Another week, another update: https://github.com/keycard-tech/keycard-shell/releases

Shell supports Bitcoin Multisigs now.
Also, SeedQR import.

SLIP39 is definitely worth a consideration.

Our new release (v0.9.17) improves a couple of aspects of BIP39 Mnemonic entry: https://github.com/keycard-tech/keycard-shell/releases

Yes, multisig is planned for Shell until release in October. And, Shell's current fw supports UR2.0 and uses PSBT - so, you would be able to check networks based on derivation path

Technically, a private key never 'relies on a seed phrase' to be generated.

The BIP-39/BIP-32 flow: Random entropy -> mnemonic 'seed phrase' -> 512-bit seed -> Master key pair -> keys/addresses

So the random bytes come first. The seed phrase is just a human-readable encoding of that entropy.

What do does and could 'seedless' mean? What about Keycard?
1) The wallet doesn’t show you a mnemonic, or
2) The wallet doesn’t even store a mnemonic internally (it keeps only raw key material)

Not showing the words removes the classic paper backup. Great for physical-theft risk, bad if you lose the device.
Not having the words is merely an implementation choice. Security hinges on how the underlying secret is protected.

Tangem in its default setup is type (2): the secure element generates one ECC private key and clones it to 2-3 cards.
No BIP-32, which means you only get one address per asset. (there's a BIP-39 seed mode, which makes it 'non-seedless' if you will. but in that mode you only get the first address on each path.)

Keycard can be seedless (1) where you burn the paper after creating backup cards. Full BIP-32, so you can have as many addresses as you like.

We all agree that a pice of paper with 12 words is a single point of failure. That’s the gist of Zack Herbert’s argument as well: keep the secret encrypted, sharded, or inside hardware. I'm sure he'd like Keycard as encrypted backups.

I think I understand. Do you mean SEEDLESS in the sense that no display ever shows the seed phrase?

No, the current Shell firmware version does display the seed. Technically, it's possible not to.
But the team likes to see demand for that SEEDLESS mode, mostly because it's a trade-off in security.

Also, you can always simply burn your seed paper after creating multiple backup cards, which makes it SEEDLESS in a sense. But I guess not 100% in the sense you would like to have it. Does that make sense?

Shell allows for backup cards, too.
You can create a couple ^{or more} backup cards and then destroy your paper backup.

The main difference to Tangem is that Keycard allows you to add backup cards after the initial setup.

Mind that Tangem doesn't have a "Shell", but you need to use their close-source app. Which had a security vulnerability where imported private keys could be leaked ^{but that's for another day}

Thx for bringing that up! Parts of that table are confusing. Let us update it.

Essentially, Shell's "Open source secure element" and "Secure element has its own usages" means that Shell "has" Keycard, and Keycard has the SE. And the card itself can even be used standalone, via NFC.

The card can be managed with GlobalPlatform, an open standard. And the JavaCard runtime that is also an open platform with an open API. For a secure element even these two aspects are not a given.

Yes, a discounted €99 for Keycard Shell + two Keycards.

For 1 custom card, sure we can do it right away for the original price. Or for free if you have a fun project we should support.
For a custom Shell or large amounts of custom cards we can talk about price but also what logistics setup would work best for you.

Or, you could simply 3d print your own! Shell's hardware is open source, too:
https://github.com/keycard-tech/keycard-pro/tree/master/hw
https://x.com/vpavlin/status/1897971893979725884

These are all decent wallets! The one major difference is that Keycard is full stack open source, both card + wallet, Arculus and Cryptnox aren't.

I remembered CoolWallet as the one with display. But it turns out they plan a new one, a JavaCard from the looks of it. I haven't talked to them in a while, and the website doesn't mention the tech stack. But it looks like it's used for backups only. Via NFC. Interesting! Quite expensive for a feature you can just used Keycard for, though.


