1. [Dynamic Key Control] Intelligent key management tailored to your needs.

The system automatically determines whether the recipient is “yourself” or “a third party or group” and applies the most appropriate logic.

• Personal (backup): Personal public key in the 4Login App seals the DEK, providing strong device-complete protection.
• Shared with others: Dynamically switches to the server key method, providing advanced access control that allows only specified groups or parties to securely decrypt.

2. [Zero-Knowledge Isolation] Thorough management to keep private keys.

Personal private keys are generated and stored in the ” 4Login App” secure area in the user’s smartphone. Since the private key is never taken out of the device in plain text, and is managed in encrypted form during backup, it is impossible for even the service operator to “know” the contents of the user’s data.

3. [Flexible Hybrid Design] Robust enough to adapt to future changes in standards.

The “encryption of the file itself (AES-256)” and the “layer protecting the key (DEK)” are completely separated. This structure prevents cipher obsolescence and allows only the key protection layer to be replaced with the latest quantum-resistant standard (ML-KEM) while maintaining existing performance.

4. [Identity authentication type sharing] Transition from “I know” to “I am”.

Eliminates the vulnerable process of “teaching” passwords to each other. Integrates the complex process of public key cryptography with 4Login authentication for a simple “just pick a destination” UX. Instead of a specification that anyone who knows the password can open it, it provides strict access control that allows decryption only when the designated “device of the person” is available.