Make the Smartcard great again

Bitcoin MilanoNovember 2016

Nicolas Bacca @btchip

A trust layer between the blockchain and the physical world

For industrials, enterprises and consumers

Securing the first and last mile

LEDGER TECHNOLOGY

Without trust, data has no actionable value

node

node

node

node

nodeCloud servers

User on a PC or a smartphone Industrial

sensor / IoT

node

node node

Connected object

Blockchain/ITtrusted zone

Physical worldabsence of trust

Is this really you?

Am I allowed to execute this transaction?

Critical temperature data

Did the driver got switched?

Why ? Cryptocurrencies come with built-in bug bounties

#SFYL

CO 2.0

(Etienne Daho, theoretical singer, so it makesa good joke, at least in french)

The Smartcard is great

Best technical solution for at scale (CHEAP) secure deployment (see SIM cards)

Best technical solution against physical attacks (theft, evil maid)

Lot of resources invested in secure remote management

Great portability of Java Card, at least on paper

The Smartcard is not so great

Absolutely not made for the web, or use in an untrusted terminal, or any user

Not really open to developers (Java Card is the best try)

Totally not auditable (NDA’ed chips, closed operating systems)

Making the Smartcard great again

Build on top of the great things

Change the problems

Why using MCUs for security applications is a bad idea

No protection against physical attacks

No dedicated chip delivery means no traceability : no attestation, no endorsement

Side effect : you can’t tell which firmware version the device is actually running

Price can’t scale in volume

Acceptable use case : DIY for hobbyists, assembled and flashed by you

Our latest consumer devices

Ledger Nano S : available now

Ledger Blue : end 2016(larger screen, BLE)

Hardware Oracle - for machines

Cryptographically attestable anti-tampering sensors

￭ Secure chip ST31G480 (CC EAL6+)￭ Sensor￭ 3 axis anti-tampering MEMS￭ USB interface for blockchain computer

Ledger platform architecture

Trusted / Secure component (Secure Element or enclave) with limited I/O options

Non trusted component with more I/O options

Screen

Direct control from the Trusted component, proxied

Pairing at boot time

User app 1

User app 2

Button

Sensor

USB

GlobalPlatform / Java Card isolation

Improving on isolation, using ARM capabilities

Native application 1

Native application 2

Native application 3

MicrokernelUserseed

MMU lock

User modeSupervisor mode

System call

UI application

Device authentication

Host or remote server Ledger dashboard

Get device keys

Ephermeral key, signed by device key, signed by root of trust

Send public key

ECDH secret used as an AES key

Encrypted data exchange

A secure app store model

Install applications on demand

Allows private data / applications, regarding provisioning or secrets

Master seed derivation path can be locked per application, preventing escalation

Bitcoin Ethereum OpenPGP U2F

44’/0’ 44’/61’ 13’ or 17’ 5583430’

Discardable applications

New use case created by the app store

Secure Element space is limited : remove non frequently used applications

Typical targets : paper wallet sweepers

Security summary

SE authenticates MCU, hashing its full flash

Applications are authenticated at launch (prompt if unsigned)

Special UI application is authenticated at boot time (prompt if unsigned)

Applications interact with user data through kernel APIs

Seed derivation parameters can be locked in per application

Kernel can be open sourced in several stageshttps://blog.ledger.co/secure-hardware-and-open-source-ecd26579d839

Portability

C source code

Secure ElementARM cross compiler

Ledger secure application

Secure enclave or HSM

Moxie cross compiler

Nano S, Blue

Hardware Oracle

HSM

TEE, SGX

Handling an untrusted host

Display information on screen

Request user presence for all sensitive operations

Use specific applications to make generic information understandable

Example : ETC/ETH split https://blog.ledger.co/splitting-your-ethers-securely-on-your-nano-s-147f20e9e341

Building a Plug and Play device

Generic HID interface - no driver required

Unfortunately USB support in web browsers is not yet standardized

Worse the best support (Chrome applications) is getting phased out

Following a long line of failures (ActiveX, Java applets, browser plugins)

Looking for a replacement ideally requiring nothing to install

U2F standard (FIDO Alliance)

2FA mechanism backed by cryptographic hardware, pushed into modern browsers

Send nonce, application ID

Generate keypair

Send public key, encrypted private key (keyhandle)

Send nonce, application ID, encrypted private key (keyhandle)

Send nonce signature

Registration

Authentication

A little twist on U2F authentication

Send nonce, application ID, encrypted private key (keyhandle)

Send nonce signature

Command

Response

Tested on MyEtherWallet

Bitcoin implementation coming soon

Getting started with development

Nano-S resources : compiler and SDK - https://github.com/ledgerhq/ledger-nano-s

Sample applications : https://github.com/LedgerHQ/blue-sample-apps

Documentation in progress : http://ledger.readthedocs.io/

Developer Slack : http://slack.ledger.co

Documentation is getting put together, so don’t hesitate to ask on Slack

Bitcoin wallet

https://github.com/LedgerHQ/blue-app-btc

Integrated with GreenAddress / GreenBits, Copay, Electrum, Mycelium

Base code to create additional Bitcoin applications

Hardware Oracle reporting a Colored asset

Hot Wallet applying quotas on third party accounts

Ethereum wallet

https://github.com/LedgerHQ/blue-app-eth

Integrated with MyEtherWallet (pilot modified U2F transport)

Base code to create specific smart contract logic

ETH/ETC split

SSH / PGP agent

https://github.com/LedgerHQ/blue-app-ssh-agent

SSH authentication, PGP signature / decryption

Minimalistic application, compatible with https://github.com/romanz/trezor-agent

To be phased out by the OpenPGP application adding external keys support, RSA

U2F client

https://github.com/LedgerHQ/blue-app-u2f

U2F client implementation

Base code to create mixed U2F transports

UI interface

https://github.com/LedgerHQ/nanos-ui

Base UI interface (privileged application)

Can be used to create new dashboards, enrollment methods, PIN mechanisms

Electrum seed support

Coming soon (™)

Standalone Password Manager (typing passwords as a keyboard)

OpenPGP card application (RSA, CCID support)

Bitcoin wallet integration in the browser with no third party applications

Readable ERC-20 tokens support for ETH

Thank you @btchip