diff --git a/src/ca-module.cpp b/src/ca-module.cpp
index f2e825a..2b3c500 100644
--- a/src/ca-module.cpp
+++ b/src/ca-module.cpp
@@ -19,14 +19,14 @@
  */
 
 #include "ca-module.hpp"
-#include "protocol-detail/crypto-helper.hpp"
+#include "detail/crypto-helper.hpp"
 #include "identity-challenge/challenge-module.hpp"
 #include "name-assignments/assignment-funcs.hpp"
-#include "protocol-detail/challenge-encoder.hpp"
-#include "protocol-detail/error-encoder.hpp"
-#include "protocol-detail/info-encoder.hpp"
-#include "protocol-detail/new-renew-revoke-encoder.hpp"
-#include "protocol-detail/probe-encoder.hpp"
+#include "detail/challenge-encoder.hpp"
+#include "detail/error-encoder.hpp"
+#include "detail/info-encoder.hpp"
+#include "detail/new-renew-revoke-encoder.hpp"
+#include "detail/probe-encoder.hpp"
 #include <ndn-cxx/metadata-object.hpp>
 #include <ndn-cxx/security/signing-helpers.hpp>
 #include <ndn-cxx/security/verification-helpers.hpp>
diff --git a/src/ca-module.hpp b/src/ca-module.hpp
index 3fb79cb..d29f49b 100644
--- a/src/ca-module.hpp
+++ b/src/ca-module.hpp
@@ -22,8 +22,8 @@
 #define NDNCERT_CA_MODULE_HPP
 
 #include "configuration.hpp"
-#include "protocol-detail/crypto-helper.hpp"
-#include "ca-detail/ca-storage.hpp"
+#include "detail/crypto-helper.hpp"
+#include "detail/ca-storage.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/configuration.hpp b/src/configuration.hpp
index 87b115a..50d2a8b 100644
--- a/src/configuration.hpp
+++ b/src/configuration.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_CONFIGURATION_HPP
 #define NDNCERT_CONFIGURATION_HPP
 
-#include "ca-detail/ca-state.hpp"
+#include "detail/ca-state.hpp"
 #include "name-assignments/assignment-funcs.hpp"
 
 namespace ndn {
diff --git a/src/ca-detail/ca-memory.cpp b/src/detail/ca-memory.cpp
similarity index 99%
rename from src/ca-detail/ca-memory.cpp
rename to src/detail/ca-memory.cpp
index 206f431..b647dba 100644
--- a/src/ca-detail/ca-memory.cpp
+++ b/src/detail/ca-memory.cpp
@@ -19,7 +19,6 @@
  */
 
 #include "ca-memory.hpp"
-
 #include <ndn-cxx/security/validation-policy.hpp>
 
 namespace ndn {
diff --git a/src/ca-detail/ca-memory.hpp b/src/detail/ca-memory.hpp
similarity index 100%
rename from src/ca-detail/ca-memory.hpp
rename to src/detail/ca-memory.hpp
diff --git a/src/ca-detail/ca-sqlite.cpp b/src/detail/ca-sqlite.cpp
similarity index 100%
rename from src/ca-detail/ca-sqlite.cpp
rename to src/detail/ca-sqlite.cpp
diff --git a/src/ca-detail/ca-sqlite.hpp b/src/detail/ca-sqlite.hpp
similarity index 100%
rename from src/ca-detail/ca-sqlite.hpp
rename to src/detail/ca-sqlite.hpp
diff --git a/src/ca-detail/ca-state.cpp b/src/detail/ca-state.cpp
similarity index 100%
rename from src/ca-detail/ca-state.cpp
rename to src/detail/ca-state.cpp
diff --git a/src/ca-detail/ca-state.hpp b/src/detail/ca-state.hpp
similarity index 98%
rename from src/ca-detail/ca-state.hpp
rename to src/detail/ca-state.hpp
index 4c99185..2204f1c 100644
--- a/src/ca-detail/ca-state.hpp
+++ b/src/detail/ca-state.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_CA_STATE_HPP
 #define NDNCERT_CA_STATE_HPP
 
