🦀 Bitcoin Address Generator (From Scratch)

A minimalist command-line tool written in Rust that generates a Bitcoin Private Key and derives its corresponding Legacy Address (P2PKH).

Why this exists: This project was built as a study exercise. Instead of using the standard rust-bitcoin library, I implemented the protocol logic manually using primitive cryptographic libraries (k256, sha2, ripemd) to deeply understand the mathematical pipeline of Bitcoin identities.

---

🚀 Features

• Entropy Generation: Uses OS-level randomness (OsRng) to generate secure 256-bit secrets.
• Elliptic Curve Math: Manually derives Compressed Public Keys using the secp256k1 curve.
• Hashing Pipeline: Implements the Hash160 standard (SHA-256 followed by RIPEMD-160).
• Checksum Validation: Calculates the double-SHA256 checksum to prevent typing errors.
• Base58 Encoding: Converts the raw byte payload into the standard Bitcoin address format.

---

🛠️ Tech Stack

• Language: Rust 🦀
• Elliptic Curves: k256 (Pure Rust implementation of secp256k1)
• Hashing: sha2, ripemd
• Encoding: bs58, hex

---

📚 How It Works (The Pipeline)

The code follows the standard Bitcoin address generation steps:

1. Generate Private Key: $k$ (256-bit integer)
2. Derive Public Key: $K = k \times G$ (Elliptic Curve Multiplication)
3. Hash160: $H = \text{RIPEMD160}(\text{SHA256}(K))$
4. Add Version Byte: Prepend 0x00 (Mainnet)
5. Checksum: Take first 4 bytes of $\text{SHA256}(\text{SHA256}(\text{Version} + H))$
6. Encode: Base58 encode the result.

---