KeycardDIY / stateless signing device

Keycard Shell

Name: Keycard Shell
Brand: Keycard

Keycard Shell is a DIY / stateless signing device released in 2025. Key specs: secure element chip, secure element certification EAL6+, open-source firmware, air-gapped signing.

5.0Score

Security9.2

Open source5.9

Bitcoin features2.6

Ease of use4.0

Connectivity9.2

price range€95–120

Full specifications

Year: 2025
Type: DIY / stateless signing device
Brand: Keycard
Popularity: #25 of 141

YesSecure Element chip

EAL6+Secure Element certification

YesOpen-source firmware

YesAir-gapped signing

USB-C, NFC, QR codeSigning connectivity

2″Screen size

YesBuilt-in battery

Specifications

Full specifications

Security

Secure Element chip: Yes
Secure Element certification: EAL6+
Air-gapped signing: Yes
100% air-gapped: No
Supply-chain & tamper protection: Yes
Secure boot: Yes
Anti-klepto (anti-exfil) signing: Yes

Firmware & open source

Open-source firmware: Yes
Source code available: Yes
Reproducible builds: Yes
Firmware licence: MIT
Upgradable firmware: Yes
Firmware update via: USB
Bitcoin-only firmware / edition: No

Device lock

PIN lock: Yes
PIN entered on the device: Yes
Fingerprint unlock: No
Duress PIN / decoy wallet: Yes
Brick / wipe PIN: No
Wipe after failed attempts: Yes
Time-delayed unlock: No
Anti-phishing words: No

Keys & backup

BIP39 passphrase: Yes
Shamir backup (SLIP-39): Yes
Seed XOR: No
BIP85 child seeds: No
24-word seed: Yes
SeedQR backup: Yes
microSD backup: No
NFC backup card: Yes
User-added entropy (dice): No
Stateless use (no stored keys): Yes
Multiple seeds on one device: Yes

Bitcoin features

Multisig: Yes
Taproot: No
Miniscript: No
Message signing: No
Coin control: Yes
Own node connection: Yes
Tor support: Yes
Replace-by-fee: Yes
Silent Payments: No
Spending limits: No
Testnet: Yes

Supported assets

Altcoins & tokens: Yes
Bitcoin only: No

Connectivity

Signing connectivity: USB-C, NFC, QR code
USB: Yes
USB-C: Yes
Bluetooth: No
NFC: Yes
QR code camera: Yes
Animated QR (UR): Yes
microSD signing: No

Screen & input

Screen: Yes
Screen size: 2″
Screen type: TFT IPS
Screen resolution: 240 × 320
Touchscreen: No
Colour screen: Yes
Gorilla Glass: No
Controls: Buttons
QWERTY keyboard: Yes

Battery & power

Built-in battery: Yes
Battery capacity: 800 mAh
Removable battery: Yes
Wireless charging: No

Design

Length: 105 mm
Width: 65 mm
Thickness: 19 mm
Materials: ABS Plastic
Several colours available: No
Warranty (months): 0
Assembled in: China
DIY build possible: Yes

Apps

Desktop app: No
Mobile app: No
Works with wallet apps: Bitcoin Safe, Nunchuk, Cove, Sparrow, Specter Desktop, BlueWallet, Bull
Compatible third-party wallets: 7

Other features