-#include "protocol-detail/ndncert-common.hpp"
+#include "detail/ndncert-common.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/ca-detail/ca-storage.cpp b/src/detail/ca-storage.cpp
similarity index 97%
rename from src/ca-detail/ca-storage.cpp
rename to src/detail/ca-storage.cpp
index d0fac8f..a7195f6 100644
--- a/src/ca-detail/ca-storage.cpp
+++ b/src/detail/ca-storage.cpp
@@ -18,7 +18,7 @@
  * See AUTHORS.md for complete list of ndncert authors and contributors.
  */
 
-#include "ca-detail/ca-storage.hpp"
+#include "detail/ca-storage.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/ca-detail/ca-storage.hpp b/src/detail/ca-storage.hpp
similarity index 98%
rename from src/ca-detail/ca-storage.hpp
rename to src/detail/ca-storage.hpp
index e35af1a..70a0ac9 100644
--- a/src/ca-detail/ca-storage.hpp
+++ b/src/detail/ca-storage.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_CA_STORAGE_HPP
 #define NDNCERT_CA_STORAGE_HPP
 
-#include "ca-detail/ca-state.hpp"
+#include "detail/ca-state.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/protocol-detail/challenge-encoder.cpp b/src/detail/challenge-encoder.cpp
similarity index 100%
rename from src/protocol-detail/challenge-encoder.cpp
rename to src/detail/challenge-encoder.cpp
diff --git a/src/protocol-detail/challenge-encoder.hpp b/src/detail/challenge-encoder.hpp
similarity index 97%
rename from src/protocol-detail/challenge-encoder.hpp
rename to src/detail/challenge-encoder.hpp
index 60372f9..cce4108 100644
--- a/src/protocol-detail/challenge-encoder.hpp
+++ b/src/detail/challenge-encoder.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_PROTOCOL_DETAIL_CHALLENGE_STEP_HPP
 #define NDNCERT_PROTOCOL_DETAIL_CHALLENGE_STEP_HPP
 
-#include "../ca-detail/ca-state.hpp"
+#include "../detail/ca-state.hpp"
 #include "../requester-state.hpp"
 
 namespace ndn {
diff --git a/src/protocol-detail/crypto-helper.cpp b/src/detail/crypto-helper.cpp
similarity index 100%
rename from src/protocol-detail/crypto-helper.cpp
rename to src/detail/crypto-helper.cpp
diff --git a/src/protocol-detail/crypto-helper.hpp b/src/detail/crypto-helper.hpp
similarity index 100%
rename from src/protocol-detail/crypto-helper.hpp
rename to src/detail/crypto-helper.hpp
diff --git a/src/protocol-detail/error-encoder.cpp b/src/detail/error-encoder.cpp
similarity index 100%
rename from src/protocol-detail/error-encoder.cpp
rename to src/detail/error-encoder.cpp
diff --git a/src/protocol-detail/error-encoder.hpp b/src/detail/error-encoder.hpp
similarity index 100%
rename from src/protocol-detail/error-encoder.hpp
rename to src/detail/error-encoder.hpp
diff --git a/src/protocol-detail/info-encoder.cpp b/src/detail/info-encoder.cpp
similarity index 100%
rename from src/protocol-detail/info-encoder.cpp
rename to src/detail/info-encoder.cpp
diff --git a/src/protocol-detail/info-encoder.hpp b/src/detail/info-encoder.hpp
similarity index 100%
rename from src/protocol-detail/info-encoder.hpp
rename to src/detail/info-encoder.hpp
diff --git a/src/protocol-detail/ndncert-common.cpp b/src/detail/ndncert-common.cpp
similarity index 100%
rename from src/protocol-detail/ndncert-common.cpp
rename to src/detail/ndncert-common.cpp
diff --git a/src/protocol-detail/ndncert-common.hpp b/src/detail/ndncert-common.hpp
similarity index 100%
rename from src/protocol-detail/ndncert-common.hpp
rename to src/detail/ndncert-common.hpp
diff --git a/src/protocol-detail/new-renew-revoke-encoder.cpp b/src/detail/new-renew-revoke-encoder.cpp
similarity index 100%
rename from src/protocol-detail/new-renew-revoke-encoder.cpp
rename to src/detail/new-renew-revoke-encoder.cpp
diff --git a/src/protocol-detail/new-renew-revoke-encoder.hpp b/src/detail/new-renew-revoke-encoder.hpp
similarity index 97%
rename from src/protocol-detail/new-renew-revoke-encoder.hpp
rename to src/detail/new-renew-revoke-encoder.hpp
index 98e29c4..70e69aa 100644
--- a/src/protocol-detail/new-renew-revoke-encoder.hpp
+++ b/src/detail/new-renew-revoke-encoder.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_PROTOCOL_DETAIL_NEW_RENEW_REVOKE_ENCODER_HPP
 #define NDNCERT_PROTOCOL_DETAIL_NEW_RENEW_REVOKE_ENCODER_HPP
 
