diff --git a/_posts/2019-11-27-keycard-explained.md b/_posts/2019-11-27-keycard-explained.md new file mode 100644 index 0000000..456cefa --- /dev/null +++ b/_posts/2019-11-27-keycard-explained.md @@ -0,0 +1,111 @@ +--- +layout: post +title: The Keycard hardware wallet smartcard explained +cover: /assets/images/covers/keycard-explained.jpg +tags: +- keycard +- hardware wallet +- ethereum +- smartcard +--- + +> [Keycard](https://keycard.tech/) is a smartcard that comes with two pre-installed applications, the one the you use as an **hardware wallet paired with +your devices and authenticated with a PIN**, and the **Cash applet**, which can be used **straight away without any other device**. + +Keycard is a smartcard, not to be confused with other nfc tags or cards used only for storage or authentication. +It works like other hardware wallets, meaning that it's able to generate a private key that never leaves the card and can compute an +ECDSA signature internally. + +Smartcards are known for their very high level hardware security, leveraging all the work done in the banking/telecom/access control world for years, +allowing us to store wallet keys safely in that they never leave the card. +The [Keycard software](https://github.com/status-im/status-keycard) is an open-source Javacard applet. +All sensitive data exchanged between the card and the client, like authentication credentials, is sent over an encrypted secure channel. +The applet allows deriving keys and signing transactions for any cryptocurrency using the Secp256k1 curve and a 256-bit hash. + + +The two application pre-installed are the Keycard applet and the Cash applets. + +The **Keycard applet** implements a full hierarchical deterministic wallet that can be used after pairing the card with a device using a +pairing password that generates a pairing token subsequently used to open a [secure channel for each session to prevent MITM](https://status.im/keycard_api/sdk/securechannel.html); +after initialization the card contains a master key that remains on the card; +an API allows the user to use any valid derivation path to derive a key +that can be used to sign 32 bytes of data after authenticating with a PIN. + +The **Cash applet** is a simplified version of the Keycard applet; at installation time a normal (not extended) key is generated and it remains on the card; +it doesn't need to be paired or initialized with another device and can be used straight away to sign data. + +--- + +## About Keycard + +Some months ago we started distributing Keycards to developers, and in October we had a workshop at Devcon 5. + +

preparing some smartcards for tomorrow's @Keycard_ workshop here at #devcon 🇯🇵 pic.twitter.com/oG6N2TrM6B

— Andrea Franz (@gravityblast) October 8, 2019
+ +--- + +Some teams and developers already integrated Keycard in their projects, +like [Status](https://status.im/) (available after V1 is released), [Geth](https://twitter.com/peter_szilagyi/status/1135927489484791808?), +[Walleth](https://walleth.org/), [Gnosis Safe](https://twitter.com/StefanDGeorge/status/1189885553120104450), +[Grid+](https://github.com/GridPlus/safe-card), and others. + +

One step closer to the Geth v1.9.0 release! Just merged native support for all these beauties on #Linux, #macOS, #Windows and #FreeBSD! Shoutout to @gballet, @nicksdjohnson and @mr_ligi for the team effort of sorting all this out! 😎#golang #Ethereum @Ledger @Trezor @Keycard_ pic.twitter.com/1jSj3QmHO1

— Péter Szilágyi (@peter_szilagyi) June 4, 2019
+ +--- + +The [Keycard software](https://github.com/status-im/status-keycard) is **completely opensource** and can be installed +on any smartcard/javacard that meets [these requirements](https://status.im/keycard_api/applet_installation.html#Card-requirements). + +

Magic with @Keycard_ and @gnosisSafe: A true 2FA transaction is signed with a private key on the phone and in addition with a private key in a secure enclave on the Status keycard. The most easy-to-use multisig! It also works with dApps using @WalletConnect! https://t.co/zs8TjyClW1

— Stefan George (@StefanDGeorge) October 31, 2019
+ +--- + +Keycard is dual interface, NFC and contacts. You can interact with it selecting one of the two applets +and sending [APDU commands](https://en.wikipedia.org/wiki/Smart_card_application_protocol_data_unit). +If you don't want to send raw APDU command, you can use our [Java/Android](https://github.com/status-im/status-keycard-java), +[Swift/iOS](https://github.com/status-im/Keycard.swift), and [Go](https://github.com/status-im/keycard-go) SDKs. + +If you want to know more about the available commands, you can check the [Keycard API documentation](https://status.im/keycard_api/). + +When you buy a Keycard from [our website](https://get.keycard.tech/), you receive it with the Keycard and Cash applets pre-installed, +but you can use the [keycard CLI](https://github.com/status-im/keycard-cli) to re-install them or to install them on a different smartcard. +You can also use the CLI to send custom Keycard or standard Globalplatform commands, +like explained in an [introductory post](https://discuss.status.im/t/introducing-the-keycard-shell/1178). + +The main purpose of the Keycard is to be used as an hardware wallet with the Keycard applet, but we recently added a secondary Cash applet +that allows the owner to use it straight away without requiring a phone, for example to be used with a merchant point of sale or in +any other creative way... + +

Simple test app for a point of sale machine 💰 signing a meta transaction with the 💳 @Keycard_ cash applet 💵. The cash applet is a secondary app, the main one is still the hardware wallet app 🔐 that needs pairing password, pin, etc #ethereum #smartcard #hardwarewallet pic.twitter.com/Q9sISLoKwo

— Andrea Franz (@gravityblast) November 20, 2019
+ +--- + +...or just with a phone that a merchant wants to use as a point of sale: + + + +--- + +## The Keycard Applet + +When you receive the card the applet is installed but not initialized. +This means that it doesn't contain any key, and it needs to be initialized to be able to sign transactions. +During the initialization process we generate some secrets that we'll need +later to use the card: + +* a pairing password needed to pair the card to a device. +* a PIN needed to sign data and transactions (and for other commands). +* a PUK needed to reset the PIN. + +After initialization the card is ready to be paired with a device using the secrets generated in the previous step. + +Once initialized, we can generate a new key with the [GENERATE KEY command](https://status.im/keycard_api/apdu/generatekey.html). +In other cases, it's also possible to import a normal key, an extended key, +or a seed derived from a mnemonic phrase following the [BIP39](https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki). + +Now that we have a master key, we can sign any 32 bytes of data with the derivation path we want +after authenticating with the PIN generated during initialization. + +## The Cash Applet + +