title: PGP TarBall File Signature Keys Verification fails with no valid OpenPGP data found
body: <p>This is the first time I figured I had better check the keys of the bind software I want to install.  So I downloaded what I think is a OpenPGP key ...</p>
  
  <pre><code>$ wget ftp://ftp.isc.org/isc/bind9/9.9.4/bind-9.9.4.tar.gz.sha1.asc
  </code></pre>
  
  <p>... then I tried to "import" this key like this ...</p>
  
  <pre><code>$ gpg --import bind-9.9.4.tar.gz.sha1.asc
  </code></pre>
  
  <p>... but I get this error message:</p>
  
  <pre><code>gpg: no valid OpenPGP data found.
  gpg: Total number processed: 0
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>Thanks!</p>