# ZeroKeyUSB Docs

## Docs

- [API Introduction](https://docs.zerokeyusb.com/api-reference/introduction.md): Overview of the USB serial commands exposed by ZeroKeyUSB.
- [Certifications & Compliance](https://docs.zerokeyusb.com/certifications.md): Manufacturing standards and laboratory tests that validate ZeroKeyUSB for everyday and professional use.
- [Firmware Architecture](https://docs.zerokeyusb.com/firmware/architecture.md): Understand how the ZeroKeyUSB firmware is organized, from hardware drivers to the secure credential manager.
- [Flashing Protocol (WebTool)](https://docs.zerokeyusb.com/firmware/bootloader/flashing-protocol.md): The WebTool now acts as a simple loader that transfers the pre-signed binary to the device and manages the reboot.
- [Offline Signer Tool](https://docs.zerokeyusb.com/firmware/bootloader/signer-tool.md): Details on how the firmware is securely signed before distribution to ensure authenticity.
- [Integrity and Authenticity Verification](https://docs.zerokeyusb.com/firmware/bootloader/verification.md): The application verification process using hardware CRC32 and BLAKE2s MAC, including the penalty logic.
- [Display System](https://docs.zerokeyusb.com/firmware/display.md): How the OLED UI is rendered, animated, and kept clear while you browse your credentials.
- [EEPROM Management](https://docs.zerokeyusb.com/firmware/eeprom-management.md): Memory map, page layout, and read/write operations for the M24C64-WMN6TP credential storage.
- [Touch Input Handling](https://docs.zerokeyusb.com/firmware/io-touch-handling.md): How the capacitive keys are scanned, debounced, and mapped to menu navigation.
- [Menu System](https://docs.zerokeyusb.com/firmware/menu.md): Explore the ZeroKeyUSB menu structure, setup wizard, and how to use every feature safely.
- [AES-128 Encryption](https://docs.zerokeyusb.com/firmware/security/aes-128-encryption.md): Implementation details of the software AES-128 CBC cipher that protects every credential stored in ZeroKeyUSB.
- [Initialization Vector Generation](https://docs.zerokeyusb.com/firmware/security/iv-generation.md): How ZeroKeyUSB creates the AES-CBC IV using the ATECC608A TRNG, validates it, and handles regeneration.
- [PIN Verification](https://docs.zerokeyusb.com/firmware/security/pin-verification.md): Unlock flow, Counter0 hardware rate-limiting, SHA-256 hash comparison, and adaptive delays for the Master PIN.
- [Epoch Synchronization](https://docs.zerokeyusb.com/firmware/totp/epoch-synchronization.md): Keep ZeroKeyUSB’s internal clock aligned so TOTP codes stay valid.
- [Web Time Sync Tool](https://docs.zerokeyusb.com/firmware/totp/web-time-sync-tool.md): Use the browser-based helper to send accurate Unix time to ZeroKeyUSB.
- [USB Utilities](https://docs.zerokeyusb.com/firmware/usb-utilities.md): Keyboard emulation, serial commands, and backup/restore over the composite USB interface.
- [Creating Backups](https://docs.zerokeyusb.com/getting-started/creating-backups.md): Safely export, store, and restore credentials from your ZeroKeyUSB.
- [Importing Credentials](https://docs.zerokeyusb.com/getting-started/importing-credentials.md): How to load existing passwords, usernames, and TOTP secrets into your ZeroKeyUSB.
- [ATECC608A Secure Element](https://docs.zerokeyusb.com/hardware/atecc608a.md): Role, slot configuration, commands, and security properties of the ATECC608A in ZeroKeyUSB.
- [Display: SSD1306 OLED](https://docs.zerokeyusb.com/hardware/display-ssd1306.md): 128×32 monochrome display wiring, power budget, and firmware usage.
- [EEPROM Memory Map](https://docs.zerokeyusb.com/hardware/eeprom.md): How ZeroKeyUSB stores encrypted credentials and why its memory architecture is designed for maximum safety.
- [MCU: Microchip SAMD21](https://docs.zerokeyusb.com/hardware/mcu-samd21.md): Microcontroller responsibilities, clock setup, and peripheral usage inside ZeroKeyUSB.
- [Hardware Overview](https://docs.zerokeyusb.com/hardware/overview.md): Inside ZeroKeyUSB — industrial-grade components designed for offline security and long-term reliability.
- [Touch Sensor](https://docs.zerokeyusb.com/hardware/touch-sensor.md): The five golden points that replace buttons — a durable, intuitive interface for seamless control.
- [USB Interface](https://docs.zerokeyusb.com/hardware/usb-interface.md): How ZeroKeyUSB powers up, enumerates, and secures communications over USB-C.
- [ZeroKeyUSB Documentation](https://docs.zerokeyusb.com/index.md): Central hub for guides, hardware specs, firmware internals, and support resources.
- [Open Source & Transparency](https://docs.zerokeyusb.com/open-source.md): How we publish the firmware, schematics, and build process so you can verify — not blindly trust — ZeroKeyUSB.
- [Getting Started](https://docs.zerokeyusb.com/quickstart.md): Unbox your ZeroKeyUSB, set up your Master PIN, and store your first password — all in under five minutes.
- [FAQ](https://docs.zerokeyusb.com/support/faq.md): Answers to the most common questions about ZeroKeyUSB — security, compatibility, and daily use.
- [Troubleshooting](https://docs.zerokeyusb.com/support/troubleshooting.md): Recommended steps to diagnose and fix common issues with ZeroKeyUSB.

## Optional

- [Hardware Repo](https://github.com/Depbit-lab/zerokeyusb-hardware)
- [Firmware Repo](https://github.com/Depbit-lab/zerokeyusb)