diff --git a/src/detail/pending-interest.hpp b/src/detail/pending-interest.hpp
index c481acc..c0a35e3 100644
--- a/src/detail/pending-interest.hpp
+++ b/src/detail/pending-interest.hpp
@@ -14,7 +14,8 @@
 
 namespace ndn {
 
-class PendingInterest {
+class PendingInterest
+{
 public:
   typedef function<void(const Interest&, Data&)> OnData;
   typedef function<void(const Interest&)> OnTimeout;
diff --git a/src/encoding/block.hpp b/src/encoding/block.hpp
index 8079531..6777f77 100644
--- a/src/encoding/block.hpp
+++ b/src/encoding/block.hpp
@@ -30,7 +30,7 @@
   typedef element_container::iterator        element_iterator;
   typedef element_container::const_iterator  element_const_iterator;
 
-  /// @brief Error that can be thrown from the block
+  /// @brief Error that can be thrown from Block
   class Error : public Tlv::Error
   {
   public:
@@ -53,7 +53,8 @@
   Block(const EncodingBuffer& buffer);
 
   /**
-   * @brief A helper version of a constructor to create Block from the raw buffer (type and value-length parsing)
+   * @brief A helper version of a constructor to create Block from the raw buffer (type
+   * and value-length parsing)
    *
    * This constructor provides ability of implicit conversion from ConstBufferPtr to Block
    */
@@ -70,7 +71,8 @@
         bool verifyLength = true);
 
   /**
-   * @brief A helper version of a constructor to create Block from the raw buffer (type and value-length parsing)
+   * @brief A helper version of a constructor to create Block from the raw buffer (type
+   * and value-length parsing)
    */
   Block(const uint8_t* buffer, size_t maxlength);
 
diff --git a/src/encoding/cryptopp/asn_ext.hpp b/src/encoding/cryptopp/asn_ext.hpp
index 5d726dc..afd33dc 100644
--- a/src/encoding/cryptopp/asn_ext.hpp
+++ b/src/encoding/cryptopp/asn_ext.hpp
@@ -9,26 +9,11 @@
 #ifndef NDN_ASN_EXT_HPP
 #define NDN_ASN_EXT_HPP
 
-#include <stdexcept>
 #include "../../common.hpp"
 #include "../../security/cryptopp.hpp"
 
 namespace ndn {
 
-namespace asn {
-
-class Error : public std::runtime_error
-{
-public:
-  explicit
-  Error(const std::string& what)
-    : std::runtime_error(what)
-  {
-  }
-};
-
-} // namespace asn
-
 size_t
 DEREncodeGeneralTime(CryptoPP::BufferedTransformation& bt,
                      const time::system_clock::TimePoint& time);
diff --git a/src/encoding/oid.hpp b/src/encoding/oid.hpp
index e7b1beb..0cd570d 100644
--- a/src/encoding/oid.hpp
+++ b/src/encoding/oid.hpp
@@ -11,11 +11,14 @@
 
 #include "../common.hpp"
 
-namespace CryptoPP { class BufferedTransformation; }
+namespace CryptoPP {
+class BufferedTransformation;
+}
 
 namespace ndn {
 
-class OID {
+class OID
+{
 public:
   OID ()
   {
diff --git a/src/exclude.hpp b/src/exclude.hpp
index 9fb5c3a..d086f14 100644
--- a/src/exclude.hpp
+++ b/src/exclude.hpp
@@ -21,12 +21,12 @@
 class Exclude
 {
 public:
-  class Error : public std::runtime_error
+  class Error : public Tlv::Error
   {
   public:
     explicit
     Error(const std::string& what)
-      : std::runtime_error(what)
+      : Tlv::Error(what)
     {
     }
   };
diff --git a/src/face.cpp b/src/face.cpp
index 3e5a4b1..5e9cd3c 100644
--- a/src/face.cpp
+++ b/src/face.cpp
@@ -77,11 +77,11 @@
     {
       protocol = m_config.getParsedConfiguration().get<std::string>("protocol");
     }
-  catch (const boost::property_tree::ptree_bad_path& error)
+  catch (boost::property_tree::ptree_bad_path& error)
     {
       // protocol not specified
     }
-  catch (const boost::property_tree::ptree_bad_data& error)
+  catch (boost::property_tree::ptree_bad_data& error)
     {
       throw ConfigFile::Error(error.what());
     }
@@ -276,7 +276,7 @@
       // break
       m_ioService->reset();
     }
-  catch (const std::exception&)
+  catch (std::exception&)
     {
       m_ioService->reset();
       m_pendingInterestTable.clear();
diff --git a/src/key-locator.hpp b/src/key-locator.hpp
index 14a1b5e..f0700e2 100644
--- a/src/key-locator.hpp
+++ b/src/key-locator.hpp
@@ -13,7 +13,8 @@
 
