(Edited for accuracy)
I previously posted about Retro-Crypto, a work-in-progress cold wallet and encrypted messaging app for Linux and Nintendo 64. It's developed by bowler-bear based on design specs by me.
Since then, developers have taken it even further with transaction-capable wallets for the PlayStation and Game Boy Color, called PSXX and Off-wallet.
These tools aren't ready for more than testing yet, but this category has huge security advantages. You can't get anything less likely to be backdoored than a vintage game system in your grandma's attic. You can't get anything more air-gapped than transferring data by hand. Most of the security risk can be narrowed down to the ROM itself, trying to ensure you run clean code that isn't malicious or compromised.
Status of each project at time of posting:
Retro-Crypto by Bowler-Bear, for N64 or Linux |
https://github.com/Bowler-Bear/retro-crypto | Working for cold wallet, nostr keygen, and symmetric encryption/decryption, but no outgoing transactions or nevent signing. Has had a forked version made by an additional dev. Still needs more testing and review. Can handle seed phrases and wallet addresses for several coins, including Bitcoin, but only accepts Monero donations.
PSXX by 0xVSultan, for PlayStation |
https://github.com/0xVSultan/PSXX | Needs testing on original hardware. Supports outgoing transactions but not clear on encrypted messaging. Supports and accepts donations in Bitcoin, Monero, doggie coin, and some others.
Off-wallet by elRaulito, for GBC |
https://github.com/elRaulito/Off-wallet | I hear it works for sending and receiving transactions, but is a work-in-progress like the others, not inspected by many eyes yet. Only supports Bitcoin. No wallet listed for donations.
There are a lot of differences between all of these. Retro-Crypto has a CLI-style appearance, PSXX is more game-menu-styled, and Off-wallet simply is an actual game (in fact, it's kind of like Pokemon, which was also created by a Satoshi).
They can all load from SD card adapters but with PSXX that means an array of memory cards, while the others use "flash carts." I think Off-wallet stores keys like a saved game for convenience, while Retro-Crypto deletes keys after use, to keep storage entirely in the user's hands.
The sliding scale between security and convenience will get more interesting in the future, because all of these retro game systems had official peripherals that can help with functions like data transfer. For example, a future version of Retro-Crypto could use a keyboard for input, since the Nintendo 64 had an official keyboard attachment modders are cloning now. The Game Boy had a camera attachment that could be interesting to test for scanning QR codes with such minimal processing power. One of the apps I mentioned even runs on a system that has a suitable hardware feature built-in... those who grew up with that system might know which one I mean.
I'll also mention one other related project that doesn't support Bitcoin, which is SignGB (previously DogeGB) for the Game Boy. It feels worth mentioning because it's almost as old as Retro-Crypto, and the only one other than Retro-Crypto that was already released before the ColdCard hacks. Instead of GitHub, the repo is currently at
https://signgb.app/src/All of these projects still need more peer review before they're ready to be considered the highest-security tools for these purposes. I've helped design and test Retro-Crypto and I'm planning to dig through its code looking for any improvements I can make. If you have one of the original game systems, consider testing. If you're learning any of the coding languages used, consider auditing the code. (These projects are each coded in different languages, except C is in common between all of them)
Follow me on nostr for more news like this: npub1wamvxt2tr50ghu4fdw47ksadnt0p277nv0vfhplmv0n0z3243zyq26u3l2
