First, confirm the following basic points.
- Authentification is by using SSH key not by password.
- A private key is pair of a public key registered in a D-way submission account.
- A private key file has read permission.
- A private key file permission is set as others cannot access. For example, rw-------.
- A passphrase for private key is correctly entered.
When transferring data files by using a private key generated in the other operating system, please check format of a private key. Convert private key
In Unix/Mac OS X: Convert a key in the Windows PuTTY file format into the OpenSSH.
In Windows WinSCP: Convert a key in the Unix/Mac OS X OpenSSH file format into the Windows PuTTY format.
When these are correct, because we do not support technical details regarding use of third-party softwares, please refer to websites of softwares or confirm your system administrators whether scp (port 22) is allowed or not.