diff --git a/tests/test-class-activitypub-rest-post-signature-verification.php b/tests/test-class-activitypub-rest-post-signature-verification.php
new file mode 100644
index 0000000..f972871
--- /dev/null
+++ b/tests/test-class-activitypub-rest-post-signature-verification.php
@@ -0,0 +1,57 @@
+<?php
+
+class Test_Activitypub_Rest_Post_Signature_Verification extends WP_UnitTestCase {
+
+	public function test_activity_signature() {
+
+		$pre_http_request = new MockAction();
+		add_filter( 'pre_http_request', array( $pre_http_request, 'filter' ), 10, 3 );
+
+		// Activity for generate_digest
+		$post = \wp_insert_post(
+			array(
+				'post_author' => 1,
+				'post_content' => 'hello world',
+			)
+		);
+		$remote_actor = \get_author_posts_url( 2 );
+		$activitypub_post = new \Activitypub\Model\Post( $post );
+		$activitypub_activity = new Activitypub\Model\Activity( 'Create' );
+		$activitypub_activity->from_post( $activitypub_post );
+		$activitypub_activity->add_cc( $remote_actor );
+		$activity = $activitypub_activity->to_json();
+
+		// generate_digest & generate_signature
+		$digest = Activitypub\Signature::generate_digest( $activity );
+		$date = gmdate( 'D, d M Y H:i:s T' );
+		$signature = Activitypub\Signature::generate_signature( 1, 'POST', $remote_actor, $date, $digest );
+
+		//  Signed headers
+		$url_parts = wp_parse_url( $remote_actor );
+		$route = $url_parts['path'] . '?' . $url_parts['query'];
+		$host = $url_parts['host'];
+
+		$headers = array(
+			'digest' => [ "SHA-256=$digest" ],
+			'signature' => [ $signature ],
+			'date' => [ $date ],
+			'host' => [ $host ],
+			'(request-target)' =>  [ 'POST ' . $route ]
+		);
+
+		// Start verification
+		// parse_signature_header, get_signed_data, get_public_key
+		$signature_block = Activitypub\Signature::parse_signature_header( $headers['signature'] );
+		$signed_headers = $signature_block['headers'];
+		$signed_data = Activitypub\Signature::get_signed_data( $signed_headers, $signature_block, $headers );
+		$public_key = Activitypub\Signature::get_public_key( 1 );
+
+		// signature_verification
+		$verified = \openssl_verify( $signed_data, $signature_block['signature'], $public_key, 'rsa-sha256' ) > 0;
+		$this->assertTRUE( $verified );
+
+		remove_filter( 'pre_http_request', array( $pre_http_request, 'filter' ), 10 );
+	}
+
+
+}