 namespace ndn {
 
-class KeyLocator {
+class KeyLocator
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/management/ndnd-face-instance.hpp b/src/management/ndnd-face-instance.hpp
index 530f10d..24f90f9 100644
--- a/src/management/ndnd-face-instance.hpp
+++ b/src/management/ndnd-face-instance.hpp
@@ -17,7 +17,8 @@
 /**
  * An FaceInstance holds an action and  Name prefix and other fields for an forwarding entry.
  */
-class FaceInstance {
+class FaceInstance
+{
 public:
   FaceInstance(const std::string& action,
                int64_t     faceId,
diff --git a/src/management/ndnd-forwarding-entry.hpp b/src/management/ndnd-forwarding-entry.hpp
index a084964..e654ff4 100644
--- a/src/management/ndnd-forwarding-entry.hpp
+++ b/src/management/ndnd-forwarding-entry.hpp
@@ -19,7 +19,8 @@
 /**
  * An ForwardingEntry holds an action and  Name prefix and other fields for an forwarding entry.
  */
-class ForwardingEntry {
+class ForwardingEntry
+{
 public:
   ForwardingEntry(const std::string& action,
                   const Name& prefix,
diff --git a/src/management/ndnd-forwarding-flags.hpp b/src/management/ndnd-forwarding-flags.hpp
index 803dabc..36a565f 100644
--- a/src/management/ndnd-forwarding-flags.hpp
+++ b/src/management/ndnd-forwarding-flags.hpp
@@ -19,7 +19,8 @@
  * a registered prefix.  We use a separate ForwardingFlags object to retain future compatibility if the daemon forwarding
  * bits are changed, amended or deprecated.
  */
-class ForwardingFlags {
+class ForwardingFlags
+{
 public:
   /**
    * Create a new ForwardingFlags with "active" and "childInherit" set and all other flags cleared.
diff --git a/src/management/ndnd-status-response.hpp b/src/management/ndnd-status-response.hpp
index 23597b9..2229a1d 100644
--- a/src/management/ndnd-status-response.hpp
+++ b/src/management/ndnd-status-response.hpp
@@ -13,7 +13,8 @@
 namespace ndn {
 namespace ndnd {
 
-class StatusResponse {
+class StatusResponse
+{
 public:
   StatusResponse()
     : code_(0)
diff --git a/src/management/nfd-control-response.hpp b/src/management/nfd-control-response.hpp
index a4a5ae3..3c2a06d 100644
--- a/src/management/nfd-control-response.hpp
+++ b/src/management/nfd-control-response.hpp
@@ -18,7 +18,8 @@
  *
  * @see http://redmine.named-data.net/projects/nfd/wiki/ControlCommand
  */
-class ControlResponse {
+class ControlResponse
+{
 public:
   class Error : public Tlv::Error
   {
diff --git a/src/management/nrd-prefix-reg-options.hpp b/src/management/nrd-prefix-reg-options.hpp
index ea8ca4d..8f2a0e5 100644
--- a/src/management/nrd-prefix-reg-options.hpp
+++ b/src/management/nrd-prefix-reg-options.hpp
@@ -25,7 +25,8 @@
  * @see http://redmine.named-data.net/projects/nrd/wiki/NRD_Prefix_Registration_protocol
  * @deprecated use NFD RIB Management
  */
-class PrefixRegOptions {
+class PrefixRegOptions
+{
 public:
   class Error : public Tlv::Error
   {
diff --git a/src/meta-info.hpp b/src/meta-info.hpp
index 4153911..03600cf 100644
--- a/src/meta-info.hpp
+++ b/src/meta-info.hpp
@@ -14,7 +14,8 @@
 /**
  * An MetaInfo holds the meta info which is signed inside the data packet.
  */
-class MetaInfo {
+class MetaInfo
+{
 public:
   enum {
     TYPE_DEFAULT = 0,
diff --git a/src/name-component.hpp b/src/name-component.hpp
index 5e5cb09..ff13346 100644
--- a/src/name-component.hpp
+++ b/src/name-component.hpp
@@ -25,14 +25,14 @@
 {
 public:
   /**
-   * @brief Error that can be thrown from the block
+   * @brief Error that can be thrown from name::Component
    */
-  class Error : public std::runtime_error
+  class Error : public Block::Error
   {
   public:
     explicit
     Error(const std::string& what)
-      : std::runtime_error(what)
+      : Block::Error(what)
     {
     }
   };
diff --git a/src/name.hpp b/src/name.hpp
index 03030f0..3a0cc52 100644
--- a/src/name.hpp
+++ b/src/name.hpp
@@ -23,13 +23,18 @@
 /**
  * A Name holds an array of Name::Component and represents an NDN name.
  */
-class Name : public ptr_lib::enable_shared_from_this<Name> {
+class Name : public ptr_lib::enable_shared_from_this<Name>
+{
 public:
-  /// @brief Error that can be thrown from the block
-  class Error : public name::Component::Error {
+  /// @brief Error that can be thrown from Name
+  class Error : public name::Component::Error
+  {
   public:
+    explicit
     Error(const std::string& what)
-      : name::Component::Error(what) {}
+      : name::Component::Error(what)
+    {
+    }
   };
 
