c64wallet - Commodore 64 Bitcoin Wallet

[mcrypto1984]

Hi

I created c64wallet - Commodore 64 Bitcoin Wallet.

It works as offline wallet (standard c64 doesn't have access to internet) and provides basic functionality:

• Creating new bitcoin wallet
• Saving/loading wallet from tape/disk (with encryption)
• Displaying address wih QR code (only bech32 segwit addresses are supported)
• Displaying privete key with QR code (WIF format)
• Displaying public key in hex format

https://github.com/geek197/c64wallet

One screen from main menu:
https://raw.githubusercontent.com/geek197/c64wallet/refs/heads/master/screens/c64wallet.png

Because C64 has very slow CPU (compared to current CPUs) generating key pair takes around 30 minutes. But it works!
It's just fun project. Try store you paper wallets in 80-s way but don't expect too much  

[cygan]

Hi

I created c64wallet - Commodore 64 Bitcoin Wallet.
✂️

hello... i think it’s really interesting and kind of funny to name a Bitcoin wallet that way
i used to have a c128 myself, which was equipped with a floppy drive and a dataset - those were really good times back then...
and im curious to see how this Bitcoin wallet develops… i’m guessing it’ll only be available as a desktop version, right?

btw maybe you should change the text background color from yellow to Bitcoin orange

[ABCbits]

I never use Commodore 64 in my whole life. But after i skimmed your code, do you use entropy from user keyboard input because Commodore 64 (whether real or emulated) doesn't provide OS/hardware level secure RNG?

[NotATether]

Interesting.

When you say generating a keypair takes 30 minutes, are you referring to private key -> pubic key calculation, or are you referring to PBKDF derivation of private keys from seed phrases, or both?

Though I wouldn't be surprised if it was ECC itself that's slow, considering that the C64 cpu and other really old CPUs like the i386 were made in a different era before most transistor optimization techniques were known/used.

[mcrypto1984]

I never use Commodore 64 in my whole life. But after i skimmed your code, do you use entropy from user keyboard input because Commodore 64 (whether real or emulated) doesn't provide OS/hardware level secure RNG?

There is something similar to hardware random generator using SID (sound device subsystem in c64) but I'm not sure if this realy random. So I decided to use user input. Maybe I investigate this topic deeper in future.

[mcrypto1984]

Interesting.

When you say generating a keypair takes 30 minutes, are you referring to private key -> pubic key calculation, or are you referring to PBKDF derivation of private keys from seed phrases, or both?

Though I wouldn't be surprised if it was ECC itself that's slow, considering that the C64 cpu and other really old CPUs like the i386 were made in a different era before most transistor optimization techniques were known/used.

Yes, private->public keys computation (ECC) takes around 30 minutes. Standard PBKDFs, like iterations of sha256 are also painfuly slow, so I decided to use custom solution where ratio (modern cpu speed / c64 cpu speed) is lowest. Iternaly it uses RC4 which is pure 8-bit algorithm. It's not secure for encryption anymore but I think for PBKDF is still good enough.

[mcrypto1984]

Hi

I created c64wallet - Commodore 64 Bitcoin Wallet.
✂️

hello... i think it’s really interesting and kind of funny to name a Bitcoin wallet that way
i used to have a c128 myself, which was equipped with a floppy drive and a dataset - those were really good times back then...
and im curious to see how this Bitcoin wallet develops… i’m guessing it’ll only be available as a desktop version, right?

btw maybe you should change the text background color from yellow to Bitcoin orange

Currently there is only version for real c64 computer (or emulator) + command line version for testing/development purposes.