diff --git a/src/data.cpp b/src/data.cpp
index 6b50dca..090b82d 100644
--- a/src/data.cpp
+++ b/src/data.cpp
@@ -49,8 +49,8 @@
 {
   // Data ::= DATA-TLV TLV-LENGTH
   //            Name
-  //            MetaInfo
-  //            Content
+  //            MetaInfo?
+  //            Content?
   //            SignatureInfo
   //            SignatureValue
 
@@ -121,26 +121,75 @@
 void
 Data::wireDecode(const Block& wire)
 {
-  m_fullName.clear();
   m_wire = wire;
   m_wire.parse();
+  bool hasName = false, hasSigInfo = false;
+  m_name.clear();
+  m_metaInfo = MetaInfo();
+  m_content = Block(tlv::Content);
+  m_signature = Signature();
+  m_fullName.clear();
 
-  // Name
-  m_name.wireDecode(m_wire.get(tlv::Name));
+  int lastEle = 0; // last recognized element index, in spec order
+  for (const Block& ele : m_wire.elements()) {
+    switch (ele.type()) {
+      case tlv::Name: {
+        if (lastEle >= 1) {
+          BOOST_THROW_EXCEPTION(Error("Name element is out of order"));
+        }
+        hasName = true;
+        m_name.wireDecode(ele);
+        lastEle = 1;
+        break;
+      }
+      case tlv::MetaInfo: {
+        if (lastEle >= 2) {
+          BOOST_THROW_EXCEPTION(Error("MetaInfo element is out of order"));
+        }
+        m_metaInfo.wireDecode(ele);
+        lastEle = 2;
+        break;
+      }
+      case tlv::Content: {
+        if (lastEle >= 3) {
+          BOOST_THROW_EXCEPTION(Error("Content element is out of order"));
+        }
+        m_content = ele;
+        lastEle = 3;
+        break;
+      }
+      case tlv::SignatureInfo: {
+        if (lastEle >= 4) {
+          BOOST_THROW_EXCEPTION(Error("SignatureInfo element is out of order"));
+        }
+        hasSigInfo = true;
+        m_signature.setInfo(ele);
+        lastEle = 4;
+        break;
+      }
+      case tlv::SignatureValue: {
+        if (lastEle >= 5) {
+          BOOST_THROW_EXCEPTION(Error("SignatureValue element is out of order"));
+        }
+        m_signature.setValue(ele);
+        lastEle = 5;
+        break;
+      }
+      default: {
+        if (tlv::isCriticalType(ele.type())) {
+          BOOST_THROW_EXCEPTION(Error("unrecognized element of critical type " +
+                                      to_string(ele.type())));
+        }
+        break;
+      }
+    }
+  }
 
-  // MetaInfo
-  m_metaInfo.wireDecode(m_wire.get(tlv::MetaInfo));
-
-  // Content
-  m_content = m_wire.get(tlv::Content);
-
-  // SignatureInfo
-  m_signature.setInfo(m_wire.get(tlv::SignatureInfo));
-
-  // SignatureValue
-  Block::element_const_iterator val = m_wire.find(tlv::SignatureValue);
-  if (val != m_wire.elements_end()) {
-    m_signature.setValue(*val);
+  if (!hasName) {
+    BOOST_THROW_EXCEPTION(Error("Name element is missing"));
+  }
+  if (!hasSigInfo) {
+    BOOST_THROW_EXCEPTION(Error("SignatureInfo element is missing"));
   }
 }
 
diff --git a/src/data.hpp b/src/data.hpp
index 8eb1b3d..2368017 100644
--- a/src/data.hpp
+++ b/src/data.hpp
@@ -45,21 +45,23 @@
     }
   };
 
-  /** @brief Create a new Data with the given name and empty Content
-   *  @warning In certain contexts that use Data::shared_from_this(), Data must be created
-   *           using `make_shared`. Otherwise, .shared_from_this() will trigger undefined behavior.
+  /** @brief Construct an unsigned Data packet with given @p name and empty Content.
+   *  @warning In certain contexts that use `Data::shared_from_this()`, Data must be created
+   *           using `make_shared`. Otherwise, `shared_from_this()` will trigger undefined behavior.
    */
   explicit
   Data(const Name& name = Name());
 
