Citadel Wallet Hardware Architecture

The design of Citadel Wallet's hardware was carefully researched and developed by studying existing hardware wallet solutions in the cryptocurrency market and other secure hardware technologies. Our goal was to identify the most secure, high-performing, power-efficient, and multi-functional integrated circuits (ICs) that would allow us to meet our design objectives and requirements. After months of analysis and comparison of architectures, we identified the best hardware components to be included in the Citadel Wallet hardware architecture.

There are several key factors we have focused on when developing hardware architecture for Citadel Wallet:

  1. Physical security: The primary focus when developing a crypto hardware wallet should be ensuring the security of user's assets. This includes implementing strong encryption techniques to secure the private keys, using secure hardware components like microprocessors and secure elements, and implementing measures to prevent physical tampering.

  2. Isolation from the internet: Hardware wallets are typically designed to be isolated from the internet, which helps to prevent them from being hacked or compromised by malware.

  3. Usability: A crypto hardware wallet should be easy for users to understand and use. This includes a user-friendly interface such as a large enough, high resolution and colorful display, clear instructions, and intuitive navigation using touch and buttons.

  4. Reliability: The hardware wallet should be reliable and have a long battery lifetime to ensure that users can access their assets when needed if using wireless communication options. Reliability also includes implementing robust software and hardware design, as well as regular maintenance and updates.

  5. Integration: The hardware wallet should be able to easily integrate with existing crypto exchanges and wallets, allowing users to seamlessly manage their assets. Hardware and software architecture should allow for standard and known to developers ways to interface with the secure device.

  6. Durability: A crypto hardware wallet should be designed to withstand wear and tear, and be resistant to physical damage, scratching. This will ensure that it remains functional and secure over time when exposed to vibration, humidity, hot and cold environments.

After months of development, we have successfully completed the design of the Citadel Wallet's architecture, which incorporates the best features from all of our initial design criteria. The final hardware design can be broken down to four primary functional blocks:


  • Secure M33 Dual Core Microcontroller

  • Common Criteria EAL6+ Certified Secure Element

  • Non-Volatile External Flash Memory

User Interface

  • 1.28" Round Full Color LCD with 240x240 resolution

  • Capacitive Touch screen for seamless user experience

  • Two push buttons to control power and approve transaction functions


  • Bluetooth 5.2 secure, low energy wireless communication

  • USB Type-C wired communication

  • NFC short distance communication


  • Device Charge and Power Delivery Management

  • Power On/Off Management

  • 200mAh Rechargeable Battery

Figure below represents high level hardware architecture of Citadel Wallet:

  • KMU - Key Management Unit

  • MPU - Memory Protection Unit

  • NVM - Non Volatile Memory

  • USB - Universal Serial Bus

  • NFC - Near Field Communication

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