

Password Re-entry

Configurable auto-lock timeout. Re-enter your password on browser start or at custom intervals.

📖

Open Source

Vanilla JavaScript, zero dependencies, no build tools. Every line is auditable. MIT licensed.


Architecture

How it's built

Vanilla JavaScript, WebCrypto API, IndexedDB. No frameworks, no dependencies, no supply chain risk.

// Project structure
lib/crypto.js ← PBKDF2, HKDF, AES-256-GCM
lib/storage.js ← IndexedDB encrypted blob management
lib/interceptor.js ← webRequest hooks for Set-Cookie / Cookie
background.js ← State manager, message router
popup/ ← Extension popup UI
settings/ ← Settings page

Incoming cookies

Server sends Set-Cookie → webRequest intercepts → value encrypted with per-cookie HKDF key → stored in IndexedDB → header stripped. Browser never stores plaintext.

Outgoing requests

Request to protected domain → encrypted cookies read from IndexedDB → decrypted with master key → injected into Cookie header → server receives valid session.

Key derivation

Master password → PBKDF2 (600K iterations) → non-extractable CryptoKey. Each cookie gets a unique key via HKDF using domain + name + timestamp as context.

Domain isolation

Compromising one cookie's key cannot reveal others. AAD binding prevents cross-domain tampering. Verification hash is cryptographically independent from encryption key.


Permissions

Why these permissions

Every permission is required for core functionality. None are used for data collection.

Permission Purpose
cookies Read, encrypt, and migrate cookies for domains you choose to protect
webRequest Intercept Set-Cookie response headers and Cookie request headers
webRequestBlocking Modify headers synchronously before the browser processes them
<all_urls> Operate on any domain you select — only activates for protected domains
storage Save your settings locally (protected domains, preferences)
notifications Alert you after an emergency wipe

Privacy Policy

Your data stays yours

Last updated: February 2025

Data Collection

K's Vault collects no data. Specifically:

Data Processing

All data processing occurs entirely on your device:

Data Storage

All data is stored locally using IndexedDB (encrypted cookie blobs) and browser extension storage (configuration). No data is stored on external servers, cloud services, or any location outside your browser profile.

Data Deletion

Third Parties

K's Vault does not integrate with, transmit data to, or receive data from any third-party services.

Contact

For questions about this privacy policy or K's Vault:
Website: kravex.ro
Email: contact@kravex.ro