diff --git a/ext-hyper/src/hyper_http.rs b/ext-hyper/src/hyper_http.rs
index 20eb8aa..eca4278 100644
--- a/ext-hyper/src/hyper_http.rs
+++ b/ext-hyper/src/hyper_http.rs
@@ -163,7 +163,7 @@ mod tests {
 
   #[tokio::test]
   async fn test_extract_component_from_request() {
-    let mut req = build_request().await.unwrap();
+    let req = build_request().await.unwrap();
 
     let component_id_method = HttpMessageComponentId::try_from("\"@method\"").unwrap();
     let component = extract_http_message_component_from_request(&req, &component_id_method).unwrap();
@@ -186,7 +186,11 @@ mod tests {
       component.to_string(),
       "\"content-digest\": sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:"
     );
+  }
 
+  #[tokio::test]
+  async fn test_extract_signature_params_from_request() {
+    let mut req = build_request().await.unwrap();
     let headers = req.headers_mut();
     headers.insert(
       "signature-input",
@@ -194,6 +198,10 @@ mod tests {
     );
     let component_id = HttpMessageComponentId::try_from("@signature-params").unwrap();
     let component = extract_http_message_component_from_request(&req, &component_id).unwrap();
-    assert_eq!(component.to_string(), "\"@signature-params\": (\"@method\" \"@input\")");
+    assert_eq!(component.to_string(), "\"@signature-params\": (\"@method\" \"@authority\")");
+    assert_eq!(component.value.to_string(), r##"("@method" "@authority")"##);
+    assert_eq!(component.value.as_field_value(), r##"sig1=("@method" "@authority")"##);
+    assert_eq!(component.value.as_component_value(), r##"("@method" "@authority")"##);
+    assert_eq!(component.value.key(), Some("sig1"));
   }
 }
diff --git a/lib/src/message_component/component.rs b/lib/src/message_component/component.rs
index dafb22f..b090bce 100644
--- a/lib/src/message_component/component.rs
+++ b/lib/src/message_component/component.rs
@@ -186,7 +186,7 @@ impl std::fmt::Display for HttpMessageComponentValueInner {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
     match self {
       Self::String(val) => write!(f, "{}", val),
-      Self::KeyValue((key, val)) => write!(f, "{}={}", key, val),
+      Self::KeyValue((_, val)) => write!(f, "{}", val),
     }
   }
 }
@@ -199,8 +199,15 @@ impl HttpMessageComponentValue {
       HttpMessageComponentValueInner::KeyValue((key, _)) => Some(key.as_ref()),
     }
   }
-  /// Get value
-  pub fn value(&self) -> &str {
+  /// Get key value connected with `=`, or just value
+  pub fn as_field_value(&self) -> String {
+    match &self.inner {
+      HttpMessageComponentValueInner::String(val) => val.to_owned(),
+      HttpMessageComponentValueInner::KeyValue((key, val)) => format!("{}={}", key, val),
+    }
+  }
+  /// Get value only
+  pub fn as_component_value(&self) -> &str {
     match &self.inner {
       HttpMessageComponentValueInner::String(val) => val.as_ref(),
       HttpMessageComponentValueInner::KeyValue((_, val)) => val.as_ref(),
@@ -412,6 +419,8 @@ mod tests {
         assert!(!comp.id.params.0.is_empty());
       }
       assert_eq!(comp.value.inner.to_string(), value);
+      assert_eq!(comp.value.as_field_value(), value);
+      assert_eq!(comp.value.key(), None);
       assert_eq!(comp.to_string(), format!("{}: {}", id, value));
     }
   }
@@ -426,7 +435,8 @@ mod tests {
       Some(&HttpMessageComponentParam::Name("key".to_string()))
     );
     assert_eq!(comp.value.inner.to_string(), value);
-    assert_eq!(comp.value.value(), value);
+    assert_eq!(comp.value.as_field_value(), value);
+    assert_eq!(comp.value.key(), None);
     assert_eq!(comp.to_string(), format!("{}: {}", id, value));
   }
 
diff --git a/lib/src/message_component/parse.rs b/lib/src/message_component/parse.rs
index 7919c27..bbfe2ae 100644
--- a/lib/src/message_component/parse.rs
+++ b/lib/src/message_component/parse.rs
@@ -31,15 +31,15 @@ fn build_derived_component(id: &HttpMessageComponentId, field_values: &[String])
     "invalid parameter for derived component"
   );
 
-  let merged = match derived_id {
-    super::DerivedComponentName::Method => field_values[0].to_ascii_uppercase(),
-    super::DerivedComponentName::TargetUri => field_values[0].to_string(),
-    super::DerivedComponentName::Authority => field_values[0].to_ascii_lowercase(),
-    super::DerivedComponentName::Scheme => field_values[0].to_ascii_lowercase(),
-    super::DerivedComponentName::RequestTarget => field_values[0].to_string(),
-    super::DerivedComponentName::Path => field_values[0].to_string(),
-    super::DerivedComponentName::Query => field_values[0].to_string(),
-    super::DerivedComponentName::Status => field_values[0].to_string(),
+  let value = match derived_id {
+    super::DerivedComponentName::Method => HttpMessageComponentValue::from(field_values[0].to_ascii_uppercase().as_ref()),
+    super::DerivedComponentName::TargetUri => HttpMessageComponentValue::from(field_values[0].to_string().as_ref()),
+    super::DerivedComponentName::Authority => HttpMessageComponentValue::from(field_values[0].to_ascii_lowercase().as_ref()),
+    super::DerivedComponentName::Scheme => HttpMessageComponentValue::from(field_values[0].to_ascii_lowercase().as_ref()),
+    super::DerivedComponentName::RequestTarget => HttpMessageComponentValue::from(field_values[0].to_string().as_ref()),
+    super::DerivedComponentName::Path => HttpMessageComponentValue::from(field_values[0].to_string().as_ref()),
+    super::DerivedComponentName::Query => HttpMessageComponentValue::from(field_values[0].to_string().as_ref()),
+    super::DerivedComponentName::Status => HttpMessageComponentValue::from(field_values[0].to_string().as_ref()),
     super::DerivedComponentName::QueryParam => {
       let name = id.params.0.iter().find_map(|p| match p {
         HttpMessageComponentParam::Name(name) => Some(name),
@@ -54,18 +54,17 @@ fn build_derived_component(id: &HttpMessageComponentId, field_values: &[String])
         .filter(|(k, _)| *k == name.as_str())
         .map(|(_, v)| v)
         .collect::<Vec<_>>();
-      kvs.join(", ")
+      HttpMessageComponentValue::from(kvs.join(", ").as_ref())
     }
     super::DerivedComponentName::SignatureParams => {
       let value = field_values[0].to_string();
-      // let s = value.trim().split_once('=');
-      value
+      let opt_pair = value.trim().split_once('=');
+      ensure!(opt_pair.is_some(), "invalid signature-params derived component");
+      let (key, value) = opt_pair.unwrap();
+      HttpMessageComponentValue::from((key, value))
     }
   };
-  let component = HttpMessageComponent {
-    id: id.clone(),
-    value: HttpMessageComponentValue::from(merged.as_ref()),
-  };
+  let component = HttpMessageComponent { id: id.clone(), value };
   Ok(component)
 }