diff --git a/tests/unit-tests/make-interest-data.hpp b/tests/unit-tests/make-interest-data.hpp
index 36c8deb..8dea8bf 100644
--- a/tests/unit-tests/make-interest-data.hpp
+++ b/tests/unit-tests/make-interest-data.hpp
@@ -81,6 +81,30 @@
 lp::Nack
 makeNack(const Name& name, uint32_t nonce, lp::NackReason reason);
 
+/** \brief replace a name component
+ *  \param[inout] name name
+ *  \param index name component index
+ *  \param a arguments to name::Component constructor
+ */
+template<typename...A>
+void
+setNameComponent(Name& name, ssize_t index, const A& ...a)
+{
+  Name name2 = name.getPrefix(index);
+  name2.append(name::Component(a...));
+  name2.append(name.getSubName(name2.size()));
+  name = name2;
+}
+
+template<typename PKT, typename...A>
+void
+setNameComponent(PKT& pkt, ssize_t index, const A& ...a)
+{
+  Name name = pkt.getName();
+  setNameComponent(name, index, a...);
+  pkt.setName(name);
+}
+
 } // namespace tests
 } // namespace ndn
 
diff --git a/tests/unit-tests/security/command-interest-validator.t.cpp b/tests/unit-tests/security/command-interest-validator.t.cpp
index 6173274..9a9d1e8 100644
--- a/tests/unit-tests/security/command-interest-validator.t.cpp
+++ b/tests/unit-tests/security/command-interest-validator.t.cpp
@@ -112,16 +112,6 @@
   unique_ptr<CommandInterestValidator> validator;
 };
 
-template<typename...A>
-void
-setNameComponent(Name& name, ssize_t index, const A& ...a)
-{
-  Name name2 = name.getPrefix(index);
-  name2.append(name::Component(a...));
-  name2.append(name.getSubName(index + 1));
-  name = name2;
-}
-
 BOOST_AUTO_TEST_SUITE(Security)
 BOOST_FIXTURE_TEST_SUITE(TestCommandInterestValidator, CommandInterestValidatorFixture)
 
@@ -162,57 +152,47 @@
 BOOST_AUTO_TEST_CASE(BadTimestamp)
 {
   auto i1 = makeCommandInterest();
-  Name n1 = i1->getName();
-  setNameComponent(n1, signed_interest::POS_TIMESTAMP, "not-timestamp");
-  i1->setName(n1);
+  setNameComponent(*i1, signed_interest::POS_TIMESTAMP, "not-timestamp");
   assertReject(*i1, CommandInterestValidator::ErrorCode::BAD_TIMESTAMP);
 }
 
 BOOST_AUTO_TEST_CASE(BadSigInfo)
 {
   auto i1 = makeCommandInterest();
-  Name n1 = i1->getName();
-  setNameComponent(n1, signed_interest::POS_SIG_INFO, "not-SignatureInfo");
-  i1->setName(n1);
+  setNameComponent(*i1, signed_interest::POS_SIG_INFO, "not-SignatureInfo");
   assertReject(*i1, CommandInterestValidator::ErrorCode::BAD_SIG_INFO);
 }
 
 BOOST_AUTO_TEST_CASE(MissingKeyLocator)
 {
   auto i1 = makeCommandInterest();
-  Name n1 = i1->getName();
   SignatureInfo sigInfo;
-  setNameComponent(n1, signed_interest::POS_SIG_INFO,
+  setNameComponent(*i1, signed_interest::POS_SIG_INFO,
                    sigInfo.wireEncode().begin(), sigInfo.wireEncode().end());
-  i1->setName(n1);
   assertReject(*i1, CommandInterestValidator::ErrorCode::MISSING_KEY_LOCATOR);
 }
 
 BOOST_AUTO_TEST_CASE(BadKeyLocatorType)
 {
   auto i1 = makeCommandInterest();
-  Name n1 = i1->getName();
   KeyLocator kl;
   kl.setKeyDigest(makeBinaryBlock(tlv::KeyDigest, "\xDD\xDD\xDD\xDD\xDD\xDD\xDD\xDD", 8));
   SignatureInfo sigInfo;
   sigInfo.setKeyLocator(kl);
-  setNameComponent(n1, signed_interest::POS_SIG_INFO,
+  setNameComponent(*i1, signed_interest::POS_SIG_INFO,
                    sigInfo.wireEncode().begin(), sigInfo.wireEncode().end());
-  i1->setName(n1);
   assertReject(*i1, CommandInterestValidator::ErrorCode::BAD_KEY_LOCATOR_TYPE);
 }
 
