PGP signing a message

    % cat sample
    This is a sample.

    This is a sample text file.  I created it with an editor.  If it were
    an actual message, it would contain some useful information.

    This has been a sample.
    % pgp -sat sample
    Pretty Good Privacy(tm) 2.6.2 - Public-key encryption for the masses.
    (c) 1990-1994 Philip Zimmermann, Phil's Pretty Good Software. 11 Oct 94
    Uses the RSAREF(tm) Toolkit, which is copyright RSA Data Security, Inc.
    Distributed by the Massachusetts Institute of Technology.
    Export of this software may be restricted by the U.S. government.
    Current time: 1996/11/09 13:09 GMT

    A secret key is required to make a signature. 
    You specified no user ID to select your secret key,
    so the default user ID and key will be the most recently
    added key on your secret keyring.

    You need a pass phrase to unlock your RSA secret key. 
    Key for user ID "Donald A Watrous <watrous@cs.rutgers.edu>"

    Enter pass phrase:  (does not echo) Pass phrase is good.  
    Key for user ID: Donald A Watrous <watrous@cs.rutgers.edu>
    1024-bit key, Key ID 85082CD5, created 1996/11/09
    Just a moment....
    Clear signature file: sample.asc
    % cat sample.asc
    -----BEGIN PGP SIGNED MESSAGE-----

    This is a sample.

    This is a sample text file.  I created it with an editor.  If it were
    an actual message, it would contain some useful information.

    This has been a sample.

    -----BEGIN PGP SIGNATURE-----
    Version: 2.6.2

    iQCVAwUBMoSCcM4T3nOFCCzVAQFJaAP/eaP2nssHHDTHyPBSjgwyzryguwBd2szF
    U5IFy5JfU+PAa6NV6m/UWW8IKczNX2cmaKQNgubwl3w0odFQPUS+nZ9myo5QtRZh
    DztuhjzJMEzwtm8KTKBnF/LJ9X05pSQUvoHfLZ/waJdVt4E/xfEs90l8DT1HDdIz
    CvynscaD+wA=
    =Xb9n
    -----END PGP SIGNATURE-----
    %