tarsnap-keygen generates cryptographic keys, registers with the tarsnap server, and writes a key file for use with tarsnap(1).
--keyfile key-file option specifies the name of the file in which to write the newly-generated keys. The
--user user-name option specifies the name (i.e. email address) of the Tarsnap account. The
--machine machine-name option specifies a name which will be displayed in accounting reports so that you can see how much data each machine is storing.
--passphrased option is specified, the user will be prompted to enter a passphrase (twice) to be used to encrypt the key file.
--passphrase-mem maxmem option is specified, a maximum of maxmem bytes of RAM will be used in the scrypt key derivation function to encrypt the key file; it may be necessary to set this option if a key file is being generated on a system with far more RAM than the system on which the key file will be used.
--passphrase-time maxtime option is specified, a maximum of approximately maxtime seconds will be used in the scrypt key derivation function to encrypt the key file.
--version option prints the version number of tarsnap-keygen, then exits.