Thank you very much for your help! After hours on this, I finally found that somehow in some manner, my permissions had changed on my home directory  (by something I had done, I guess, that I am still trying to track dwn) and which made the permissions global (for my home directory). Which is not a big deal since I am the only user, but selinux does not like it. So, the problem is fixed now.

Thank you again for your time and looking into it.
 
Best wishes,
Ranjan
 
 
Sent: Monday, September 13, 2021 at 2:39 AM
From: "Samuel Sieb" <samuel@sieb.net>
To: users@lists.fedoraproject.org
Subject: Re: SSH with ecdsa key pair asks for password since yesterday on fully updated F34 setup (both sides)
On 9/12/21 6:12 PM, Ranjan Maitra wrote:
> However, I can no longer do as password-less connection, it worked fine till about 30 hours ago. What could be wrong? Both machines are automatically updated, the one at localhost at 21:00 hours CT (US) and the other (remote server) at 03:00 CT (US) everyday. But the connection did work fine even after the two machines got updated for a while, till around 12:00 yesterday (I can not pinpoint the exact time it last worked).

Check if the config has changed (most likely on the server side). You
say the machines are automatically updated, but are they rebooted after
the update? Assuming they aren't and sshd was updated, then it's hard
to say if or when the updated server or config would come into effect.
Check the dnf history and see if there are any relevant updates recently.
______________________________________________