Exploring Bitcoin Pre-0.4 Encryption Techniques

So in bitcoin 0.4, it started using private key encryption... but did any of the wallets like multibit or BitcoinJ (pre-0.4) utilize the same method? I read somewhere they both use AES, but I’m struggling to find the info in the BitcoinJ Google group.

Interesting topic, I gotta say. Bitcoin 0.4 did bring in AES-256-CBC while handling private keys differently. They used double SHA256 for IV. Around 2011, both BitcoinJ and Multibit were on AES too, only not in the same way since core relied on OpenSSL while BitcoinJ was Java-based. The characters you mentioned do kinda fit the core wallet's dumps from back then.

Yeah, I heard that as well. Multibit up to version 0.3.x and bitcoinj 0.5 used similar encryption methods for private keys. Thought it was OpenSSL too, but honestly, I’m no programmer, just a kid who started on a Commodore ages ago.

You mentioned repositories? I peeked at those, it’s funny you don’t see yourself as a programmer. The decrypt scripts you found are meant for BIP39 wallets. They mirror the wallet encryption logic in BitcoinJ. The recovery utility is more for MultiBit wallet files.

I tried to run some code, but nothing clicked. I just have those 34 and 16 character strings noted. That seemed sufficient for bitcoin 0.3.24... When I base64 hex the secret key it shows me some results but unsure where to go from here.

Here's the lowdown: before 0.4.0, Core didn’t have wallet encryption. Previous versions stored keys unencrypted. Bitcoin Core 0.4+ introduced encryption with a random master key and specific methods for deriving the passphrase. So all that basic stuff you’re digging into is definitely pre-0.4.