Designed and developed a secure Bitcoin wallet application using Python, supporting both single-signature (single-sig)and multi-signature (multi-sig) addresses. Key features include:

• Mnemonic phrase generation & recovery (BIP-39)
• HD key derivation (BIP-32/BIP-44) with a tree structure for organized wallet paths
• Transaction creation and signing
• Balance checking and address management
• QR code support for easy payments
• Fully offline-capable for cold storage and maximum security

Built with a user-friendly interface and designed for both beginners and advanced crypto users. The wallet emphasizes privacy, control, and transparency, without relying on third-party custodians.