diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8fb03ba1ff..7b77c37393 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1077,6 +1077,8 @@ if(STATIC)
 endif()
 find_package(Boost 1.58 QUIET REQUIRED COMPONENTS system filesystem thread date_time chrono regex serialization program_options locale)
 add_definitions(-DBOOST_ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+add_definitions(-DBOOST_NO_AUTO_PTR)
+add_definitions(-DBOOST_UUID_DISABLE_ALIGNMENT) # This restores UUID's std::has_unique_object_representations property
 
 set(CMAKE_FIND_LIBRARY_SUFFIXES ${OLD_LIB_SUFFIXES})
 if(NOT Boost_FOUND)
diff --git a/contrib/epee/include/serialization/keyvalue_serialization.h b/contrib/epee/include/serialization/keyvalue_serialization.h
index 06d74329f1..fbbddc7d2f 100644
--- a/contrib/epee/include/serialization/keyvalue_serialization.h
+++ b/contrib/epee/include/serialization/keyvalue_serialization.h
@@ -98,16 +98,18 @@ public: \
 #define KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(varialble, val_name) \
   epee::serialization::selector<is_store>::serialize_t_val_as_blob(this_ref.varialble, stg, hparent_section, val_name); 
 
-#define KV_SERIALIZE_VAL_POD_AS_BLOB_N(varialble, val_name) \
-  static_assert(std::is_pod<decltype(this_ref.varialble)>::value, "t_type must be a POD type."); \
-  KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(varialble, val_name)
+#define KV_SERIALIZE_VAL_POD_AS_BLOB_N(variable, val_name) \
+  static_assert(std::is_trivially_copyable<decltype(this_ref.variable)>(), "t_type must be a trivially copyable type."); \
+  static_assert(std::is_standard_layout<decltype(this_ref.variable)>(), "t_type must be a standard layout type."); \
+  KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(variable, val_name)
 
-#define KV_SERIALIZE_VAL_POD_AS_BLOB_OPT_N(varialble, val_name, default_value) \
+#define KV_SERIALIZE_VAL_POD_AS_BLOB_OPT_N(variable, val_name, default_value) \
   do { \
-    static_assert(std::is_pod<decltype(this_ref.varialble)>::value, "t_type must be a POD type."); \
-    bool ret = KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(varialble, val_name); \
+    static_assert(std::is_trivially_copyable<decltype(this_ref.variable)>(), "t_type must be a trivially copyable type."); \
+    static_assert(std::is_standard_layout<decltype(this_ref.variable)>(), "t_type must be a standard layout type."); \
+    bool ret = KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(variable, val_name) \
     if (!ret) \
-      epee::serialize_default(this_ref.varialble, default_value); \
+      epee::serialize_default(this_ref.variable, default_value); \
   } while(0);
 
 #define KV_SERIALIZE_CONTAINER_POD_AS_BLOB_N(varialble, val_name) \
@@ -118,7 +120,7 @@ public: \
 #define KV_SERIALIZE(varialble)                           KV_SERIALIZE_N(varialble, #varialble)
 #define KV_SERIALIZE_VAL_POD_AS_BLOB(varialble)           KV_SERIALIZE_VAL_POD_AS_BLOB_N(varialble, #varialble)
 #define KV_SERIALIZE_VAL_POD_AS_BLOB_OPT(varialble, def)  KV_SERIALIZE_VAL_POD_AS_BLOB_OPT_N(varialble, #varialble, def)
-#define KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(varialble)     KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(varialble, #varialble) //skip is_pod compile time check
+#define KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE(varialble)     KV_SERIALIZE_VAL_POD_AS_BLOB_FORCE_N(varialble, #varialble) //skip is_trivially_copyable and is_standard_layout compile time check
 #define KV_SERIALIZE_CONTAINER_POD_AS_BLOB(varialble)     KV_SERIALIZE_CONTAINER_POD_AS_BLOB_N(varialble, #varialble)
 #define KV_SERIALIZE_OPT(variable,default_value)          KV_SERIALIZE_OPT_N(variable, #variable, default_value)
 
diff --git a/contrib/epee/include/span.h b/contrib/epee/include/span.h
index 23bd51f8c2..01dc387d6d 100644
--- a/contrib/epee/include/span.h
+++ b/contrib/epee/include/span.h
@@ -133,17 +133,14 @@ namespace epee
     return {src.data(), src.size()};
   }
 
