BitcastIn EP.1, we introduced you to popular and easy-to-use brands.
In EP.2, we explored the world of innovation and new features that transform the user experience.
But in this EP.3, we will delve deeper, into the world of Hardware Wallets that strictly adhere to the Self-Custody approach.

The brands we've selected for this EP. have one thing in common: they are not designed for "everyone," but only for those who "know what they're doing."

Some brands allow you to assemble the device yourself.
Some brands support nothing but Bitcoin.
Some brands only work with open-source software and cannot easily connect to anything online.

If you are a Bitcoin Maximalist, a developer, or someone serious about Sovereignty – this EP.3 is for you.


EP.3 Hardcore and Niche Brands

What criteria did we use for EP.3?

To systematically understand the world of Hardware Wallets, this Master List series divides brands into 3 groups. In EP.3, we focus on Hardcore / Open Source brands that emphasize self-control, selected based on the following criteria:

  1. Adherence to the principle of Sovereignty, or "the true power to hold assets."
  2. Compatibility with Open Source software such as Electrum, Sparrow, Specter, etc.
  3. Suitable for experienced users or those who prioritize high-level security.

This group consists of "Hardcore and Niche (unique) brands," suitable as an option for advanced users, especially Bitcoin Maximalists and developers, who wish to control certain processes themselves.

 

Overview of 10 Hardware Wallet Brands

This group comprises brands that may not be widely known but offer specialized and interesting concepts, suitable for users who require specific functionalities from a Hardware Wallet.

  1. Coldcard (coldcardwallet.com) – Designed exclusively for Bitcoin, operates air-gapped.
  2. Foundation (foundation.xyz) – Beautiful design, emphasizes full open-source ownership.
  3. Seedsigner (seedsigner.com) – DIY Hardware Wallet, self-buildable, uses QR camera for air-gapped operation.
  4. Specter Solution (specter.solutions) – Hardware and software for maximum secure and transparent Multisig.
  5. Satochip (satochip.io) – Ultra-thin smart card, supports Bitcoin and various tokens, open source.
  6. Prokey (prokey.io) – Easy-to-use hardware wallet, large screen, no separate app installation required.
  7. Corazon (gray.inc/collections/corazon-wallet) – Trezor Model T in a luxurious titanium body by GRAY for stylish crypto enthusiasts.
  8. BitLox (bitlox.com) – Durable e-ink screen, suitable for travelers or high-level portable users.
  9. Opendime (opendime.com) – USB Stick for Bitcoin as cash, one-time use.
  10. Blockstream Jade (blockstream.com/jade) – Created by Bitcoin Core Developer company, supports Blockstream Green.


Detailed Information for Each Brand

1. Coldcard

  • Country of Origin: Canada
  • First Launched: 2017 (developed by Coinkite Inc.)
  • Popular Models: Coldcard Mk4, Coldcard Q
  • Highlights:
    • Bitcoin-only wallet designed for "maximum security."
    • Supports air-gapped operation via MicroSD card.
    • Uses PSBT (Partially Signed Bitcoin Transaction) for signing transactions.
    • Features Secure Element + PIN + Anti-phishing login.
    • Fully compatible with software like Sparrow, Electrum, Specter.
  • User Experience:
    • Suitable for those serious about security, especially Multisig users.
    • Small screen but fully functional, clear commands, and abundant community guidance.
    • No Bluetooth, no touchscreen, no cloud — ultra secure.
  • Caveats:
    • UX not directly suitable for beginners; requires study of PSBT, seed setup, and microSD workflow for full efficiency.
    • Supports Bitcoin only.
    • May require preparing a microSD and additional accessories (e.g., Battery Pack, COLDPOWER Adapter) for air-gapped operation.


