Custom Nostr Hardware Wallet With Persistent Secret

Research family for a purpose-built persistent-secret Nostr hardware wallet. The current Rev A direction is USB-C bus-powered, connected/no-wireless, no-battery, and TROPIC01-assisted. BIP-340 signing stays on the ESP32-S3 host MCU unless a public TROPIC01 API, firmware release, or written vendor path proves non-exportable Schnorr support.

Feature Target Current Contract
request_validation_v0 required planned signing-request-v0+implementation-limits-v0+invalid-vectors
nostr_event_review_universal required planned trusted-review-v0+review-detail-pages-v0
review_detail_pages required planned review-detail-pages-v0
approval_digest_binding required planned approval-digest-v0
physical_approval required planned physical-approval-v0
sign_event_bip340 required research nostr-sign-event-bip340-v0
persistent_secret_custody required research persistent-secret-custody-v0
secure_boot_hardening required research firmware-boot-hardening-v0
device_display_review required planned device-display-review-v0
response_verification required planned signed-response-verification-v0
stateless_session_custody forbidden forbidden

Rev A Boundary

  • No air-gapped claim: USB carries data.
  • No battery subsystem in Rev A.
  • persistent-secret-custody-v0 is now a checked lifecycle contract: no plaintext secrets at rest, wrapped/encrypted storage only before persistent custody, ESP32-S3 RAM-only plaintext after TROPIC01-assisted unlock, required wipe events, and disabled-by-default backup/export behind local review plus physical approval.
  • TROPIC01 is used for secure channel, TRNG, device authenticity, pairing lifecycle, MAC-and-Destroy PIN hardening, and key wrapping or unlock material.
  • Direct TROPIC01 Schnorr/BIP-340 remains future-gated, not a current capability claim.

Repository

Open hardware: github.com/nSealr/hardware. ESP32 firmware references: github.com/nSealr/esp32.