Senior Hardware Engineer – Air-Gapped Crypto Wallet Company: Cold Crypt

Company: Cold Crypt

Location: Remote (initially) → Tampa, Florida (hybrid/in-office after initial phase)

Type: Full-time / Contract-to-hire

Cold Crypt is building a next-generation, defense-grade, air-gapped hardware wallet designed to redefine crypto security.

Our mission is to combine:

• Military-level protection
• Premium, consumer-grade experience
• True non-custodial ownership

The device will integrate advanced features such as:

• AI-powered voice interaction
• Multi-factor authentication (biometrics PIN voice)
• Real-time anomaly detection

All while ensuring that private keys never leave a secure, offline environment.

We are seeking a Senior Hardware Engineer to lead the architecture and development of our flagship device.

This is a foundational role, working directly with leadership and collaborating closely with software and security teams to bring a highly secure, air-gapped wallet from concept to production.

• Design and develop the complete hardware architecture for a secure, air-gapped crypto wallet
• Select and integrate:
• Secure element chips
• Microcontrollers
• Biometric sensors
• Voice input hardware
• Tamper-resistant components
• Ensure true air-gapped operation, including offline transaction signing (QR-based or equivalent)
• Implement advanced physical security protections, including:
• Side-channel attack mitigation
• Tamper detection and response
• Secure key storage architecture
• Collaborate with software engineers on:
• AI voice control integration
• Anomaly detection systems
• Lead:
• Component sourcing
• Schematic design
• PCB layout
• Prototyping and testing
• Support transition from prototype → production, including manufacturing considerations
• Work toward applicable security certifications (e.g., Common Criteria EAL5 /EAL6 )

• Strong experience in embedded systems and secure hardware design
• Hands-on experience with secure element chips (e.g., ATECC608, OPTIGA Trust, STMicroelectronics secure elements)
• Proven experience with or deep understanding of:
• Crypto hardware wallets OR
• Air-gapped systems / high-security devices
• Proficiency with:
• PCB design tools (Altium, KiCad, or similar)
• Microcontrollers (e.g., STM32 or equivalent)
• Hardware-based cryptography
• Solid understanding of:
• Side-channel attacks
• Tamper resistance techniques
• Secure boot and firmware integrity
• Ability to work remotely initially and collaborate in person in Tampa as needed

• Direct experience building or contributing to a crypto hardware wallet
• Experience with air-gapped transaction systems (QR-based signing, offline flows)
• Knowledge of biometric systems (fingerprint, facial recognition, voice anti-spoofing)
• Experience with low-power design and battery management
• Familiarity with secure manufacturing and supply chain considerations

• Competitive salary equity
• Token allocation ($COLD)
• Opportunity to build a category-defining security product
• Early-stage, high-impact role with direct influence on architecture and design
• Remote-first flexibility with future Tampa-based collaboration

If you’re excited about building one of the most secure hardware wallets on the market, please send:

• Your resume
• Relevant project links (GitHub, hardware portfolio, case studies)
• A short note on why you’re a strong fit