Thank you for the response. I have been researching the forum and old discussions, but what I am specifically looking for is a method that might have been used by early users to generate private keys using a combination of a string, passphrase, and salt.
For example, was there any known practice of using OpenSSL commands like HMAC, PBKDF2, or direct hashing methods (e.g., SHA-256, SHA-512) to derive a private key deterministically?
I am particularly interested in whether any early Bitcoin users might have used a repeatable process, similar to how deterministic wallets work today, but manually, without HD wallets.
If anyone has insights, examples, or can point me to discussions covering this topic, I would appreciate it.
We could discuss the following questions:
1. Was it possible to generate private keys using OpenSSL in Bitcoin’s early days?
Yes. In fact older version of Bitcoin Core (back then it was called "Bitcoin" and "Bitcoin-Qt") had OpenSSL dependency.
5. Are there any previous discussions on Bitcointalk regarding deterministic private key generation in Bitcoin’s early days?
Yes, here's an example
Deterministic wallets. You can use
https://ninjastic.space/search to find other relevant discussion topic.