diff --git a/src/security/v2/trust-anchor-group.cpp b/src/security/v2/trust-anchor-group.cpp
new file mode 100644
index 0000000..6b94951
--- /dev/null
+++ b/src/security/v2/trust-anchor-group.cpp
@@ -0,0 +1,143 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "trust-anchor-group.hpp"
+
+#include "util/io.hpp"
+#include "util/logger.hpp"
+
+#include <set>
+#include <boost/filesystem.hpp>
+#include <boost/range/adaptor/map.hpp>
+#include <boost/range/algorithm/copy.hpp>
+#include <boost/range/iterator_range.hpp>
+
+namespace ndn {
+namespace security {
+namespace v2 {
+
+NDN_LOG_INIT(ndn.security.v2.TrustAnchorGroup);
+
+namespace fs = boost::filesystem;
+
+TrustAnchorGroup::TrustAnchorGroup(CertContainerInterface& certContainer, const std::string& id)
+  : m_certs(certContainer)
+  , m_id(id)
+{
+}
+
+size_t
+TrustAnchorGroup::size() const
+{
+  return m_anchorNames.size();
+}
+
+void
+TrustAnchorGroup::refresh()
+{
+  // base method does nothing
+}
+
+//////////////
+
+StaticTrustAnchorGroup::StaticTrustAnchorGroup(CertContainerInterface& certContainer, const std::string& id)
+  : TrustAnchorGroup(certContainer, id)
+{
+}
+
+void
+StaticTrustAnchorGroup::add(Certificate&& cert)
+{
+  if (m_anchorNames.count(cert.getName()) != 0) {
+    return;
+  }
+
+  m_anchorNames.insert(cert.getName());
+  m_certs.add(std::move(cert));
+}
+
+void
+StaticTrustAnchorGroup::remove(const Name& certName)
+{
+  m_anchorNames.erase(certName);
+  m_certs.remove(certName);
+}
+
+/////////////
+
+DynamicTrustAnchorGroup::DynamicTrustAnchorGroup(CertContainerInterface& certContainer, const std::string& id,
+                                                 const boost::filesystem::path& path,
+                                                 time::nanoseconds refreshPeriod, bool isDir)
+  : TrustAnchorGroup(certContainer, id)
+  , m_isDir(isDir)
+  , m_path(path)
+  , m_refreshPeriod(refreshPeriod)
+{
+  if (refreshPeriod <= time::nanoseconds::zero()) {
+    BOOST_THROW_EXCEPTION(std::runtime_error("Refresh period for the dynamic group must be positive"));
+  }
+
+  refresh();
+}
+
+void
+DynamicTrustAnchorGroup::refresh()
+{
+  if (m_expireTime > time::steady_clock::now()) {
+    return;
+  }
+  m_expireTime = time::steady_clock::now() + m_refreshPeriod;
+  NDN_LOG_TRACE("Reloading dynamic trust anchor group");
+
+  std::set<Name> oldAnchorNames = m_anchorNames;
+
+  auto loadCert = [this, &oldAnchorNames] (const fs::path& file) {
+    auto cert = io::load<Certificate>(file.string());
+    if (cert != nullptr) {
+      if (m_anchorNames.count(cert->getName()) == 0) {
+        m_anchorNames.insert(cert->getName());
+        m_certs.add(std::move(*cert));
+      }
+      else {
+        oldAnchorNames.erase(cert->getName());
+      }
+    }
+  };
+
+  if (!m_isDir) {
+    loadCert(m_path);
+  }
+  else {
+    if (fs::exists(m_path)) {
+      std::for_each(fs::directory_iterator(m_path), fs::directory_iterator(), loadCert);
+    }
+  }
+
+  // remove old certs
+  for (const auto& oldAnchorName : oldAnchorNames) {
+    m_anchorNames.erase(oldAnchorName);
+    m_certs.remove(oldAnchorName);
+  }
+}
+
+} // namespace v2
+} // namespace security
+} // namespace ndn