nSealr Key

Daily-use connected touch signer with USB/display review and bridged NIP-46 inputs. One universal Rust firmware runs across the curated Waveshare ESP32-S3-Touch-LCD family, hardened with Secure Boot v2 + Flash Encryption and no discrete secure element — many devices, one firmware.

Hardware family

The universal firmware targets four curated boards, distinguished by display size and role:

• Waveshare ESP32-S3-Touch-LCD-2.8 V2 — 240×320 IPS, the primary reference board.
• Waveshare ESP32-S3-Touch-LCD-1.69 — 240×280, the compact board.
• Waveshare ESP32-S3-Touch-LCD-2.0 — 240×320, the standard board.
• Waveshare ESP32-S3-Touch-LCD-3.5B — 320×480, the premium board.

Boundaries

• The companion handles NIP-46 bridge decisions via nsealr nip46 decide; the device receives already-decrypted, validated signing requests.
• USB transport uses bounded frames with request-bound capture checks. Bring-up is covered by nsealr serial-line exchange.
• Smoke evidence: companion-to-device serial smoke, sign-event-disabled smoke, firmware protocol evidence, Unicode fallback tracking.
• signing_disabled until hardening gates pass; approvals are bound to approval_digest.

Secret lifecycle

Unlike the QR vaults, the Key holds a persistent secret in encrypted flash (Flash Encryption). The seed is generated on device or imported from BIP-39 words. A device PIN — firmware-enforced and rate-limited — gates use of the key. Backup-at-creation exports BIP-39 words plus a SeedQR on the trusted display, one-time, at seed creation. An optional BIP-39 passphrase is supported.

Repository

github.com/nSealr/esp32