-  template<typename T>
-  constexpr bool has_padding() noexcept
-  {
-    return !std::is_standard_layout<T>() || alignof(T) != 1;
-  }
-
   //! \return Cast data from `src` as `span<const std::uint8_t>`.
   template<typename T>
   span<const std::uint8_t> to_byte_span(const span<const T> src) noexcept
   {
-    static_assert(!has_padding<T>(), "source type may have padding");
+    static_assert(!std::is_empty<T>(), "empty value types will not work -> sizeof == 1");
+    static_assert(std::is_standard_layout<T>(), "type must have standard layout");
+    static_assert(std::is_trivially_copyable<T>(), "type must be trivially copyable");
+    static_assert(alignof(T) == 1, "type may have padding");
     return {reinterpret_cast<const std::uint8_t*>(src.data()), src.size_bytes()}; 
   }
 
@@ -153,7 +150,9 @@ namespace epee
   {
     using value_type = typename T::value_type;
     static_assert(!std::is_empty<value_type>(), "empty value types will not work -> sizeof == 1");
-    static_assert(!has_padding<value_type>(), "source value type may have padding");
+    static_assert(std::is_standard_layout<value_type>(), "value type must have standard layout");
+    static_assert(std::is_trivially_copyable<value_type>(), "value type must be trivially copyable");
+    static_assert(alignof(value_type) == 1, "value type may have padding");
     return {reinterpret_cast<std::uint8_t*>(src.data()), src.size() * sizeof(value_type)};
   }
 
@@ -162,7 +161,9 @@ namespace epee
   span<const std::uint8_t> as_byte_span(const T& src) noexcept
   {
     static_assert(!std::is_empty<T>(), "empty types will not work -> sizeof == 1");
-    static_assert(!has_padding<T>(), "source type may have padding");
+    static_assert(std::is_standard_layout<T>(), "type must have standard layout");
+    static_assert(std::is_trivially_copyable<T>(), "type must be trivially copyable");
+    static_assert(alignof(T) == 1, "type may have padding");
     return {reinterpret_cast<const std::uint8_t*>(std::addressof(src)), sizeof(T)};
   }
 
@@ -171,7 +172,9 @@ namespace epee
   span<std::uint8_t> as_mut_byte_span(T& src) noexcept
   {
     static_assert(!std::is_empty<T>(), "empty types will not work -> sizeof == 1");
-    static_assert(!has_padding<T>(), "source type may have padding");
+    static_assert(std::is_standard_layout<T>(), "type must have standard layout");
+    static_assert(std::is_trivially_copyable<T>(), "type must be trivially copyable");
+    static_assert(alignof(T) == 1, "type may have padding");
     return {reinterpret_cast<std::uint8_t*>(std::addressof(src)), sizeof(T)};
   }
 
