Login to server using putty without password

1. Download and install puttygen using https://www.ssh.com/ssh/putty/windows/puttygen
2. Run puttygen.exe
3. Generate Key Pair

4. Login to the server and paste the public key under /export/home/<user_id>/.ssh/authorized_keys

5. Save the Private Key

6. Open Putty and add the Private Key under Connection -> SSH -> Auth -> Private key file for authentication

7. Enter the username in Putty under Connection -> Data -> Auto-login username

Once the above steps are completed, you should be able to login without any username/password