 BOOST_AUTO_TEST_CASE(BadCertName)
 {
   auto i1 = makeCommandInterest();
-  Name n1 = i1->getName();
   KeyLocator kl;
   kl.setName("/bad/cert/name");
   SignatureInfo sigInfo;
   sigInfo.setKeyLocator(kl);
-  setNameComponent(n1, signed_interest::POS_SIG_INFO,
+  setNameComponent(*i1, signed_interest::POS_SIG_INFO,
                    sigInfo.wireEncode().begin(), sigInfo.wireEncode().end());
-  i1->setName(n1);
   assertReject(*i1, CommandInterestValidator::ErrorCode::BAD_CERT_NAME);
 }
 
@@ -265,12 +245,9 @@
   auto i1 = makeCommandInterest(); // signed at 0s
   assertAccept(*i1);
 
-  auto i2 = makeCommandInterest();
-  Name n1 = i1->getName();
-  Name n2 = i2->getName();
-  setNameComponent(n2, signed_interest::POS_TIMESTAMP,
-                   n1[signed_interest::POS_TIMESTAMP]);
-  i2->setName(n2); // signed at 0s
+  auto i2 = makeCommandInterest(); // signed at 0s
+  setNameComponent(*i2, signed_interest::POS_TIMESTAMP,
+                   i1->getName()[signed_interest::POS_TIMESTAMP]);
   assertReject(*i2, CommandInterestValidator::ErrorCode::TIMESTAMP_REORDER);
 
   advanceClocks(time::seconds(2));
@@ -320,10 +297,8 @@
   auto i1 = makeCommandInterest(1); // signed at 0ms
   auto i2 = makeCommandInterest(2); // signed at 0ms
   for (auto interest : {i1, i2}) {
-    Name name = interest->getName();
-    setNameComponent(name, signed_interest::POS_TIMESTAMP,
+    setNameComponent(*interest, signed_interest::POS_TIMESTAMP,
                      name::Component::fromNumber(time::toUnixTimestamp(time::system_clock::now()).count()));
-    interest->setName(name);
   } // ensure timestamps are exactly 0ms
 
   assertAccept(*i1); // verifying at 0ms
diff --git a/tests/unit-tests/security/validator.t.cpp b/tests/unit-tests/security/validator.t.cpp
index dd2ecd1..8fa26ec 100644
--- a/tests/unit-tests/security/validator.t.cpp
+++ b/tests/unit-tests/security/validator.t.cpp
@@ -21,16 +21,16 @@
 
 #include "security/validator-null.hpp"
 #include "security/key-chain.hpp"
-#include "util/time.hpp"
-#include "identity-management-fixture.hpp"
+
 #include "boost-test.hpp"
+#include "identity-management-fixture.hpp"
+#include "../make-interest-data.hpp"
 
 namespace ndn {
 namespace tests {
 
-using std::string;
-
-BOOST_FIXTURE_TEST_SUITE(SecurityValidator, IdentityManagementFixture)
+BOOST_AUTO_TEST_SUITE(Security)
+BOOST_FIXTURE_TEST_SUITE(TestValidator, IdentityManagementFixture)
 
 void
 onValidated(const shared_ptr<const Data>& data)
@@ -39,7 +39,7 @@
 }
 
 void
-onValidationFailed(const shared_ptr<const Data>& data, const string& failureInfo)
+onValidationFailed(const shared_ptr<const Data>& data, const std::string& failureInfo)
 {
   BOOST_CHECK(false);
 }
@@ -236,7 +236,30 @@
   BOOST_CHECK(Validator::verifySignature(*testInterestRsa, rsaCert->getPublicKeyInfo()));
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_CASE(MalformedInterestSigInfo)
+{
+  auto interest = make_shared<Interest>("/prefix");
+  m_keyChain.sign(*interest);
+
+  setNameComponent(*interest, signed_interest::POS_SIG_INFO, "not-SignatureInfo");
+
+  PublicKey pubkey = m_keyChain.getDefaultCertificate()->getPublicKeyInfo();
+  BOOST_CHECK_EQUAL(Validator::verifySignature(*interest, pubkey), false);
+}
+
+BOOST_AUTO_TEST_CASE(MalformedInterestSigValue)
+{
+  auto interest = make_shared<Interest>("/prefix");
+  m_keyChain.sign(*interest);
+
+  setNameComponent(*interest, signed_interest::POS_SIG_VALUE, "bad-signature-bits");
+
+  PublicKey pubkey = m_keyChain.getDefaultCertificate()->getPublicKeyInfo();
+  BOOST_CHECK_EQUAL(Validator::verifySignature(*interest, pubkey), false);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestValidator
+BOOST_AUTO_TEST_SUITE_END() // Security
 
 } // namespace tests
 } // namespace ndn