jcenter { sign }.

src/main/kotlin/com/beust/kobalt/plugin/publish/JCenterApi.kt

@@ -101,20 +101,20 @@ public class JCenterApi @Inject constructor (@Nullable @Assisted("username") val
                     .joinToString("/")
         }
 
-        return upload(files, config, fileToPath, generateMd5 = true, generateAsc = true)
+        return upload(files, config, fileToPath, generateMd5 = true)
     }
 
     fun uploadFile(file: File, url: String, config: JCenterConfig, generateMd5: Boolean = false,
             generateAsc: Boolean = false) =
         upload(arrayListOf(file), config, {
                 f: File -> "${UnauthenticatedJCenterApi.BINTRAY_URL_API_CONTENT}/$username/generic/$url"},
-                generateMd5, generateAsc)
+                generateMd5)
 
     private fun upload(files: List<File>, config: JCenterConfig?, fileToPath: (File) -> String,
-            generateMd5: Boolean = false, generateAsc: Boolean) : TaskResult {
+            generateMd5: Boolean = false) : TaskResult {
         val filesToUpload = arrayListOf<File>()
 
-        if (generateAsc) {
+        if (config != null && config.sign) {
             // Create the .asc files
             filesToUpload.addAll(gpg.runGpg(files))
         }

src/main/kotlin/com/beust/kobalt/plugin/publish/PublishPlugin.kt

@@ -161,7 +161,20 @@ public fun Project.github(init: GithubConfig.() -> Unit) {
 }
 
 data class JCenterConfig(val project: Project) {
+    /**
+     * If true, publish the files to JCenter. If false, the uploaded files will be available only in your
+     * personal bintray maven space
+     */
+    @Directive
     var publish: Boolean = false
+
+    /**
+     * If true, sign the files with GPG. This is only required if you plan to later synchronize these files
+     * from JCenter to Maven Central. Keep this to false if you are only interested in uploading to JCenter.
+     */
+    @Directive
+    var sign: Boolean = false
+
     val files = arrayListOf<Pair<String, String>>()
 
     @Directive