EROAS

EROAS stands for "Electrum Running On A Stick". It runs Electrum wallet, the best open source bitcoin wallet, on cheap USB drives, with cold-wallet level security and hot-wallet like convenience. It is meant to operate like a saving account for infrequent transactions (perhaps <1 transaction per day). Its strong security level makes it suitable to protect assets over millions of dollars.

Networking modes:

EROAS supports 4 networking modes:

• Connect to Electrum open network directly (default)
• Use Tor to connect to Electrum open network for privacy
• Connect to a designated Electrum server directly for trust/privacy
• Connect to a designated Electrum server via SSH tunnel for trust/privacy (advaned)

Strict firewall rules are imposed.

• No incoming connections
• Outgoing connection is allowed for port 53 (DNS) and optional 80/443 (HTTP/HTTPS).
• Additional outgoing traffic is as allowed based on networking mode
  • For direct connect mode, port 50002 is allowed
  • For Tor mode, port 9001 is allowed
  • For single server mode, connection to the server IP is allowed at Electrum port (50002) or ssh port (22)

Security features

• The system image is an unmutable ISO image, resistent to all persistent attacks.
  • No root user or sudoer in the whole system!
  • Persistent partition is mounted for /home (user data) only
• Electrum data files are stored in a password-protected crypto file system
• Support fingerprint-protected secure drive for additional security
• Strict firewall enforcement
• Use Tor for additional privacy and security
• Support designated electrum server mode
  • You can own a dedicated electrum server easily on AWS
  • Alternatively, you can set up such a server on a raspberry pi 4
• Leverage usual security measures in Electrum wallet (e.g, wallet password)
• Every piece of code is open source and everyone can build from scratch
• Use general purposed and open architecture hardware (PC/Mac/USB disks). No proprietary code or hardware.
• support both Mac and PC

Flash USB drive

• Get a spare USB drive with 2GB or bigger.
  • Backup exiting data as the whole drive will be wiped away.
  • USB 3.0 or above drive is strongly recommended for fast run-time speed.
  • You can also look into fingerprint-protected or keypad protected USB drives for addtional security.
• Download the latest EROAS ISO image
  • Optionally you can build EROAS ISO image yourself relatively easily. See Instructions below.
• Download/install Etcher and use it to flush the ISO image to USB drive.
  • Etcher runs on Mac, Windows and Linux.
  • Windows users can also use rufus. Use all default options and choose "dd" method to do the final flashing.
  • Linux users can simply use dd command (e.g., "sudo dd if=eroas-v0.8.0-20201018-152032.iso of=/dev/sdb bs=4M")
• To flush into fingerprint-protected or keypad-protected secure drive, unlock secure dirve first. Select the secure drive as the flushing target.

Mac users please refer to additional instructions at this link and this link

Use EROAS

• Insert EROAS USB drive into PC/MacBook and boot from USB drive.
  • Different machines have different methods for this step.
  • Refer to a quick guide and a more comprehensive guide
• First time booting up, you may need to set up wifi connection.
  • On the top right corner, click on an icon with 2 arrows to set it up.
• Click on the Electrum launcher icon on Desktop to run Electrum.
  • For the first time running, you will go through a setup process.
• Follow Electrum GUI, set up your wallets, and perform transactions accordingly
• Afterwards shut down the machine and unplug the USB drive.

Note :

• In Tor networking mode, it may take up to 1 or 2 minutes for Electrum to make an initial connection to Electrum network.
• USB drive has an FAT32 "EroasExport" partition, useful for importing/exporting data

Disk partitions

USB drive is divided into 3 partitions

1. EFI partition : ~1GB, FAT32, contains casper rootfs, linux and initrd
2. Home partition : 512MB, ext4, among which 128MB is reserved for Electrum crypto fs
3. Data exchage : the rest of disk, FAT32, for exchanging data with other computers

Build ISO image

• Have a ubuntu 20.04 host
  • other debian-based distro could work, but not tested and may need minor changes
  • no GUI necessary (e.g, AWS ubuntu 20.04 server suffices)
• git clone https://github.com/monkey-jsun/eroas.git
• cd eroas
• ./build_eroas.sh -
• During the build you will be presented a few screens of choices. Always choose the default, except for the followings
  • "Configuring locales" screen #1 : select "end_US ISO-8859-1" and "en_US.UTF-8 UTF-8"
  • "Configuring locales" screen #2 : select "C.UTF-8"

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For donation, Bitcoin wallet address is "bc1qajuwaq620f5s2a4t2dakl9tw0pllj63hw4mqmt"