0 to 79 characters. The passphrase is the shared
secret between the sender and the receiver. It is used
to generate the Key Encrypting Key using PBKDF2
(Password-Based Key Derivation Function). It is used
only if &lsquo;<samp>pbkeylen</samp>&rsquo; is non-zero. It is used on
the receiver only if the received data is encrypted.
The configured passphrase cannot be recovered (write-only).
</p>
</dd>
<dt>&lsquo;<samp>pbkeylen=<var>bytes</var></samp>&rsquo;</dt>
<dd><p>Sender encryption key length, in bytes.
Onl