Maybe a feature for key password storage can be added in the future :), even if it can pose a security risk.

Pageant is a solution, but it require to enter the key password at each reboot.

The problem is now solved by using a private key without password.

Thank you.

There was a bug in some older versions of WinSCP, that made it using stored password as key passphrase. That was not intentional.

The bug was fixed.

See also https://winscp.net/eng/docs/faq_passphrase

Yesterday I've updated my old Winscp (5.5.1) to the latest stable version (5.9.6-Portable) deleting old ini file and creating new connection profiles from scratch.

The problem I noticed is that while with the previous version the private key password was stored and never asked when connecting to a server, now I have to enter the key password each time I establish a connection.

If I uncheck "Tools > Preferences > Security > Session password > Remember password for duration of session" option, an option to remember the key password is shown when connecting, but it's ignored each time I connect again.

Any suggestion for this issue is welcomed.