Learn how to build a cryptocurrency hardware wallet using the Go programming language, Angular, and a Raspberry Pi Zero.

1. Building a Bitcoin Hardware
Wallet with Golang and a
Raspberry Pi Zero
Nic Raboy | @nraboy
Tracy Developer Meetup Organizer

2. Disclaimer
I am not an expert in cryptocurrency and encryption.

3. Agenda
1. A Background on the Various Bitcoin Wallets
2. What is the Raspberry Pi Zero
3. Open Ledger Micro Demo
4. Interacting with Bitcoin with the Go Programming Language
5. Understanding the Risks and Limitations

4. A Background on the Various
Bitcoin Wallets

5. Exchange Wallets
● Coinbase, Binance, Kraken, etc.
● Conveniently managed by a third party.
● As secure as the exchange.
○ Mt.Gox, Bitfinex, Coincheck, etc.
● The exchange is in control of any and all currency.

6. Software Wallets
● Exodus, Electrum, Bitcoin Core, etc.
● You control your cryptocurrency data.
● Risk of a malicious remote attack is decreased.
● As secure as your computer.
● Risk of malware attacks.
● Risk of hard disk failure.

7. Paper Wallets
● QR Codes, Plaintext, Barcodes, etc.
● Cyberattacks are eliminated.
● Risk of elemental damage such as fire.
● Risk of theft from burglary.

8. Hardware Wallets
● Ledger Nano S, Trezor, etc.
● Encrypted and disconnected from the internet.
● Accessible from a single host machine at any
given time.

9. What is the Raspberry Pi Zero

10. Raspberry Pi and Raspberry Pi Zero

11. Raspberry Pi 3 - $35.00
● 1.4 GHz Quad-Core CPU
● 1 GB RAM
● WiFi and BLE
● HDMI
● 4x USB
● Gigabit Ethernet

12. Raspberry Pi Zero - $5.00
● 1 GHz Single-Core CPU
● 512 MB RAM
● Mini HDMI
● Micro USB On-the-Go (OTG)

13. Linux Distributions

14. Open Ledger Micro Demo

15. Interacting with Bitcoin with the
Go Programming Language

16. The Go Programming Language
● Create dependency free application binaries.
● Cross-compile to nearly any CPU architecture and operating system.
● Great for networking and concurrency.
● In-demand programming language.
● Mild learning curve.

17. Project Dependencies
● github.com/GeertJohan/go.rice
● github.com/gorilla/mux
● github.com/btcsuite/btcutil
● github.com/btcsuite/btcd

18. Exposed API Functions

19. High Level Plan
● Must create an encrypted database file.
● Must be able to decrypt a database file.
● Must be able to add coin data to a database file.
● Must be able to generate signed transactions.

20. Data Structures

21. Define Network Information

22. Generate Private Keys and Public Addresses

23. Import Private Keys

24. Encrypt and Decrypt Binary Data

25. Encrypt and Decrypt Files

26. Import Coin Into Wallet

27. Get Addresses without Private Keys

28. Transactions

29. Create Source Transaction

30. Create Redeeming Transaction

31. Create Wallet API Endpoint

32. Create Coin API Endpoint

33. Import Coin API Endpoint

34. Get Addresses API Endpoint

35. Create Transaction API Endpoint

36. Understanding the Risks and
Limitations

37. Risks and Limitations
1. Wallet password can be brute forced from host machine
2. Passwords can be compromised from malware on host machine
3. Hard disk corruption or failure on the Raspberry Pi Zero

38. Possible Solutions
1. Set retry timeout or wipe Raspberry Pi Zero after X failed attempts
2. Hardware buttons
3. Airgap with QR codes and cameras
4. Backups

39. What’s Next?

40. Tutorial and Code
In-Depth Tutorial:
https://www.thepolyglotdeveloper.com/2018/03/create-bitcoin-hardware-wallet-
golang-raspberry-pi-zero/
Source Code:
https://github.com/nraboy/open-ledger-micro

41. More Help
Twitter:
https://www.twitter.com/nraboy
Blog:
https://www.thepolyglotdeveloper.com
YouTube:
https://www.youtube.com/user/nicraboy/videos