Enable package signing

Change-Id: Idff4fa85e743fca83bd02f8390087817862a9799
diff --git a/pom.xml b/pom.xml
index a92744f..351cdd3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -109,6 +109,20 @@
                 <artifactId>maven-release-plugin</artifactId>
                 <version>2.5.3</version>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-gpg-plugin</artifactId>
+                <version>1.6</version>
+                <executions>
+                    <execution>
+                        <id>sign-artifacts</id>
+                        <phase>verify</phase>
+                        <goals>
+                            <goal>sign</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>