-  /** @brief Create from wire encoding
-   *  @warning In certain contexts that use Data::shared_from_this(), Data must be created
-   *           using `make_shared`. Otherwise, .shared_from_this() will trigger undefined behavior.
+  /** @brief Construct a Data packet by decoding from @p wire.
+   *  @param wire @c tlv::Data element as defined in NDN Packet Format v0.2 or v0.3.
+   *              It may be signed or unsigned.
+   *  @warning In certain contexts that use `Data::shared_from_this()`, Data must be created
+   *           using `make_shared`. Otherwise, `shared_from_this()` will trigger undefined behavior.
    */
   explicit
   Data(const Block& wire);
 
-  /** @brief Fast encoding or block size estimation
+  /** @brief Prepend wire encoding to @p encoder in NDN Packet Format v0.2.
    *  @param encoder EncodingEstimator or EncodingBuffer instance
    *  @param wantUnsignedPortionOnly If true, only prepends Name, MetaInfo, Content, and
    *         SignatureInfo to @p encoder, but omit SignatureValue and outmost Type-Length of Data
@@ -89,17 +91,22 @@
   const Block&
   wireEncode(EncodingBuffer& encoder, const Block& signatureValue) const;
 
-  /** @brief Encode to a wire format
+  /** @brief Encode to a @c Block.
+   *  @pre Data is signed.
+   *
+   *  Normally, this function encodes to NDN Packet Format v0.2. However, if this instance has
+   *  cached wire encoding (\c hasWire() is true), the cached encoding is returned and it might
+   *  be in v0.3 format.
    */
   const Block&
   wireEncode() const;
 
-  /** @brief Decode from the wire format
+  /** @brief Decode from @p wire in NDN Packet Format v0.2 or v0.3.
    */
   void
   wireDecode(const Block& wire);
 
-  /** @brief Check if already has wire
+  /** @brief Check if this instance has cached wire encoding.
    */
   bool
   hasWire() const
diff --git a/tests/unit-tests/data.t.cpp b/tests/unit-tests/data.t.cpp
index e2054a5..ccf4e5b 100644
--- a/tests/unit-tests/data.t.cpp
+++ b/tests/unit-tests/data.t.cpp
@@ -30,6 +30,7 @@
 #include "security/verification-helpers.hpp"
 #include "util/sha256.hpp"
 
+#include "block-literal.hpp"
 #include "boost-test.hpp"
 #include "identity-management-fixture.hpp"
 #include <boost/lexical_cast.hpp>
@@ -88,7 +89,7 @@
   BOOST_CHECK_EQUAL(d.getName(), "/");
   BOOST_CHECK_EQUAL(d.getContentType(), tlv::ContentType_Blob);
   BOOST_CHECK_EQUAL(d.getFreshnessPeriod(), DEFAULT_FRESHNESS_PERIOD);
-  BOOST_CHECK_EQUAL(d.getFinalBlockId(), name::Component());
+  BOOST_CHECK(!d.getFinalBlock());
   BOOST_CHECK_EQUAL(d.getContent().type(), tlv::Content);
   BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
   BOOST_CHECK(!d.getSignature());
@@ -205,7 +206,7 @@
                                 dataBlock.begin(), dataBlock.end());
 }
 
-BOOST_FIXTURE_TEST_CASE(Decode, DataSigningKeyFixture)
+BOOST_FIXTURE_TEST_CASE(Decode02, DataSigningKeyFixture)
 {
   Block dataBlock(DATA1, sizeof(DATA1));
   Data d(dataBlock);
@@ -225,6 +226,123 @@
   BOOST_CHECK(security::verifySignature(d, m_pubKey));
 }
 
