SFTP Software Development for Windows

I need a skilled developer or agency to build SFTP software for secure file transfers across 6 locations on Windows. This is a one-time project with a 1-year support commitment.

Important note: please have a look at the attached image.

Required Features:
- SSH File Transfer Protocol (SFTP) implementation
- Windows compatibility
- TLS 1.3 support for FTPS/S HTTPS transfers
- SFTP cipher, MAC & KEX control
- Support for Elliptic-curve Diffie-Hellman (ECDH) key exchanges
- Authentication: Password and/or public key-based
- IP access manager to blacklist/whitelist IPs
- Minimum 1-year data storage capacity

Additional Requirements:
- 1-year warranty with 24x7 free support
- Clean, secure, and efficient code delivery
- Clear documentation and deployment assistance

Ideal Skills & Experience:
- Expertise in developing SFTP solutions
- Strong knowledge of encryption algorithms, especially AES
- Experience with IP access control mechanisms
- Proficiency in Windows software development
- Good documentation skills

Looking forward to your proposals!