2. Foundation 

  • Country of Origin: United States of America
  • First Launched: 2021
  • Popular Models: Passport Batch 2
  • Highlights:
    • Bitcoin-only wallet, supports Bitcoin exclusively.
    • Beautiful "Digital Deco" design, inspired by Art Deco, features copper-colored metal buttons on a high-quality plastic body.
    • Uses QR code for transaction signing (Air-gapped); no USB, Bluetooth, Wi-Fi, or NFC, reducing wireless connectivity vulnerabilities.
    • Supports PSBT and Multisig.
    • Fully open-source, both hardware and software.
    • User-friendly UX features for technical users, such as selecting path/firmware via the screen.
  • User Experience:
    • Suitable for those seeking high-level security without the complexity of Coldcard.
    • Large, easy-to-use screen, supports Sparrow, Specter, BlueWallet.
    • High-quality packaging and manual, giving a premium feel.
  • Caveats:
    • No automatic backup phrase system — seed must be written down and stored manually.
    • Higher price than typical hardware wallets, suitable for those prioritizing security & UX.


3. Seedsigner

  • Country of Origin: United States of America
  • First Launched: 2021 (as a DIY project)
  • Popular Models: No ready-made models; must be assembled (SeedSigner kits)
  • Highlights:
    • Fully Open Source DIY Hardware Wallet.
    • No data stored on the device; operates "Stateless."
    • Uses a camera to scan QR Codes / create seeds manually (e.g., from dice).
    • Relatively inexpensive hardware, using Raspberry Pi Zero + camera + small display.
    • Fully compatible with advanced Bitcoin software such as Sparrow, Electrum, Specter.
  • User Experience:
    • Suitable for those who want to "know every step" of self-custody and multi-signature wallet setup.
    • Simple UI, comprehensive guidance from seed creation to PSBT signing.
    • User community and documentation on seedsigner.com provide complete walkthroughs and guides for both beginners and advanced users.
    • Requires some technical understanding for assembly and system setup.
  • Caveats:
    • Not suitable for beginners; no automatic backup system provided.
    • Device not certified by major manufacturers; users must assess risk themselves.
    • Requires self-assembly & configuration — not a ready-made device; requires basic knowledge of Raspberry Pi and Linux.


4. Specter Solution

  • Country of Origin: Germany
  • First Launched: 2020
  • Popular Models: Specter DIY
  • Highlights:
    • Both software and hardware for Bitcoin Self-custody.
    • Supports detailed Multisig, easy to use with Full Node.
    • Specter DIY uses an STM32-based device + QR Code for air-gapped transaction signing.
    • Fully open-source system, both GUI and Firmware.
    • Hardware components are readily available to reduce supply chain risks.
  • User Experience:
    • Suitable for users running a Full Node and wanting to control every step of the transaction process.
    • Compatible with Coldcard, Passport, Trezor, Ledger, SeedSigner.
    • Requires installing Specter Desktop and connecting to a Node.
  • Caveats:
    • Not suitable for Plug-and-Play beginners, as it requires understanding PSBT, multisig, node operation, and basic hardware assembly.
    • Not a standalone Hardware Wallet but an ecosystem.
    • Specter DIY requires self-assembly and is not yet fully mass-produced. If you prefer not to assemble it yourself, you might need to rely on third-party providers selling ready-made kits.


5. Satochip

  • Country of Origin: Belgium
  • First Launched: 2020
  • Popular Models: Satochip Card
  • Highlights:
    • Smartcard-based wallet similar to an ATM card.
    • Used with Satochip client or Electrum.
    • Supports Bitcoin, Ethereum, Litecoin, and various tokens.
    • Open-source software + card can be used with NFC readers.
  • User Experience:
    • Suitable for users who want a slim, convenient device while still controlling their keys.
    •  Easy to install: "plug or tap and use" via Satochip client or NFC reader on macOS/Windows/Linux/iOS/Android.
    • Card has PIN and backup system via BIP39.
  • Caveats:
    • Security depends on the smart card reader and associated devices.
    • No built-in screen → requires an external device to confirm transactions.