diff --git a/contrib/epee/include/string_tools.h b/contrib/epee/include/string_tools.h
index 31c55b97ba..7de73cbf5a 100644
--- a/contrib/epee/include/string_tools.h
+++ b/contrib/epee/include/string_tools.h
@@ -91,6 +91,7 @@ namespace string_tools
   std::string pod_to_hex(const t_pod_type& s)
   {
     static_assert(std::is_standard_layout<t_pod_type>(), "expected standard layout type");
+    static_assert(alignof(t_pod_type) == 1, "type may have padding");
     return to_hex::string(as_byte_span(s));
   }
   //----------------------------------------------------------------------------
@@ -98,6 +99,8 @@ namespace string_tools
   bool hex_to_pod(const boost::string_ref hex_str, t_pod_type& s)
   {
     static_assert(std::is_standard_layout<t_pod_type>(), "expected standard layout type");
+    static_assert(alignof(t_pod_type) == 1, "type may have padding");
+    static_assert(std::is_trivially_copyable<t_pod_type>(), "type must be trivially copyable");
     return from_hex::to_buffer(as_mut_byte_span(s), hex_str);
   }
   //----------------------------------------------------------------------------
diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h
index d8cd6c6a01..ee1cac04a6 100644
--- a/src/crypto/crypto.h
+++ b/src/crypto/crypto.h
@@ -171,7 +171,9 @@ namespace crypto {
   /* Generate a value filled with random bytes.
    */
   template<typename T>
-  typename std::enable_if<std::is_pod<T>::value, T>::type rand() {
+  T rand() {
+    static_assert(std::is_standard_layout<T>(), "cannot write random bytes into non-standard layout type");
+    static_assert(std::is_trivially_copyable<T>(), "cannot write random bytes into non-trivially copyable type");
     typename std::remove_cv<T>::type res;
     generate_random_bytes_thread_safe(sizeof(T), (uint8_t*)&res);
     return res;
@@ -314,8 +316,14 @@ namespace crypto {
   inline std::ostream &operator <<(std::ostream &o, const crypto::public_key &v) {
     epee::to_hex::formatted(o, epee::as_byte_span(v)); return o;
   }
-  inline std::ostream &operator <<(std::ostream &o, const crypto::secret_key &v) {
-    epee::to_hex::formatted(o, epee::as_byte_span(v)); return o;
+  /* Do NOT overload the << operator for crypto::secret_key here. Use secret_key_explicit_print_ref
+   * instead to prevent accidental implicit dumping of secret key material to the logs (which has
+   * happened before). For the same reason, do not overload it for crypto::ec_scalar either since
+   * crypto::secret_key is a subclass. I'm not sorry that it's obtuse; that's the point, bozo.
+   */
+  struct secret_key_explicit_print_ref { const crypto::secret_key &sk; };
+  inline std::ostream &operator <<(std::ostream &o, const secret_key_explicit_print_ref v) {
+    epee::to_hex::formatted(o, epee::as_byte_span(unwrap(unwrap(v.sk)))); return o;
   }
   inline std::ostream &operator <<(std::ostream &o, const crypto::key_derivation &v) {
     epee::to_hex::formatted(o, epee::as_byte_span(v)); return o;
diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index 8be23583b5..e6e424c719 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -292,7 +292,7 @@ namespace cryptonote
     bool r = hwdev.generate_key_derivation(tx_public_key, ack.m_view_secret_key, recv_derivation);
     if (!r)
     {
-      MWARNING("key image helper: failed to generate_key_derivation(" << tx_public_key << ", " << ack.m_view_secret_key << ")");
+      MWARNING("key image helper: failed to generate_key_derivation(" << tx_public_key << ", <viewkey>)");
       memcpy(&recv_derivation, rct::identity().bytes, sizeof(recv_derivation));
     }
 
@@ -303,7 +303,7 @@ namespace cryptonote
       r = hwdev.generate_key_derivation(additional_tx_public_keys[i], ack.m_view_secret_key, additional_recv_derivation);
       if (!r)
       {
-        MWARNING("key image helper: failed to generate_key_derivation(" << additional_tx_public_keys[i] << ", " << ack.m_view_secret_key << ")");
+        MWARNING("key image helper: failed to generate_key_derivation(" << additional_tx_public_keys[i] << ", <viewkey>)");
       }
       else
       {
diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp
index dc9d6612f6..8f044154b1 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.cpp
+++ b/src/cryptonote_core/cryptonote_tx_utils.cpp
@@ -144,7 +144,7 @@ namespace cryptonote
       crypto::key_derivation derivation = AUTO_VAL_INIT(derivation);
       crypto::public_key out_eph_public_key = AUTO_VAL_INIT(out_eph_public_key);
       bool r = crypto::generate_key_derivation(miner_address.m_view_public_key, txkey.sec, derivation);
-      CHECK_AND_ASSERT_MES(r, false, "while creating outs: failed to generate_key_derivation(" << miner_address.m_view_public_key << ", " << txkey.sec << ")");
+      CHECK_AND_ASSERT_MES(r, false, "while creating outs: failed to generate_key_derivation(" << miner_address.m_view_public_key << ", " << crypto::secret_key_explicit_print_ref{txkey.sec} << ")");
 
       r = crypto::derive_public_key(derivation, no, miner_address.m_spend_public_key, out_eph_public_key);
       CHECK_AND_ASSERT_MES(r, false, "while creating outs: failed to derive_public_key(" << derivation << ", " << no << ", "<< miner_address.m_spend_public_key << ")");
@@ -484,7 +484,7 @@ namespace cryptonote
           crypto::generate_ring_signature(tx_prefix_hash, boost::get<txin_to_key>(tx.vin[i]).k_image, keys_ptrs, in_contexts[i].in_ephemeral.sec, src_entr.real_output, sigs.data());
         ss_ring_s << "signatures:" << ENDL;
         std::for_each(sigs.begin(), sigs.end(), [&](const crypto::signature& s){ss_ring_s << s << ENDL;});
-        ss_ring_s << "prefix_hash:" << tx_prefix_hash << ENDL << "in_ephemeral_key: " << in_contexts[i].in_ephemeral.sec << ENDL << "real_output: " << src_entr.real_output << ENDL;
+        ss_ring_s << "prefix_hash:" << tx_prefix_hash << ENDL << "in_ephemeral_key: " << crypto::secret_key_explicit_print_ref{in_contexts[i].in_ephemeral.sec} << ENDL << "real_output: " << src_entr.real_output << ENDL;
         i++;
       }
 
