diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/EventExt.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/EventExt.kt
index 11ceb0b5aa..62fe0ab620 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/EventExt.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/EventExt.kt
@@ -22,6 +22,4 @@ package com.vitorpamplona.quartz.nip70ProtectedEvts
 
 import com.vitorpamplona.quartz.nip01Core.core.Event
 
-const val PROTECTED_TAG = "-"
-
-fun Event.isProtected() = tags.any { (it.size > 0 && it[0] == PROTECTED_TAG) }
+fun Event.isProtected() = tags.isProtected()
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayBuilderExt.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayBuilderExt.kt
new file mode 100644
index 0000000000..3f820f5538
--- /dev/null
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayBuilderExt.kt
@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip70ProtectedEvts
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip70ProtectedEvts.tags.ProtectedTag
+
+fun <T : Event> TagArrayBuilder<T>.protect() = addUnique(ProtectedTag.assemble())
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayExt.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayExt.kt
new file mode 100644
index 0000000000..27260e8b1e
--- /dev/null
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/TagArrayExt.kt
@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip70ProtectedEvts
+
+import com.vitorpamplona.quartz.nip01Core.core.TagArray
+import com.vitorpamplona.quartz.nip70ProtectedEvts.tags.ProtectedTag
+
+fun TagArray.isProtected() = any(ProtectedTag::match)
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/tags/ProtectedTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/tags/ProtectedTag.kt
new file mode 100644
index 0000000000..c9027d9dcb
--- /dev/null
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip70ProtectedEvts/tags/ProtectedTag.kt
@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip70ProtectedEvts.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+class ProtectedTag {
+    companion object {
+        const val TAG_NAME = "-"
+
+        @JvmStatic
+        fun match(tag: Array<String>): Boolean {
+            ensure(tag.has(0)) { return false }
+            ensure(tag[0] == TAG_NAME) { return false }
+            return true
+        }
+
+        @JvmStatic
+        fun parse(tag: Array<String>): Boolean? {
+            ensure(tag.has(0)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            return true
+        }
+
+        @JvmStatic
+        fun assemble() = arrayOf(TAG_NAME)
+    }
+}