Embedded Firmware Engineer for Secure Storage Device (Prototype)

Job ID: 40457991

Budget: $3,000 – $5,000 USD

Embedded Firmware Developer for Secure Storage Device (Prototype)

We're building a prototype of a small secure storage device — think along the lines of a hardware wallet, but for files instead of crypto keys. Looking for someone to help us put together a working PoC we can demo and test.

What we need:
Firmware for an ARM Cortex-M based device (we're planning STM32, open to suggestions)
Integration with a secure element for key storage (SE05x or ATECC608B)
Hardware-encrypted storage (AES on internal flash or external QSPI)
Simple UI on a small OLED display with a few buttons
USB mass storage interface for file transfer
Basic anti-bruteforce protection and secure boot

Background you should have:
Practical experience with STM32 (HAL or bare-metal, both fine)
Worked with a secure element or TPM before — even on a hobby project counts
Comfortable with AES, key derivation, basic crypto APIs (mbedTLS, wolfSSL, or similar)
Can read a datasheet and figure out things we haven't thought of

Nice to have (don't worry if you don't have all of this):
Hardware wallet / secure token / smartcard projects in your past
Familiarity with post-quantum crypto libraries (we may want to add ML-KEM later)
PCB / hardware design eye to spot issues early

Scope:
Small prototype, 3-5 working units. We'll handle PCB through a separate house — your work is firmware and crypto logic. Expect a 1-2 weeks of architecture discussions, then 1-2 months of building. We're flexible on hours and schedule, just want consistent progress.

To apply:
Tell us briefly what you've built before (links to anything public are welcome, but short descriptions are fine). Your hourly rate and rough availability. Any questions you have about the project.
Related categories: Cryptography Embedded Systems Prototyping STM32