diff --git a/src/cryptonote_protocol/block_queue.cpp b/src/cryptonote_protocol/block_queue.cpp
index 4e65eafa4f..e5a4c0c99a 100644
--- a/src/cryptonote_protocol/block_queue.cpp
+++ b/src/cryptonote_protocol/block_queue.cpp
@@ -40,15 +40,6 @@
 #undef MONERO_DEFAULT_LOG_CATEGORY
 #define MONERO_DEFAULT_LOG_CATEGORY "cn.block_queue"
 
-namespace std {
-  static_assert(sizeof(size_t) <= sizeof(boost::uuids::uuid), "boost::uuids::uuid too small");
-  template<> struct hash<boost::uuids::uuid> {
-    std::size_t operator()(const boost::uuids::uuid &_v) const {
-      return reinterpret_cast<const std::size_t &>(_v);
-    }
-  };
-}
-
 namespace cryptonote
 {
 
@@ -472,7 +463,7 @@ bool block_queue::has_spans(const boost::uuids::uuid &connection_id) const
 float block_queue::get_speed(const boost::uuids::uuid &connection_id) const
 {
   boost::unique_lock<boost::recursive_mutex> lock(mutex);
-  std::unordered_map<boost::uuids::uuid, float> speeds;
+  std::unordered_map<boost::uuids::uuid, float, boost::hash<boost::uuids::uuid>> speeds;
   for (const auto &span: blocks)
   {
     if (span.blocks.empty())
@@ -480,7 +471,7 @@ float block_queue::get_speed(const boost::uuids::uuid &connection_id) const
     // note that the average below does not average over the whole set, but over the
     // previous pseudo average and the latest rate: this gives much more importance
     // to the latest measurements, which is fine here
-    std::unordered_map<boost::uuids::uuid, float>::iterator i = speeds.find(span.connection_id);
+    const auto i = speeds.find(span.connection_id);
     if (i == speeds.end())
       speeds.insert(std::make_pair(span.connection_id, span.rate));
     else
diff --git a/src/device/device_default.cpp b/src/device/device_default.cpp
index d70ece229c..c770a6e221 100644
--- a/src/device/device_default.cpp
+++ b/src/device/device_default.cpp
@@ -317,13 +317,15 @@ namespace hw {
             {
             // sending change to yourself; derivation = a*R
                 r = generate_key_derivation(txkey_pub, sender_account_keys.m_view_secret_key, derivation);
-                CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to generate_key_derivation(" << txkey_pub << ", " << sender_account_keys.m_view_secret_key << ")");
+                CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to generate_key_derivation(" << txkey_pub << ", <viewkey>)");
             }
             else
             {
             // sending to the recipient; derivation = r*A (or s*C in the subaddress scheme)
-                r = generate_key_derivation(dst_entr.addr.m_view_public_key, dst_entr.is_subaddress && need_additional_txkeys ? additional_txkey.sec : tx_key, derivation);
-                CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to generate_key_derivation(" << dst_entr.addr.m_view_public_key << ", " << (dst_entr.is_subaddress && need_additional_txkeys ? additional_txkey.sec : tx_key) << ")");
+                const crypto::secret_key &tx_privkey{dst_entr.is_subaddress && need_additional_txkeys ? additional_txkey.sec : tx_key};
+                r = generate_key_derivation(dst_entr.addr.m_view_public_key, tx_privkey, derivation);
+                CHECK_AND_ASSERT_MES(r, false, "at creation outs: failed to generate_key_derivation("
+                    << dst_entr.addr.m_view_public_key << ", " << crypto::secret_key_explicit_print_ref{tx_privkey} << ")");
             }
 
             if (need_additional_txkeys)
diff --git a/src/lmdb/util.h b/src/lmdb/util.h
index c6c75bc004..392ff20390 100644
--- a/src/lmdb/util.h
+++ b/src/lmdb/util.h
@@ -127,7 +127,7 @@ namespace lmdb
     /*!
         A LMDB comparison function that uses `std::memcmp`.
 
-        \toaram T is `!epee::has_padding`
+        \toaram T has standard layout and an alignment of 1
         \tparam offset to `T` within the value.
 
