<a href="https:&#x2F;&#x2F;www.philzimmermann.com&#x2F;EN&#x2F;essays&#x2F;WhyIWrotePGP.html" rel="nofollow">https:&#x2F;&#x2F;www.philzimmermann.com&#x2F;EN&#x2F;essays&#x2F;WhyIWrotePGP.html</a><p>&quot;Why I Wrote PGP&quot;, by Philip Zimmermann<p>We really need to emphasize the envelope metaphor a lot more. It&#x27;s much easier for non-technical propel to understand than any discussion of key&#x2F;signing&#x2F;etc.