   typedef name::Component Component;
diff --git a/src/security/certificate-extension.hpp b/src/security/certificate-extension.hpp
index a1aa5b6..83653ee 100644
--- a/src/security/certificate-extension.hpp
+++ b/src/security/certificate-extension.hpp
@@ -13,7 +13,9 @@
 #include "../encoding/buffer.hpp"
 #include "../encoding/oid.hpp"
 
-namespace CryptoPP { class BufferedTransformation; }
+namespace CryptoPP {
+class BufferedTransformation;
+}
 
 namespace ndn {
 
diff --git a/src/security/certificate-subject-description.hpp b/src/security/certificate-subject-description.hpp
index 7665a3f..e8732f0 100644
--- a/src/security/certificate-subject-description.hpp
+++ b/src/security/certificate-subject-description.hpp
@@ -12,14 +12,17 @@
 #include "../common.hpp"
 #include "../encoding/oid.hpp"
 
-namespace CryptoPP { class BufferedTransformation; }
+namespace CryptoPP {
+class BufferedTransformation;
+}
 
 namespace ndn {
 
 /**
  * A CertificateSubjectDescription represents the SubjectDescription entry in a Certificate.
  */
-class CertificateSubjectDescription {
+class CertificateSubjectDescription
+{
 public:
   CertificateSubjectDescription(CryptoPP::BufferedTransformation& in)
   {
diff --git a/src/security/certificate.hpp b/src/security/certificate.hpp
index dc96879..157b878 100644
--- a/src/security/certificate.hpp
+++ b/src/security/certificate.hpp
@@ -17,7 +17,8 @@
 
 namespace ndn {
 
-class Certificate : public Data {
+class Certificate : public Data
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/security/conf/checker.hpp b/src/security/conf/checker.hpp
index 72ae726..6955dfe 100644
--- a/src/security/conf/checker.hpp
+++ b/src/security/conf/checker.hpp
@@ -101,16 +101,16 @@
                             interestName[INTEREST_SIG_VALUE].blockFromValue());
         return check(interest, signature, onValidated, onValidationFailed);
       }
-    catch (const Tlv::Error& e)
-      {
-        onValidationFailed(interest.shared_from_this(), "Cannot decode signature related TLVs");
-        return -1;
-      }
-    catch (const Signature::Error& e)
+    catch (Signature::Error& e)
       {
         onValidationFailed(interest.shared_from_this(), "Invalid signature");
         return -1;
       }
+    catch (Tlv::Error& e)
+      {
+        onValidationFailed(interest.shared_from_this(), "Cannot decode signature related TLVs");
+        return -1;
+      }
   }
 
 private:
@@ -147,7 +147,7 @@
                   return -1;
                 }
             }
-          catch (const SignatureSha256WithRsa::Error& e)
+          catch (SignatureSha256WithRsa::Error& e)
             {
               onValidationFailed(packet.shared_from_this(),
                                  "Cannot decode Sha256WithRsa signature!");
@@ -221,16 +221,16 @@
                             interestName[INTEREST_SIG_VALUE].blockFromValue());
         return check(interest, signature, onValidated, onValidationFailed);
       }
-    catch (const Tlv::Error& e)
-      {
-        onValidationFailed(interest.shared_from_this(), "Cannot decode signature related TLVs");
-        return -1;
-      }
-    catch (const Signature::Error& e)
+    catch (Signature::Error& e)
       {
         onValidationFailed(interest.shared_from_this(), "Invalid signature");
         return -1;
       }
+    catch (Tlv::Error& e)
+      {
+        onValidationFailed(interest.shared_from_this(), "Cannot decode signature related TLVs");
+        return -1;
+      }
   }
 