         \return The result of `std::memcmp` over the value.
@@ -135,7 +135,7 @@ namespace lmdb
     template<typename T, std::size_t offset = 0>
     inline int compare(MDB_val const* left, MDB_val const* right) noexcept
     {
-        static_assert(!epee::has_padding<T>(), "memcmp will not work");
+        static_assert(std::is_standard_layout<T>() && alignof(T) == 1, "memcmp will not work");
         if (!left || !right || left->mv_size < sizeof(T) + offset || right->mv_size < sizeof(T) + offset)
         {
             assert("invalid use of custom comparison" == 0);
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index b9e30f9d94..011b1c7613 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -1979,7 +1979,7 @@ bool simple_wallet::rpc_payment_info(const std::vector<std::string> &args)
     crypto::public_key pkey;
     crypto::secret_key_to_public_key(m_wallet->get_rpc_client_secret_key(), pkey);
     message_writer() << tr("RPC client ID: ") << pkey;
-    message_writer() << tr("RPC client secret key: ") << m_wallet->get_rpc_client_secret_key();
+    message_writer() << tr("RPC client secret key: ") << crypto::secret_key_explicit_print_ref{m_wallet->get_rpc_client_secret_key()};
     if (!m_wallet->get_rpc_payment_info(false, payment_required, credits, diff, credits_per_hash_found, hashing_blob, height, seed_height, seed_hash, next_seed_hash, cookie))
     {
       fail_msg_writer() << tr("Failed to query daemon");
@@ -8026,9 +8026,9 @@ bool simple_wallet::submit_transfer(const std::vector<std::string> &args_)
 std::string get_tx_key_stream(crypto::secret_key tx_key, std::vector<crypto::secret_key> additional_tx_keys)
 {
   ostringstream oss;
-  oss << epee::string_tools::pod_to_hex(tx_key);
+  oss << epee::string_tools::pod_to_hex(unwrap(unwrap(tx_key)));
   for (size_t i = 0; i < additional_tx_keys.size(); ++i)
-    oss << epee::string_tools::pod_to_hex(additional_tx_keys[i]);
+    oss << epee::string_tools::pod_to_hex(unwrap(unwrap(additional_tx_keys[i])));
   return oss.str();
 }
 
diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp
index fc4f891281..2ed14bfbd5 100644
--- a/src/wallet/api/wallet.cpp
+++ b/src/wallet/api/wallet.cpp
@@ -881,7 +881,7 @@ std::string WalletImpl::integratedAddress(const std::string &payment_id) const
 
 std::string WalletImpl::secretViewKey() const
 {
-    return epee::string_tools::pod_to_hex(m_wallet->get_account().get_keys().m_view_secret_key);
+    return epee::string_tools::pod_to_hex(unwrap(unwrap(m_wallet->get_account().get_keys().m_view_secret_key)));
 }
 
 std::string WalletImpl::publicViewKey() const
@@ -891,7 +891,7 @@ std::string WalletImpl::publicViewKey() const
 
 std::string WalletImpl::secretSpendKey() const
 {
-    return epee::string_tools::pod_to_hex(m_wallet->get_account().get_keys().m_spend_secret_key);
+    return epee::string_tools::pod_to_hex(unwrap(unwrap(m_wallet->get_account().get_keys().m_spend_secret_key)));
 }
 
 std::string WalletImpl::publicSpendKey() const
@@ -1878,9 +1878,9 @@ std::string WalletImpl::getTxKey(const std::string &txid_str) const
         {
             clearStatus();
             std::ostringstream oss;
-            oss << epee::string_tools::pod_to_hex(tx_key);
+            oss << epee::string_tools::pod_to_hex(unwrap(unwrap(tx_key)));
             for (size_t i = 0; i < additional_tx_keys.size(); ++i)
-                oss << epee::string_tools::pod_to_hex(additional_tx_keys[i]);
+                oss << epee::string_tools::pod_to_hex(unwrap(unwrap(additional_tx_keys[i])));
             return oss.str();
         }
         else
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index ad8c361909..90b5731695 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -4613,7 +4613,7 @@ boost::optional<wallet2::keys_file_data> wallet2::get_keys_file_data(const epee:
     original_address = get_account_address_as_str(m_nettype, false, m_original_address);
     value.SetString(original_address.c_str(), original_address.length());
     json.AddMember("original_address", value, json.GetAllocator());
-    original_view_secret_key = epee::string_tools::pod_to_hex(m_original_view_secret_key);
+    original_view_secret_key = epee::string_tools::pod_to_hex(unwrap(unwrap(m_original_view_secret_key)));
     value.SetString(original_view_secret_key.c_str(), original_view_secret_key.length());
     json.AddMember("original_view_secret_key", value, json.GetAllocator());
   }
@@ -7077,7 +7077,7 @@ void wallet2::commit_tx(pending_tx& ptx)
     cryptonote::COMMAND_RPC_SUBMIT_RAW_TX::request oreq;
     cryptonote::COMMAND_RPC_SUBMIT_RAW_TX::response ores;
     oreq.address = get_account().get_public_address_str(m_nettype);
-    oreq.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+    oreq.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
     oreq.tx = epee::string_tools::buff_to_hex_nodelimer(tx_to_blob(ptx.tx));
     {
       const boost::lock_guard<boost::recursive_mutex> lock{m_daemon_rpc_mutex};
@@ -10075,7 +10075,7 @@ bool wallet2::light_wallet_login(bool &new_address)
   tools::COMMAND_RPC_LOGIN::request request;
   tools::COMMAND_RPC_LOGIN::response response;
   request.address = get_account().get_public_address_str(m_nettype);
-  request.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+  request.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
   // Always create account if it doesn't exist.
   request.create_account = true;
   m_daemon_rpc_mutex.lock();
@@ -10102,7 +10102,7 @@ bool wallet2::light_wallet_import_wallet_request(tools::COMMAND_RPC_IMPORT_WALLE
   MDEBUG("Light wallet import wallet request");
   tools::COMMAND_RPC_IMPORT_WALLET_REQUEST::request oreq;
   oreq.address = get_account().get_public_address_str(m_nettype);
-  oreq.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+  oreq.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
   m_daemon_rpc_mutex.lock();
   bool r = invoke_http_json("/import_wallet_request", oreq, response, rpc_timeout, "POST");
   m_daemon_rpc_mutex.unlock();
@@ -10121,7 +10121,7 @@ void wallet2::light_wallet_get_unspent_outs()
   
   oreq.amount = "0";
   oreq.address = get_account().get_public_address_str(m_nettype);
-  oreq.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+  oreq.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
   // openMonero specific
   oreq.dust_threshold = boost::lexical_cast<std::string>(::config::DEFAULT_DUST_THRESHOLD);
   // below are required by openMonero api - but are not used.
@@ -10273,7 +10273,7 @@ bool wallet2::light_wallet_get_address_info(tools::COMMAND_RPC_GET_ADDRESS_INFO:
   tools::COMMAND_RPC_GET_ADDRESS_INFO::request request;
   
   request.address = get_account().get_public_address_str(m_nettype);
-  request.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+  request.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
   m_daemon_rpc_mutex.lock();
   bool r = invoke_http_json("/get_address_info", request, response, rpc_timeout, "POST");
   m_daemon_rpc_mutex.unlock();
@@ -10290,7 +10290,7 @@ void wallet2::light_wallet_get_address_txs()
   tools::COMMAND_RPC_GET_ADDRESS_TXS::response ires;
   
   ireq.address = get_account().get_public_address_str(m_nettype);
-  ireq.view_key = string_tools::pod_to_hex(get_account().get_keys().m_view_secret_key);
+  ireq.view_key = string_tools::pod_to_hex(unwrap(unwrap(get_account().get_keys().m_view_secret_key)));
   m_daemon_rpc_mutex.lock();
   bool r = invoke_http_json("/get_address_txs", ireq, ires, rpc_timeout, "POST");
   m_daemon_rpc_mutex.unlock();
@@ -10520,7 +10520,7 @@ bool wallet2::light_wallet_key_image_is_ours(const crypto::key_image& key_image,
   const account_keys& ack = get_account().get_keys();
   crypto::key_derivation derivation;
   bool r = crypto::generate_key_derivation(tx_public_key, ack.m_view_secret_key, derivation);
-  CHECK_AND_ASSERT_MES(r, false, "failed to generate_key_derivation(" << tx_public_key << ", " << ack.m_view_secret_key << ")");
+  CHECK_AND_ASSERT_MES(r, false, "failed to generate_key_derivation(" << tx_public_key << ", " << crypto::secret_key_explicit_print_ref{ack.m_view_secret_key} << ")");
 
