BlindLock Embeds Password Vault Inside PNG Files with Added Security Features

How BlindLock Stores Data Inside a PNG

BlindLock uses a form of steganography to conceal encrypted data within a standard PNG image. The image looks like any other picture and can be stored on a local drive, cloud storage or removable media without raising suspicion.

When the user opens the PNG with BlindLock, the application extracts the hidden payload, decrypts it with the master key, and presents the password vault, notes and crypto address book as a normal interface.

The technique relies on the fact that PNG files support optional metadata chunks that are ignored by most image viewers. BlindLock writes its encrypted blob into these chunks, keeping the visual representation unchanged.

For a deeper technical background on the method, see the article on steganography.

Encryption Process

Before data is hidden, BlindLock encrypts the entire vault with AES‑256 in GCM mode. The encryption key is derived from the user’s master password using PBKDF2 with 200,000 iterations, a salt stored in the PNG, and a strong hash function.

This approach meets the recommendations of the NIST digital identity guidelines for password‑based key derivation.

Key Security Features

BlindLock is not only a hidden vault; it bundles several security capabilities that are often found only in premium solutions.

• Secure notes that are encrypted alongside passwords.
• Two factor authentication (2FA) for vault access.
• Optional support for hardware security keys that follow the FIDO2 standard.
• A built‑in crypto address book for managing wallet addresses.
• Local‑only operation, meaning no data is ever sent to a remote server.

Two Factor Authentication

Users can enable 2FA with time‑based one‑time passwords (TOTP). The secret is stored inside the encrypted payload, so the second factor is only available after the master password has been verified.

Hardware Security Keys

BlindLock integrates with FIDO2 compatible devices such as YubiKey or SoloKey. When a hardware key is registered, the vault can be unlocked only if the physical token is present, providing protection against credential theft.

More information about the FIDO2 standard can be found on the FIDO Alliance website.

Using BlindLock in Practice

Below is a typical workflow for a new user.

1. Download the application from the official website.
2. Create a strong master password; a passphrase of at least four random words is recommended.
3. Select an existing PNG image or let BlindLock generate a blank placeholder.
4. Import existing passwords, notes or crypto addresses, or start adding new entries.
5. Enable 2FA and optionally register a hardware security key.
6. Save the PNG; the file now contains the encrypted vault.

Because the vault lives inside a regular image, it can be backed up with any standard file backup solution. Restoring simply requires opening the PNG with BlindLock and entering the master password.

Comparison with Traditional Password Managers

Most mainstream password managers store data in cloud‑based databases, rely on proprietary file formats, or require continuous internet connectivity. BlindLock differs in several respects.

• Local storage only – no server side component, reducing attack surface.
• Obfuscation – data is hidden inside an image, making it less likely to be targeted by automated ransomware.
• Open format – PNG is a universally supported file type, ensuring long‑term accessibility.
li>Hardware key support – many free managers lack native FIDO2 integration.

Security experts often warn that cloud synchronization can expose users to credential leaks if the provider is compromised. A recent analysis on Krebs on Security highlighted several high‑profile breaches of cloud password services.

Best Practices for Users

To get the most out of BlindLock, follow these recommendations.

• Choose a master password that is long, unique and not used elsewhere.
• Store the PNG in multiple secure locations, such as an encrypted USB drive and a personal backup folder.
• Enable both 2FA and a hardware security key for layered protection.
• Regularly review and update stored passwords, especially for accounts that have been compromised in the past.
• Keep the application updated to receive security patches and feature improvements.

By treating the PNG as a critical security asset rather than a casual image, users can maintain a high level of confidentiality while enjoying the convenience of a full‑featured password manager.