Difference between revisions of "Smart card wallet"

From Bitcoin Wiki
Jump to: navigation, search
(tweak category sort key)
 
(8 intermediate revisions by 5 users not shown)
Line 5: Line 5:
 
*Computers and smartphones are target for malware. The software on a smart card can be protected.
 
*Computers and smartphones are target for malware. The software on a smart card can be protected.
 
*Smart cards do not need a battery, nor internet connection, they are robust.
 
*Smart cards do not need a battery, nor internet connection, they are robust.
*Adoption: people are already used to pay with smart cards.
+
*Adoption: people are already used to paying with smart cards.
  
 
===Desired features===
 
===Desired features===
Line 11: Line 11:
 
*no blockchain, no node; the card contains only private keys, and an algorithm to sign a transaction
 
*no blockchain, no node; the card contains only private keys, and an algorithm to sign a transaction
 
*the smart card should have its own keyboard (for pin code protection) and display (to show the transaction amount)
 
*the smart card should have its own keyboard (for pin code protection) and display (to show the transaction amount)
 +
(<- Alternative to this is the card returning, to the terminal screen, the debit amount multiplied by a number only the card holder knows which cycles from 1 to 100 to 1 incrementing by 1 each transfer - the card is locked 10 minutes if a second amount is send before a pin is typed.)
 +
* The card holder will know pin, puk, private key and address only from when he programmed it or ordered his smart card.
 
*the card should implement a deterministic wallet, so that funds can be recovered if the card is lost.
 
*the card should implement a deterministic wallet, so that funds can be recovered if the card is lost.
  
Line 34: Line 36:
 
*this lightweight wallet will be later implemented on the card  
 
*this lightweight wallet will be later implemented on the card  
 
*use it to define the communication protocol between card and reading device.
 
*use it to define the communication protocol between card and reading device.
 +
 +
update: this is done, see [[Electrum]]
  
 
===3. implement wallet on a simple smart card===
 
===3. implement wallet on a simple smart card===
Line 40: Line 44:
 
* amadousarr.free.fr/crypto/ECDSAJAVACARD.pdf : A Software Implementation of ECDSA on a Java Smart Card
 
* amadousarr.free.fr/crypto/ECDSAJAVACARD.pdf : A Software Implementation of ECDSA on a Java Smart Card
 
* http://www.acs.com.hk : cards, readers, development kits; no display, pincode needs to be typed on the reading device
 
* http://www.acs.com.hk : cards, readers, development kits; no display, pincode needs to be typed on the reading device
 +
* http://www.basiccard.com/index.html?overview.htm : Smart Card (ZC7.5) which contains RSA/EC and DES/AES coprocessors. Used in an implementation of the OpenPGP Card 2.0 standard (http://g10code.com/p-card.html)
  
 
===4. implement wallet on a smart card with display and pincode ===
 
===4. implement wallet on a smart card with display and pincode ===
Line 56: Line 61:
 
[[category:Developer]]
 
[[category:Developer]]
 
[[category:Technical]]
 
[[category:Technical]]
[[category:Wallets]]
+
[[category:Wallets| ]]
 +
[[Category:Mobile]]

Latest revision as of 08:18, 22 May 2018

This pages gathers resources for the implementation of a Bitcoin wallet on a smart card.

Rationale

  • Computers and smartphones are target for malware. The software on a smart card can be protected.
  • Smart cards do not need a battery, nor internet connection, they are robust.
  • Adoption: people are already used to paying with smart cards.

Desired features

  • no blockchain, no node; the card contains only private keys, and an algorithm to sign a transaction
  • the smart card should have its own keyboard (for pin code protection) and display (to show the transaction amount)

(<- Alternative to this is the card returning, to the terminal screen, the debit amount multiplied by a number only the card holder knows which cycles from 1 to 100 to 1 incrementing by 1 each transfer - the card is locked 10 minutes if a second amount is send before a pin is typed.)

  • The card holder will know pin, puk, private key and address only from when he programmed it or ordered his smart card.
  • the card should implement a deterministic wallet, so that funds can be recovered if the card is lost.

Usage scenario

  • the reading device may belong to a merchant at a point of sale; it cannot be trusted with private keys.
  • the reading device is connected to a full bitcoin node; it can be trusted for getting and sending blockchain information.
  • the reading device sends to the card the current balance of its bitcoin addresses. This information can be cached in the card.
  • the reading device sends a bitcoin receiving address and transaction amount to the card.
  • the amount is displayed by the card ; the user confirms the transaction with his pin code.
  • the smart card creates a signed transaction and sends it to the reading device
  • the transaction is checked and broadcast by the bitcoin node.

Implementation steps

1. write a bitcoin daemon that can talk to a lightweight wallet

2. write a lightweight wallet

  • wallet without blockchain, in order to test the daemon
  • this lightweight wallet will be later implemented on the card
  • use it to define the communication protocol between card and reading device.

update: this is done, see Electrum

3. implement wallet on a simple smart card

4. implement wallet on a smart card with display and pincode

list of vendors:


references