 private:
@@ -280,13 +280,13 @@
                   return -1;
                 }
             }
-          catch (const KeyLocator::Error& e)
+          catch (KeyLocator::Error& e)
             {
               onValidationFailed(packet.shared_from_this(),
                                  "KeyLocator does not have name!");
               return -1;
             }
-          catch (const SignatureSha256WithRsa::Error& e)
+          catch (SignatureSha256WithRsa::Error& e)
             {
               onValidationFailed(packet.shared_from_this(),
                                  "Cannot decode signature!");
diff --git a/src/security/conf/filter.hpp b/src/security/conf/filter.hpp
index 7d5b833..4145222 100644
--- a/src/security/conf/filter.hpp
+++ b/src/security/conf/filter.hpp
@@ -207,7 +207,7 @@
           {
             return shared_ptr<RegexNameFilter>(new RegexNameFilter(regexString));
           }
-        catch (const Regex::Error& e)
+        catch (Regex::Error& e)
           {
             throw Error("Wrong filter.regex: " + regexString);
           }
diff --git a/src/security/conf/key-locator-checker.hpp b/src/security/conf/key-locator-checker.hpp
index 5785c59..e040d80 100644
--- a/src/security/conf/key-locator-checker.hpp
+++ b/src/security/conf/key-locator-checker.hpp
@@ -107,7 +107,7 @@
         failInfo = "KeyLocatorChecker failed!";
         return false;
       }
-    catch (const KeyLocator::Error& e)
+    catch (KeyLocator::Error& e)
       {
         failInfo = "KeyLocator does not have name";
         return false;
@@ -141,7 +141,7 @@
         failInfo = "KeyLocatorChecker failed!";
         return false;
       }
-    catch (const KeyLocator::Error& e)
+    catch (KeyLocator::Error& e)
       {
         failInfo = "KeyLocator does not have name";
         return false;
@@ -182,7 +182,7 @@
         failInfo = "KeyLocatorChecker failed!";
         return false;
       }
-    catch (const KeyLocator::Error& e)
+    catch (KeyLocator::Error& e)
       {
         failInfo = "KeyLocator does not have name";
         return false;
@@ -277,7 +277,7 @@
             return shared_ptr<RegexKeyLocatorNameChecker>
               (new RegexKeyLocatorNameChecker(regexString));
           }
-        catch (const Regex::Error& e)
+        catch (Regex::Error& e)
           {
             throw Error("Invalid checker.key-locator.regex: " + regexString);
           }
@@ -344,7 +344,7 @@
                                               kRegex, kExpand,
                                               relation));
           }
-        catch (const Regex::Error& e)
+        catch (Regex::Error& e)
           {
             throw Error("Invalid regex for key-locator.hyper-relation");
           }
diff --git a/src/security/encryption-manager.hpp b/src/security/encryption-manager.hpp
index a6f319b..f4f43b5 100644
--- a/src/security/encryption-manager.hpp
+++ b/src/security/encryption-manager.hpp
@@ -13,7 +13,8 @@
 
 namespace ndn {
 
-class EncryptionManager {
+class EncryptionManager
+{
 public:
   virtual ~EncryptionManager()
   {
diff --git a/src/security/public-key.hpp b/src/security/public-key.hpp
index 7774755..4a8f16a 100644
--- a/src/security/public-key.hpp
+++ b/src/security/public-key.hpp
@@ -16,7 +16,8 @@
 
 namespace ndn {
 
-class PublicKey {
+class PublicKey
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/security/sec-public-info-memory.hpp b/src/security/sec-public-info-memory.hpp
index 2ecdc43..4cbceac 100644
--- a/src/security/sec-public-info-memory.hpp
+++ b/src/security/sec-public-info-memory.hpp
@@ -17,7 +17,8 @@
  * @brief SecPublicInfoMemory extends SecPublicInfo and implements its methods to store identity,
  *        public key and certificate objects in memory.
  */
-class SecPublicInfoMemory : public SecPublicInfo {
+class SecPublicInfoMemory : public SecPublicInfo
+{
 public:
   class Error : public SecPublicInfo::Error
   {
@@ -104,7 +105,8 @@
 
