README.md in usps_flags-grades-0.0.7 vs README.md in usps_flags-grades-0.0.8

@@ -19,9 +19,26 @@
 end
 
 insignia.svg #=> Generates SVG file at "/path/to/svg/output.svg"
 ```
 
+## Security
+
+This gem is cryptographically signed. To be sure the gem code hasn’t been
+tampered with:
+
+Add my public key as a trusted certificate:
+
+```sh
+gem cert --add <(curl -Ls https://raw.github.com/jfiander/usps-flags_grades/master/certs/jfiander.pem)
+```
+
+Then install the gem securely:
+
+```sh
+gem install usps_flags-grades -P HighSecurity
+```
+
 ## License
 
 Actual images generated are
 [registered trademarks](http://www.usps.org/national/itcom/trademark.html) of
 United States Power Squadrons.