   r = crypto::derive_public_key(derivation, out_index, ack.m_account_address.m_spend_public_key, in_ephemeral.pub);
   CHECK_AND_ASSERT_MES(r, false, "failed to derive_public_key (" << derivation << ", " << out_index << ", " << ack.m_account_address.m_spend_public_key << ")");
@@ -10528,7 +10528,7 @@ bool wallet2::light_wallet_key_image_is_ours(const crypto::key_image& key_image,
   crypto::derive_secret_key(derivation, out_index, ack.m_spend_secret_key, in_ephemeral.sec);
   crypto::public_key out_pkey_test;
   r = crypto::secret_key_to_public_key(in_ephemeral.sec, out_pkey_test);
-  CHECK_AND_ASSERT_MES(r, false, "failed to secret_key_to_public_key(" << in_ephemeral.sec << ")");
+  CHECK_AND_ASSERT_MES(r, false, "failed to secret_key_to_public_key(" << crypto::secret_key_explicit_print_ref{in_ephemeral.sec} << ")");
   CHECK_AND_ASSERT_MES(in_ephemeral.pub == out_pkey_test, false, "derived secret key doesn't match derived public key");
 
   crypto::generate_key_image(in_ephemeral.pub, in_ephemeral.sec, calculated_key_image);
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index b1419949f8..3c548de135 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -1247,9 +1247,9 @@ namespace tools
       res.tx_hash_list.push_back(epee::string_tools::pod_to_hex(cryptonote::get_transaction_hash(ptx.tx)));
       if (req.get_tx_keys)
       {
-        res.tx_key_list.push_back(epee::string_tools::pod_to_hex(ptx.tx_key));
+        res.tx_key_list.push_back(epee::string_tools::pod_to_hex(unwrap(unwrap(ptx.tx_key))));
         for (const crypto::secret_key& additional_tx_key : ptx.additional_tx_keys)
-          res.tx_key_list.back() += epee::string_tools::pod_to_hex(additional_tx_key);
+          res.tx_key_list.back() += epee::string_tools::pod_to_hex(unwrap(unwrap(additional_tx_key)));
       }
     }
 
diff --git a/tests/benchmark.cpp b/tests/benchmark.cpp
index 6a845d61a4..660783dd91 100644
--- a/tests/benchmark.cpp
+++ b/tests/benchmark.cpp
@@ -109,7 +109,7 @@ namespace
     template<typename T>
     bool compare(const T& lhs, const T& rhs) noexcept
     {
-        static_assert(!epee::has_padding<T>(), "type might have padding");
+        static_assert(std::is_standard_layout<T>() && alignof(T) == 1, "type might have padding");
         return std::memcmp(std::addressof(lhs), std::addressof(rhs), sizeof(T)) == 0;
     }
 
diff --git a/tests/core_tests/multisig.cpp b/tests/core_tests/multisig.cpp
index 966c761163..1d3a6a3a10 100644
--- a/tests/core_tests/multisig.cpp
+++ b/tests/core_tests/multisig.cpp
@@ -227,13 +227,13 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
         CHECK_AND_ASSERT_MES(r, false, "Failed to generate multisig export key image");
       }
       MDEBUG("Party " << msidx << ":");
-      MDEBUG("spend: sec " << miner_account[msidx].get_keys().m_spend_secret_key << ", pub " << miner_account[msidx].get_keys().m_account_address.m_spend_public_key);
-      MDEBUG("view: sec " << miner_account[msidx].get_keys().m_view_secret_key << ", pub " << miner_account[msidx].get_keys().m_account_address.m_view_public_key);
+      MDEBUG("spend: sec " << crypto::secret_key_explicit_print_ref{miner_account[msidx].get_keys().m_spend_secret_key} << ", pub " << miner_account[msidx].get_keys().m_account_address.m_spend_public_key);
+      MDEBUG("view: sec " << crypto::secret_key_explicit_print_ref{miner_account[msidx].get_keys().m_view_secret_key} << ", pub " << miner_account[msidx].get_keys().m_account_address.m_view_public_key);
       for (const auto &k: miner_account[msidx].get_multisig_keys())
-        MDEBUG("msk: " << k);
+        MDEBUG("msk: " << crypto::secret_key_explicit_print_ref{k});
       for (size_t n = 0; n < account_k[msidx][tdidx].size(); ++n)
       {
-        MDEBUG("k: " << account_k[msidx][tdidx][n]);
+        MDEBUG("k: " << crypto::secret_key_explicit_print_ref{account_k[msidx][tdidx][n]});
         MDEBUG("L: " << account_L[msidx][tdidx][n]);
         MDEBUG("R: " << account_R[msidx][tdidx][n]);
       }
@@ -406,7 +406,7 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
       MDEBUG("signing with k " << k.back()[n]);
     MDEBUG("signing with sk " << skey);
     for (const auto &sk: used_keys)
-      MDEBUG("  created with sk " << sk);
+      MDEBUG("  created with sk " << crypto::secret_key_explicit_print_ref{sk});
     CHECK_AND_ASSERT_MES(signer_tx_builder.next_partial_sign(sig.total_alpha_G, sig.total_alpha_H, k, skey, sig.c_0, sig.s), false, "error: multisig::signing::tx_builder_ringct_t::next_partial_sign");
 