 
 private:
-  class KeyRecord {
+  class KeyRecord
+  {
   public:
     KeyRecord(KeyType keyType, const PublicKey& key)
     : m_keyType(keyType), m_key(key)
diff --git a/src/security/sec-public-info-sqlite3.hpp b/src/security/sec-public-info-sqlite3.hpp
index 6241817..4f5115f 100644
--- a/src/security/sec-public-info-sqlite3.hpp
+++ b/src/security/sec-public-info-sqlite3.hpp
@@ -16,7 +16,8 @@
 
 namespace ndn {
 
-class SecPublicInfoSqlite3 : public SecPublicInfo {
+class SecPublicInfoSqlite3 : public SecPublicInfo
+{
 public:
   class Error : public SecPublicInfo::Error
   {
diff --git a/src/security/sec-public-info.hpp b/src/security/sec-public-info.hpp
index 99b4f57..ee32d05 100644
--- a/src/security/sec-public-info.hpp
+++ b/src/security/sec-public-info.hpp
@@ -23,7 +23,8 @@
  * It specify interfaces related to public information, such as identity, public keys and
  * certificates.
  */
-class SecPublicInfo {
+class SecPublicInfo
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/security/sec-tpm-file.cpp b/src/security/sec-tpm-file.cpp
index 5238ca4..ba3cca8 100644
--- a/src/security/sec-tpm-file.cpp
+++ b/src/security/sec-tpm-file.cpp
@@ -25,7 +25,8 @@
 
 namespace ndn {
 
-class SecTpmFile::Impl {
+class SecTpmFile::Impl
+{
 public:
   Impl(const string& dir)
   {
@@ -123,7 +124,7 @@
           throw Error("Unsupported key type!");
         }
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       throw Error(e.what());
     }
@@ -158,7 +159,7 @@
                  true,
                  new Base64Decoder(new FileSink(os)));
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       throw Error(e.what());
     }
@@ -191,7 +192,7 @@
                    new Base64Encoder(new FileSink(keyFileName.c_str())));
       return true;
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
@@ -211,7 +212,7 @@
                    new Base64Encoder(new FileSink(keyFileName.c_str())));
       return true;
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
@@ -258,7 +259,7 @@
           throw Error("Unsupported digest algorithm!");
         }
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       throw Error(e.what());
     }
@@ -294,7 +295,7 @@
 
   //       return os.buf();
   //     }
-  //     catch (const CryptoPP::Exception& e){
+  //     catch (CryptoPP::Exception& e){
   //       throw Error(e.what());
   //     }
   //   }
@@ -321,7 +322,7 @@
   //     // 	StringSource(data, dataLength, true, new StreamTransformationFilter(decryptor,new FileSink(os)));
   //     // 	return os.buf();
 
-  //     // }catch (const CryptoPP::Exception& e){
+  //     // }catch (CryptoPP::Exception& e){
   //     // 	throw Error(e.what());
   //     // }
   //   }
@@ -357,7 +358,7 @@
   //         StringSource(data, dataLength, true, new PK_EncryptorFilter(rng, encryptor, new FileSink(os)));
   //         return os.buf();
   //       }
-  //     catch (const CryptoPP::Exception& e){
+  //     catch (CryptoPP::Exception& e){
   //       throw Error(e.what());
   //     }
   //   }
@@ -383,7 +384,7 @@
   //     // 	OBufferStream os;
   //     // 	StringSource(data, dataLength, true, new StreamTransformationFilter(encryptor, new FileSink(os)));
   //     // 	return os.buf();
-  //     // }catch (const CryptoPP::Exception& e){
+  //     // }catch (CryptoPP::Exception& e){
   //     // 	throw Error(e.what());
   //     // }
   //   }
@@ -420,7 +421,7 @@
   //   default:
   //     throw Error("Unsupported symmetric key type!");
   //   }
-  // }catch (const CryptoPP::Exception& e){
+  // }catch (CryptoPP::Exception& e){
   //   throw Error(e.what());
   // }
 }
@@ -462,7 +463,7 @@
       rng.GenerateBlock(res, size);
       return true;
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
diff --git a/src/security/sec-tpm-memory.cpp b/src/security/sec-tpm-memory.cpp
index 3475aa4..393a217 100644
--- a/src/security/sec-tpm-memory.cpp
+++ b/src/security/sec-tpm-memory.cpp
@@ -20,7 +20,8 @@
 /**
  * RsaPrivateKey is a simple class to hold an RSA private key.
  */
-class SecTpmMemory::RsaPrivateKey {
+class SecTpmMemory::RsaPrivateKey
+{
 public:
   RsaPrivateKey(const uint8_t* keyDer, size_t keyDerLength)
   {
@@ -175,7 +176,7 @@
       rng.GenerateBlock(res, size);
       return true;
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
diff --git a/src/security/sec-tpm-memory.hpp b/src/security/sec-tpm-memory.hpp
index 61b1c8a..eb1613d 100644
--- a/src/security/sec-tpm-memory.hpp
+++ b/src/security/sec-tpm-memory.hpp
@@ -20,7 +20,8 @@
  *
  * You should initialize by calling setKeyPairForKeyName.
  */
-class SecTpmMemory : public SecTpm {
+class SecTpmMemory : public SecTpm
+{
 public:
   class Error : public SecTpm::Error
   {
diff --git a/src/security/sec-tpm-osx.cpp b/src/security/sec-tpm-osx.cpp
index d06cefe..fd21439 100644
--- a/src/security/sec-tpm-osx.cpp
+++ b/src/security/sec-tpm-osx.cpp
@@ -28,12 +28,14 @@
 