6. Prokey 

  • Country of Origin: Malaysia
  • First Launched: 2019 (product officially launched in 2020)
  • Popular Models: Prokey Optimum
  • Highlights:
    • Hardware Wallet focused on the easiest UX in the Open Source group.
    • No software installation required – works directly via Web Interface (WebUSB).
    • Supports Bitcoin, Ethereum, ERC-20, and over 3,200+ coins.
    • Open-source firmware and JS libraries.
  • User Experience:
    • Suitable for beginners who want to use an Open Source device.
    • Clear UI, large, easy-to-read screen.
    • Browser-based use means no separate app installation → very convenient.
  • Caveats:
    • WebUSB Phishing Risk – should only connect via the official website wallet.prokey.io to avoid risks from fake websites.
    • Does not yet support air-gapped or deep Multisig usage, compared to specialized devices like Coldcard.


7. Corazon (by GRAY)

  • Country of Origin: Singapore
  • First Launched: 2021 (official launch announced in collaboration with Trezor)
  • Popular Models: CORAZON® Titanium, CORAZON® Stealth Titanium, CORAZON® Gold Titanium
  • Highlights:
    • Essentially a Trezor Model T inside, but with a luxurious titanium body from GRAY.
    • High-quality titanium body, with the case made from sand-blasted titanium blocks or aluminum for various color models.
    • For users who want Trezor's features but with a high-end design.
    • Fully open-source, in line with Trezor standards.
  • User Experience:
    • Identical user experience to Trezor Model T in every aspect, including setup, transaction signing, and firmware updates via Trezor Suite.
    • Comes with a luxurious steel box and high-quality braided cable, suitable for gifting or corporate use.
  • Precautions:
    • Significantly higher price due to materials and design.
    • Technical features are no different from the standard model — no additional chips or new security features beyond the body change.
       

8. BitLox 

  • Country of Origin: Hong Kong
  • First Launched: 2015
  • Popular Model: BitLox Ultimate
  • Highlights:
    • Sleek, flat design made of durable metal. Only 4mm thin, like a credit card.
    • Uses an e-ink display, which is power-efficient and clearly visible even outdoors.
    • Supports Multisig and BIP39/BIP44.
    • Features multi-layer PIN system + data decoy + emergency mode.
  • User Experience:
    • Portable with an ultra-slim form factor, suitable for travelers and outdoor enthusiasts.
    • Easy to use via web interface or mobile app, without requiring heavy software installation.
    • E-ink screen saves battery and offers a minimalist aesthetic.
  • Precautions:
    • More complex UX than typical wallets; requires some learning time.
    • Some features may require BitLox's own desktop application.
    • Relatively high price compared to typical hardware wallets, but it offers premium materials and advanced features.


9. Opendime

  • Country of Origin: Canada
  • First Launched: 2014 (developed by Coinkite Inc.)
  • Popular Models: Opendime v3, Opendime v4
  • Highlights:
    • A "Bitcoin USB Stick" that can only be used once, similar to using a banknote.
    • Private Key is generated within the device and never revealed until "unsealed" by puncturing a hole on the device.
    • Used for offline Bitcoin transactions, like cash.
    • No internet connection or app required.
    • Easy to use – plug USB into computer → open HTML file on the device → view Bitcoin balance → instantly pass it on to others.
  • User Experience:
    • Ideal for "cold gifting" or physically transferring Bitcoin.
    • No apps or software installation required; simplicity similar to physical banknotes.
  • Precautions:
    • Single-use only. Once unsealed (punctured), the same Opendime cannot be used again; a new device is needed.
    • Not a hardware wallet for long-term portfolio management.
    • Physical security is crucial – if the device is lost before unsealing or accidentally opened, the stored Bitcoin will be lost.


10. Blockstream Jade

  • Country of Origin: Canada
  • First Launched: 2021 (developed by Blockstream Inc.)
  • Popular Models: Blockstream Jade Classic, Blockstream Jade Plus
  • Highlights:
    • Developed by Blockstream, the company behind Bitcoin Core Developers.
    • Features a color screen with a camera for air-gapped QR code scanning.
    • Fully open source – both hardware and software (firmware and companion apps) are available on GitHub for community review.
    • Supports Bitcoin-only with Liquid & Testnet.
  • User Experience: