Managing blockchain private keys is a critical challenge due to their complexity and the security vulnerabilities associated with online storage solutions. This paper presents a novel offline approach for securely storing blockchain private keys using the Arduino Nano 33 IoT integrated with biometric security. The system employs the ATECC608A cryptographic chip which supports Advanced Encryption Standard (AES-128) and Secure Hash Algorithm (SHA-256) for secure hardware storage and uses fingerprint authentication to restrict access to the private key. Unlike traditional password-based systems, our solution eliminates the need to memorize complex alphanumeric strings, enhancing security and usability. The system also supports an inheritance feature, allowing the private key to be linked to multiple fingerprints. This enables the owner to securely pass on access to their blockchain assets in the event of their death or incapacitation, addressing a key gap in existing blockchain key management solutions. To further improve user experience, we developed a custom Android application that enables secure key retrieval via USB communication. In addition to its robust security and ease of use, the system’ s low hardware complexity sets it apart from other solutions that require multiple devices or more intricate setups. Future work includes integrating this system with popular blockchain platforms like Ethereum and Binance to support multiple private keys and enable seamless interactions with digital wallets. This research contributes a highly secure, scalable, and user-friendly solution for managing blockchain private keys, specifically focusing on inheritance and biometric security.