 namespace ndn {
 
-class SecTpmOsx::Impl {
+class SecTpmOsx::Impl
+{
 public:
   Impl()
     : m_passwordSet(false)
     , m_inTerminal(false)
-  {}
+  {
+  }
 
   /**
    * @brief Convert NDN name of a key to internal name of the key.
diff --git a/src/security/sec-tpm-osx.hpp b/src/security/sec-tpm-osx.hpp
index d6637ef..1a5bd1f 100644
--- a/src/security/sec-tpm-osx.hpp
+++ b/src/security/sec-tpm-osx.hpp
@@ -13,7 +13,8 @@
 
 namespace ndn {
 
-class SecTpmOsx : public SecTpm {
+class SecTpmOsx : public SecTpm
+{
 public:
   class Error : public SecTpm::Error
   {
diff --git a/src/security/sec-tpm.hpp b/src/security/sec-tpm.hpp
index 15f1770..14b5756 100644
--- a/src/security/sec-tpm.hpp
+++ b/src/security/sec-tpm.hpp
@@ -22,7 +22,8 @@
  *
  * It specifies the interfaces of private/secret key related operations.
  */
-class SecTpm {
+class SecTpm
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/security/signature-sha256-with-rsa.hpp b/src/security/signature-sha256-with-rsa.hpp
index 7e19a1e..f809709 100644
--- a/src/security/signature-sha256-with-rsa.hpp
+++ b/src/security/signature-sha256-with-rsa.hpp
@@ -15,8 +15,19 @@
 /**
  * Representing of SHA256-with-RSA signature in a data packet.
  */
-class SignatureSha256WithRsa : public Signature {
+class SignatureSha256WithRsa : public Signature
+{
 public:
+  class Error : public Signature::Error
+  {
+  public:
+    explicit
+    Error(const std::string& what)
+      : Signature::Error(what)
+    {
+    }
+  };
+
   SignatureSha256WithRsa()
   {
     m_info = Block(Tlv::SignatureInfo);
@@ -30,7 +41,7 @@
     : Signature(signature)
   {
     if (getType() != Signature::Sha256WithRsa)
-      throw Signature::Error("Incorrect signature type");
+      throw Error("Incorrect signature type");
 
     m_info.parse();
     Block::element_const_iterator i = m_info.find(Tlv::KeyLocator);
diff --git a/src/security/signature-sha256.hpp b/src/security/signature-sha256.hpp
index 8ef37a8..9200ac5 100644
--- a/src/security/signature-sha256.hpp
+++ b/src/security/signature-sha256.hpp
@@ -15,8 +15,19 @@
 /**
  * Representing of SHA256 signature in a data packet.
  */
-class SignatureSha256 : public Signature {
+class SignatureSha256 : public Signature
+{
 public:
+  class Error : public Signature::Error
+  {
+  public:
+    explicit
+    Error(const std::string& what)
+      : Signature::Error(what)
+    {
+    }
+  };
+
   SignatureSha256()
   {
     m_info = Block(Tlv::SignatureInfo);
@@ -29,7 +40,7 @@
     : Signature(signature)
   {
     if (getType() != Signature::Sha256)
-      throw Signature::Error("Incorrect signature type");
+      throw Error("Incorrect signature type");
   }
 };
 
diff --git a/src/security/validation-request.hpp b/src/security/validation-request.hpp
index 8846636..b525c27 100644
--- a/src/security/validation-request.hpp
+++ b/src/security/validation-request.hpp
@@ -27,7 +27,8 @@
                       const std::string&)> OnDataValidationFailed;
 
 
-class ValidationRequest {
+class ValidationRequest
+{
 public:
   ValidationRequest(const Interest& interest,
                     const OnDataValidated& onValidated,
diff --git a/src/security/validator-config.cpp b/src/security/validator-config.cpp
index 77d3354..4b430ce 100644
--- a/src/security/validator-config.cpp
+++ b/src/security/validator-config.cpp
@@ -70,7 +70,7 @@
     {
       boost::property_tree::read_info(input, tree);
     }
-  catch (const boost::property_tree::info_parser_error& error)
+  catch (boost::property_tree::info_parser_error& error)
     {
       std::stringstream msg;
       msg << "Failed to parse configuration file";
diff --git a/src/security/validator-null.hpp b/src/security/validator-null.hpp
index f389d4c..1bb6d01 100644
--- a/src/security/validator-null.hpp
+++ b/src/security/validator-null.hpp
@@ -13,7 +13,8 @@
 
 namespace ndn {
 
-class ValidatorNull : public Validator {
+class ValidatorNull : public Validator
+{
 public:
   virtual
   ~ValidatorNull()
diff --git a/src/security/validator-regex.cpp b/src/security/validator-regex.cpp
index 1eea45e..e9558c6 100644
--- a/src/security/validator-regex.cpp
+++ b/src/security/validator-regex.cpp
@@ -152,13 +152,13 @@
                   return;
                 }
             }
-          catch (const SignatureSha256WithRsa::Error& e)
+          catch (SignatureSha256WithRsa::Error& e)
             {
               return onValidationFailed(data.shared_from_this(),
                                         "Not SignatureSha256WithRsa signature: " +
                                         data.getName().toUri());
             }
-          catch (const KeyLocator::Error& e)
+          catch (KeyLocator::Error& e)
             {
               return onValidationFailed(data.shared_from_this(),
                                         "Key Locator is not a name: " +
diff --git a/src/security/validator.cpp b/src/security/validator.cpp
index 338ef9f..7f97926 100644
--- a/src/security/validator.cpp
+++ b/src/security/validator.cpp
@@ -142,7 +142,7 @@
           }
         }
     }
-  catch (const Signature::Error& e)
+  catch (Signature::Error& e)
     {
       return false;
     }
@@ -180,11 +180,11 @@
           }
         }
     }
-  catch (const Signature::Error& e)
+  catch (Signature::Error& e)
     {
       return false;
     }
-  catch (const Block::Error& e)
+  catch (Block::Error& e)
     {
       return false;
     }
@@ -209,7 +209,7 @@
           }
         }
     }
-  catch (const Signature::Error& e)
+  catch (Signature::Error& e)
     {
       return false;
     }
@@ -237,7 +237,7 @@
                                     sig.getValue().value(),
                                     sig.getValue().value_size());
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
@@ -264,7 +264,7 @@
       else
         return false;
     }
-  catch (const CryptoPP::Exception& e)
+  catch (CryptoPP::Exception& e)
     {
       return false;
     }
diff --git a/src/security/validator.hpp b/src/security/validator.hpp
index 43ab01a..38a8db2 100644
--- a/src/security/validator.hpp
+++ b/src/security/validator.hpp
@@ -24,7 +24,8 @@
  *
  * The Validator class provides the interfaces for packet validation.
  */
-class Validator {
+class Validator
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/signature.hpp b/src/signature.hpp
index 8a20baa..3d3c4c9 100644
--- a/src/signature.hpp
+++ b/src/signature.hpp
@@ -12,14 +12,15 @@
 /**
  * A Signature is storage for the signature-related information (info and value) in a Data packet.
  */
-class Signature {
+class Signature
+{
 public:
-  class Error : public std::runtime_error
+  class Error : public Tlv::Error
   {
   public:
     explicit
     Error(const std::string& what)
-      : std::runtime_error(what)
+      : Tlv::Error(what)
     {
     }
   };
diff --git a/src/transport/tcp-transport.hpp b/src/transport/tcp-transport.hpp
index 6795580..db90ae4 100644
--- a/src/transport/tcp-transport.hpp
+++ b/src/transport/tcp-transport.hpp
@@ -26,11 +26,11 @@
   ~TcpTransport();
 
   // from Transport
-  virtual void 
+  virtual void
   connect(boost::asio::io_service& ioService,
           const ReceiveCallback& receiveCallback);
-  
-  virtual void 
+
+  virtual void
   close();
 
   virtual void
@@ -39,10 +39,10 @@
   virtual void
   resume();
 
-  virtual void 
+  virtual void
   send(const Block& wire);
 
-  virtual void 
+  virtual void
   send(const Block& header, const Block& payload);
 
 private:
diff --git a/src/transport/transport.hpp b/src/transport/transport.hpp
index 08740fb..eda9521 100644
--- a/src/transport/transport.hpp
+++ b/src/transport/transport.hpp
@@ -12,7 +12,8 @@
 
 namespace ndn {
 
-class Transport {
+class Transport
+{
 public:
   class Error : public std::runtime_error
   {
diff --git a/src/transport/unix-transport.cpp b/src/transport/unix-transport.cpp
index ad6db2c..4dc636a 100644
--- a/src/transport/unix-transport.cpp
+++ b/src/transport/unix-transport.cpp
@@ -30,11 +30,11 @@
     {
       return parsed.get<std::string>("unix_socket");
     }
-  catch (const boost::property_tree::ptree_bad_path& error)
+  catch (boost::property_tree::ptree_bad_path& error)
     {
       // unix_socket not present, continue
     }
-  catch (const boost::property_tree::ptree_bad_data& error)
+  catch (boost::property_tree::ptree_bad_data& error)
     {
       throw ConfigFile::Error(error.what());
     }
diff --git a/src/util/command-interest-validator.hpp b/src/util/command-interest-validator.hpp
index 07e164f..c543549 100644
--- a/src/util/command-interest-validator.hpp
+++ b/src/util/command-interest-validator.hpp
@@ -182,21 +182,21 @@
           timestampIt->second = interestTime;
         }
     }
-  catch (const Tlv::Error& e)
-    {
-      return onValidationFailed(interest.shared_from_this(),
-                                "Cannot decode signature related TLVs");
-    }
-  catch (const Signature::Error& e)
+  catch (Signature::Error& e)
     {
       return onValidationFailed(interest.shared_from_this(),
                                 "No valid signature");
     }
-  catch (const IdentityCertificate::Error& e)
+  catch (IdentityCertificate::Error& e)
     {
       return onValidationFailed(interest.shared_from_this(),
                                 "Cannot locate the signing key");
     }
+  catch (Tlv::Error& e)
+    {
+      return onValidationFailed(interest.shared_from_this(),
+                                "Cannot decode signature related TLVs");
+    }
 
   return onValidated(interest.shared_from_this());
 }
diff --git a/src/util/config-file.cpp b/src/util/config-file.cpp
index 031df25..c80ddc6 100644
--- a/src/util/config-file.cpp
+++ b/src/util/config-file.cpp
@@ -108,7 +108,7 @@
     {
       boost::property_tree::read_ini(m_input, m_config);
     }
-  catch (const boost::property_tree::ini_parser_error& error)
+  catch (boost::property_tree::ini_parser_error& error)
     {
       std::stringstream msg;
       msg << "Failed to parse configuration file";
@@ -120,4 +120,3 @@
 }
 
 }
-
diff --git a/src/util/io.hpp b/src/util/io.hpp
index ff6852b..0bb929b 100644
--- a/src/util/io.hpp
+++ b/src/util/io.hpp
@@ -76,7 +76,7 @@
     {
       return shared_ptr<T>();
     }
-  catch (Block::Error& e)
+  catch (Tlv::Error& e)
     {
       return shared_ptr<T>();
     }
@@ -134,7 +134,7 @@
     {
       throw Error(e.what());
     }
-  catch (Block::Error& e)
+  catch (Tlv::Error& e)
     {
       throw Error(e.what());
     }
diff --git a/src/util/regex/regex-component-set-matcher.hpp b/src/util/regex/regex-component-set-matcher.hpp
index 5aed58f..b8c9845 100644
--- a/src/util/regex/regex-component-set-matcher.hpp
+++ b/src/util/regex/regex-component-set-matcher.hpp
@@ -15,7 +15,8 @@
 
 namespace ndn {
 
-class RegexComponentSetMatcher : public RegexMatcher {
+class RegexComponentSetMatcher : public RegexMatcher
+{
 
 public:
   /**