+class Decode03Fixture
+{
+protected:
+  Decode03Fixture()
+  {
+    // initialize all elements to non-empty, to verify wireDecode clears them
+    d.setName("/A");
+    d.setContentType(tlv::ContentType_Key);
+    d.setContent("1504C0C1C2C3"_block);
+    d.setSignature(Signature("160A 1B0101 1C050703080142"_block,
+                   "1780 B48F1707A3BCA3CFC5F32DE51D9B46C32D7D262A21544EBDA88C3B415D637503"
+                        "FC9BEF20F88202A56AF9831E0D30205FD4154B08502BCDEE860267A5C3E03D8E"
+                        "A6CB74BE391C01E0A57B991B4404FC11B7D777F1B700A4B65F201118CF1840A8"
+                        "30A2A7C17DB4B7A8777E58515121AF9E2498627F8475414CDFD9801B8152AD5B"_block));
+  }
+
+protected:
+  Data d;
+};
+
+BOOST_FIXTURE_TEST_SUITE(Decode03, Decode03Fixture)
+
+BOOST_AUTO_TEST_CASE(MinimalNoSigValue)
+{
+  d.wireDecode("0607 0700 16031B0100"_block);
+  BOOST_CHECK_EQUAL(d.getName(), "/"); // empty Name is allowed in Data
+  BOOST_CHECK_EQUAL(d.getMetaInfo(), MetaInfo());
+  BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
+  BOOST_CHECK_EQUAL(d.getSignature().getType(), tlv::DigestSha256);
+  BOOST_CHECK_EQUAL(d.getSignature().getValue().value_size(), 0);
+}
+
+BOOST_AUTO_TEST_CASE(Minimal)
+{
+  d.wireDecode("062C 0703080144 16031B0100 "
+               "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block);
+  BOOST_CHECK_EQUAL(d.getName(), "/D");
+  BOOST_CHECK_EQUAL(d.getMetaInfo(), MetaInfo());
+  BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
+  BOOST_CHECK_EQUAL(d.getSignature().getType(), tlv::DigestSha256);
+  BOOST_CHECK_EQUAL(d.getSignature().getValue().value_size(), 32);
+
+  // encode without modification: retain original wire encoding
+  BOOST_CHECK_EQUAL(d.wireEncode().value_size(), 44);
+
+  // modify then re-encode as v0.2 format
+  d.setName("/E");
+  BOOST_CHECK(d.wireEncode() ==
+              "0630 0703080145 1400 1500 16031B0100 "
+              "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block);
+}
+
+BOOST_AUTO_TEST_CASE(Full)
+{
+  d.wireDecode("063C FC00 0703080144 FC00 1400 FC00 1500 FC00 16031B0100 FC00 "
+               "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76 FC00"_block);
+  BOOST_CHECK_EQUAL(d.getName(), "/D");
+  BOOST_CHECK_EQUAL(d.getMetaInfo(), MetaInfo());
+  BOOST_CHECK_EQUAL(d.getContent().value_size(), 0);
+  BOOST_CHECK_EQUAL(d.getSignature().getType(), tlv::DigestSha256);
+  BOOST_CHECK_EQUAL(d.getSignature().getValue().value_size(), 32);
+
+  // encode without modification: retain original wire encoding
+  BOOST_CHECK_EQUAL(d.wireEncode().value_size(), 60);
+
+  // modify then re-encode as v0.2 format
+  d.setName("/E");
+  BOOST_CHECK(d.wireEncode() ==
+              "0630 0703080145 1400 1500 16031B0100 "
+              "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block);
+}
+
+BOOST_AUTO_TEST_CASE(CriticalElementOutOfOrder)
+{
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0630 1400 0703080145 1500 16031B0100 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block),
+    tlv::Error);
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0630 0703080145 1500 1400 16031B0100 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block),
+    tlv::Error);
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0630 0703080145 1400 16031B0100 1500 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block),
+    tlv::Error);
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0630 0703080145 1400 1500 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76 16031B0100"_block),
+    tlv::Error);
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0652 0703080145 1400 1500 16031B0100 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block),
+    tlv::Error);
+}
+
+BOOST_AUTO_TEST_CASE(NameMissing)
+{
+  BOOST_CHECK_THROW(d.wireDecode("0605 16031B0100"_block), tlv::Error);
+}
+
+BOOST_AUTO_TEST_CASE(SigInfoMissing)
+{
+  BOOST_CHECK_THROW(d.wireDecode("0605 0703080144"_block), tlv::Error);
+}
+
+BOOST_AUTO_TEST_CASE(UnrecognizedCriticalElement)
+{
+  BOOST_CHECK_THROW(d.wireDecode(
+    "0632 0703080145 FB00 1400 1500 16031B0100 "
+    "1720612A79399E60304A9F701C1ECAC7956BF2F1B046E6C6F0D6C29B3FE3A29BAD76"_block),
+    tlv::Error);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // Decode03
+
 BOOST_FIXTURE_TEST_CASE(FullName, IdentityManagementFixture)
 {
   Data d(Name("/local/ndn/prefix"));