To log in to other Aspera servers with public key authentication, create key pairs from the command line. Follow the instructions below.
$ mkdir /home/username/.ssh
Go to the .ssh folder and continue:
$ cd user_home_dir\.ssh
$ cd <path-to-user-home-dir>/.ssh
Run the following command in the .ssh folder. The program prompts you for the key-pair's filename. Press ENTER to use the default name id_rsa. For a passphrase, you can either enter a password, or press return twice to leave it blank:
# ssh-keygen -t rsa
When created, the key-pair can be found in your home directory's .ssh folder (assuming you generated the key with the default name id_rsa):
Provide the public key file (for example, id_rsa.pub) to your server administrator, so that it can be set up for your server connection.
Use the option -i private_key_file, instead of -w password, as in the following example:
$ async -N TestBackup -d /tmp/dir -r user@server:/tmp/dir -i PATH_TO_THE_PRIVATE_KEY_FILE