Shell can be used 100% air-gapped. No wired connection. You sign transactions by pointing Shell's camera to a wallet like UniSat, BlueWallet, ... etc. Then confirm on Shell's display & sign. Then let UniSat read the signature QR on Shell's display.

Fully air-gapped. Shell's usb port can 1) have data turned off 2) be used for charging only.

Keycard also works via NFC - with one open source EVM wallet - Status.im - for now.

Thank you!

Regarding Tangem. To keep it short and friendly I'd say we prefer Keycard's open source security model over Tangem's closed one.

Now, Satochip is interesting. Satochip and Keycard both have the NFC + chip combo.

With Shell we now add a camera + QR, which makes any Keycard work with: UniSat, BlueWallet, Sparrow, Backpack, imToken...
Technically, Keycard could be integrated with desktop wallets like Sparrow or Electrum. We just haven't gotten around to doing it, yet.
Of course we warmly invite anyone to contribute Keycard card reader support with Sparrow

For anything EVM, you can use Keycard with Status.im apps (mobile via NFC + desktop via reader)

Good point on interoperabilty! Technically, any JavaCard can work with Shell. I've pinged Satochip to see if they'd like to integrate. Again, our full stack is open to contribution 

Our security model is quite different. It's modular: Shell is kept as simple as possible, while Keycard has the SE.
Even during signing, the keys don't leave Keycard - unlike with a Trezor Safe 3 for example. Check out the examples we put on our blog: https://keycard.tech/blog/keycard-shell-radically-open-uniquely-secure , and especially the comparison table.

Keycard's SE is a standard JCOP4 by NXP - think credit cards, passports etc - with a proprietary part. Once there is a fitting, open source alternative, we would consider moving over.

USB data is turned off by default. If you like, you can keep that setting turned off, only ever use the usb port for charging, and use non-data cables only.

We are working on crypto payments. Mostly a legal thing. Sadly.

Keycard is a small part of IFT, some folks might know Status.

Keycard has been around since 2018, right. https://github.com/keycard-tech/status-keycard
The past year we've been building Keycard Shell - a shell to the cards, turning smart cards into fully-fledged hardware wallets: https://github.com/keycard-tech/keycard-shell

Jurisdiction is Switzerland.

Hey, we have been building Keycard as an open-source, JavaCard hardware wallet for a couple of years.

Now we’ve opened pre-orders for our new product Keycard Shell, which turns any Keycard into a fully-fledged, open-source hardware wallet.

What makes Keycard Shell unique from the sea of hardware wallets today?

The problem: Today’s common dual-chip designs export keys to a general-purpose MCU (and have been hacked - see Safe 3). Our Shell solution:

• Dedicated Secure Chip (Java Card): All transactions are signed inside a battle-tested, non-upgradable Java Card secure element – the same EAL6+ tech used in bank cards since the ’90s; one chip per Keycard
• Radical Open Source: Hardware & software are MIT-licensed – schematics, PCB layouts, BOM, Java Card applet, CAD files… audit, modify, even 3D-print your own case

Keycard Shell features

• 100% open source: transparent for you to build on, audit, and modify
• Unlimited Keys on Unlimited Cards: use multiple seeds or create secure backup cards; even ditching steal/paper backup for storing 10 cards in different locations (secured by PIN)
• Duress PIN: enter a second PIN under coercion to reveal a decoy wallet
• Air-Gapped QR Signing: sign offline with Shell’s camera & QR; no radio technology on board; USB exists for updates, and can be turned off
• Universal Compatibility: works with UniSat, BlueWallet, Sparrow, BackPack, imToken & 10+ more via BC UR and ERC-4527
• Future-Proof Design: replaceable Nokia BL-4C battery & modular cards for emerging crypto standards

As always, let us know your opinion! Check out our blog for a deep dive into thread scenarios and security trade-offs, and early prototypes.

And, we are taking pre-orders (w/ 50eur off), so feel free to check out https://keycard.tech