Specifications

What's inside.

The full sheet — silicon, standards, and the physical object. Part numbers included, because you should be able to look everything up.

THE BOARDMODEL N°01 · ANNOTATED
Favilla KEY main board, annotated: ESP32-S3 WROOM-1U MCU, NXP SE051 secure element, OV2640 camera, BMA400 accelerometer, piezo buzzer, DRV2605L haptic driver, USB-C connector
The main board of a current prototype. Every component below is visible here.

Core silicon

Processor
Espressif ESP32-S3 (WROOM-1U module, external antenna)Dual-core Xtensa LX7 @ 240 MHz
Secure element
NXP SE051 · Common Criteria EAL 6+ with AVA_VAN.5Tamper-resistant key storage · on-chip PIN verification with hardware retry counter · certified TRNG
Camera
OmniVision OV2640, fixed-focus lens tuned for QR captureOn-device QR decode — used for airgap signing and pairing
Display
240 × 240 colour TFT (ST7789) behind cover glass
Motion
Bosch BMA400 accelerometerDrives the motion auto-lock
Feedback
DRV2605L haptic driver + piezo buzzerYou feel and hear every confirmation
Controls
Four tactile buttons

Power & connectivity

Battery
500 mAh LiPo · TI BQ24075 power-path chargingCustom power management with auto-sleep — days of mixed use, weeks in deep sleep
USB
USB-C (data + power)
WiFi
2.4 GHz b/g/n with WPA3 · own access-point modeAway from home, the device broadcasts its own network — your phone joins it directly
Bluetooth
BLE 5.0 hardware-capable, not used

Keys & cryptography

Recovery
One BIP-39 phrase (12 or 24 words) restores everythingNostr identity derives via NIP-06 · Bitcoin wallet via BIP-84 · existing nsec import supported
Entropy
Your choice at setup: SE051 certified TRNG, or your own dice rollsDomain-separated SHA-256 construction · dice path reproducible off-device · ESP32-S3 RNG folded into the SE path as unbudgeted margin
At rest
AES-256 ciphertext — decryption keys live inside the SE051A flash dump yields ciphertext and public data, nothing more
PINs
Two: daily (Nostr + watch-only) and spend (Bitcoin signing, device buttons only)Hardware retry counter, escalating lockouts, permanent lock after ten — recover from phrase
Signatures
BIP-340 Schnorr (Nostr) · ECDSA (Bitcoin)
Firmware integrity
Secure Boot V2, RSA-3072, permanently fusedProduction units add per-unit XTS-AES flash encryption — full security page

Nostr

Signing
NIP-01 events · policy per event kind: auto, manual, or selectiveEnforced by device firmware — a client cannot override it · policy mode (your own rules) coming
Messages
NIP-44 v2 encryption on every DM that leaves the device · NIP-17 gift-wrap end to endNIP-04 legacy: decrypt always, send opt-in only
Remote signing
NIP-46 for any client supporting Nostr ConnectOne-time bunker tokens · mint and revoke remotely, shown on the device screen
Zaps
NWC (Nostr Wallet Connect) — your node or a custodial serviceGift-wrapped zaps inside DMs
Client
Full Nostr client served from the device itselfLocal network or the device's own AP · remote client for NIP-46

Bitcoin

Wallet
BIP-32 / BIP-39 / BIP-84, multi-accountWatch-only under the daily PIN — balance and receive without exposing anything
Signing
PSBT · every input re-derived and verified, every change output checkedRefuses to sign anything it cannot prove is yours · spend PIN on device buttons only
Airgap
ur:crypto-psbt animated QR — camera in, screen out, no networkValidated round-trip against Sparrow and BlueWallet on mainnet

Physical

Enclosure
CNC-machined 6060 aluminium, anodised · 2 mm Gorilla Glass back panelPlanned finishes for later runs: stainless steel, copper, solid brass
Dimensions
55 × 55 × 17.5 mm
Weight
65 g
Assembled
Perth, Western Australia

And

CIPHER
Skill-based hash-mining game, built into the firmwareSigned scores, weekly sats draw — the full guide
Price
To be announced before launch
Availability
First production run 2026 · early-access list

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