     // in round-robin signing, the last signer finalizes the tx
diff --git a/tests/functional_tests/make_test_signature.cc b/tests/functional_tests/make_test_signature.cc
index e9dab8bd46..09a3f51c1a 100644
--- a/tests/functional_tests/make_test_signature.cc
+++ b/tests/functional_tests/make_test_signature.cc
@@ -48,7 +48,7 @@ int main(int argc, const char **argv)
     crypto::public_key pkey;
     crypto::random32_unbiased((unsigned char*)skey.data);
     crypto::secret_key_to_public_key(skey, pkey);
-    printf("%s %s\n", epee::string_tools::pod_to_hex(skey).c_str(), epee::string_tools::pod_to_hex(pkey).c_str());
+    printf("%s %s\n", epee::string_tools::pod_to_hex(unwrap(unwrap(skey))).c_str(), epee::string_tools::pod_to_hex(pkey).c_str());
     return 0;
   }
 
diff --git a/tests/unit_tests/crypto.cpp b/tests/unit_tests/crypto.cpp
index 7f926534a3..329992463c 100644
--- a/tests/unit_tests/crypto.cpp
+++ b/tests/unit_tests/crypto.cpp
@@ -72,10 +72,10 @@ TEST(Crypto, Ostream)
   EXPECT_TRUE(is_formatted<crypto::hash8>());
   EXPECT_TRUE(is_formatted<crypto::hash>());
   EXPECT_TRUE(is_formatted<crypto::public_key>());
-  EXPECT_TRUE(is_formatted<crypto::secret_key>());
   EXPECT_TRUE(is_formatted<crypto::signature>());
   EXPECT_TRUE(is_formatted<crypto::key_derivation>());
   EXPECT_TRUE(is_formatted<crypto::key_image>());
+  EXPECT_TRUE(is_formatted<rct::key>());
 }
 
 TEST(Crypto, null_keys)
diff --git a/tests/unit_tests/multisig.cpp b/tests/unit_tests/multisig.cpp
index 3b3c4197c0..71416aaf33 100644
--- a/tests/unit_tests/multisig.cpp
+++ b/tests/unit_tests/multisig.cpp
@@ -80,7 +80,7 @@ static void make_wallet(unsigned int idx, tools::wallet2 &wallet)
     wallet.generate("", "", spendkey, true, false);
     ASSERT_TRUE(test_addresses[idx].address == wallet.get_account().get_public_address_str(cryptonote::TESTNET));
     wallet.decrypt_keys("");
-    ASSERT_TRUE(test_addresses[idx].spendkey == epee::string_tools::pod_to_hex(wallet.get_account().get_keys().m_spend_secret_key));
+    ASSERT_TRUE(test_addresses[idx].spendkey == epee::string_tools::pod_to_hex(unwrap(unwrap(wallet.get_account().get_keys().m_spend_secret_key))));
     wallet.encrypt_keys("");
   }
   catch (const std::exception &e)
diff --git a/tests/unit_tests/serialization.cpp b/tests/unit_tests/serialization.cpp
index 0fdd832856..fdf6032722 100644
--- a/tests/unit_tests/serialization.cpp
+++ b/tests/unit_tests/serialization.cpp
@@ -1103,7 +1103,7 @@ TEST(Serialization, portability_signed_tx)
   ASSERT_TRUE(ptx.selected_transfers.front() == 2);
   // ptx.{key_images, tx_key}
   ASSERT_TRUE(ptx.key_images == "<6c3cd6af97c4070a7aef9b1344e7463e29c7cd245076fdb65da447a34da3ca76> ");
-  ASSERT_TRUE(epee::string_tools::pod_to_hex(ptx.tx_key) == "0100000000000000000000000000000000000000000000000000000000000000");
+  ASSERT_TRUE(epee::string_tools::pod_to_hex(unwrap(unwrap(ptx.tx_key))) == "0100000000000000000000000000000000000000000000000000000000000000");
   // ptx.dests
   ASSERT_TRUE(ptx.dests.size() == 1);
   ASSERT_TRUE(ptx.dests[0].amount == 1400000000000);