-#include "../ca-detail/ca-state.hpp"
+#include "../detail/ca-state.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/protocol-detail/probe-encoder.cpp b/src/detail/probe-encoder.cpp
similarity index 100%
rename from src/protocol-detail/probe-encoder.cpp
rename to src/detail/probe-encoder.cpp
diff --git a/src/protocol-detail/probe-encoder.hpp b/src/detail/probe-encoder.hpp
similarity index 100%
rename from src/protocol-detail/probe-encoder.hpp
rename to src/detail/probe-encoder.hpp
diff --git a/src/identity-challenge/challenge-module.hpp b/src/identity-challenge/challenge-module.hpp
index eabb19d..22c6a4c 100644
--- a/src/identity-challenge/challenge-module.hpp
+++ b/src/identity-challenge/challenge-module.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_CHALLENGE_MODULE_HPP
 #define NDNCERT_CHALLENGE_MODULE_HPP
 
-#include "ca-detail/ca-state.hpp"
+#include "detail/ca-state.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/name-assignments/assignment-funcs.hpp b/src/name-assignments/assignment-funcs.hpp
index a39bb82..355efdd 100644
--- a/src/name-assignments/assignment-funcs.hpp
+++ b/src/name-assignments/assignment-funcs.hpp
@@ -21,7 +21,7 @@
 #ifndef NDNCERT_ASSIGNMENT_FUNCS_HPP
 #define NDNCERT_ASSIGNMENT_FUNCS_HPP
 
-#include "../ca-detail/ca-state.hpp"
+#include "../detail/ca-state.hpp"
 
 namespace ndn {
 namespace ndncert {
diff --git a/src/requester-state.hpp b/src/requester-state.hpp
index 8a254c6..09c46ac 100644
--- a/src/requester-state.hpp
+++ b/src/requester-state.hpp
@@ -21,8 +21,8 @@
 #ifndef NDNCERT_REQUESTER_STATE_HPP
 #define NDNCERT_REQUESTER_STATE_HPP
 
-#include "protocol-detail/ndncert-common.hpp"
-#include "protocol-detail/crypto-helper.hpp"
+#include "detail/ndncert-common.hpp"
+#include "detail/crypto-helper.hpp"
 #include "configuration.hpp"
 
 namespace ndn {
diff --git a/src/requester.cpp b/src/requester.cpp
index 64ce59c..737d0cc 100644
--- a/src/requester.cpp
+++ b/src/requester.cpp
@@ -20,12 +20,12 @@
 
 #include "requester.hpp"
 #include "identity-challenge/challenge-module.hpp"
-#include "protocol-detail/crypto-helper.hpp"
-#include "protocol-detail/challenge-encoder.hpp"
-#include "protocol-detail/error-encoder.hpp"
-#include "protocol-detail/info-encoder.hpp"
-#include "protocol-detail/new-renew-revoke-encoder.hpp"
-#include "protocol-detail/probe-encoder.hpp"
+#include "detail/crypto-helper.hpp"
+#include "detail/challenge-encoder.hpp"
+#include "detail/error-encoder.hpp"
+#include "detail/info-encoder.hpp"
+#include "detail/new-renew-revoke-encoder.hpp"
+#include "detail/probe-encoder.hpp"
 #include <ndn-cxx/security/signing-helpers.hpp>
 #include <ndn-cxx/security/transform/base64-encode.hpp>
 #include <ndn-cxx/security/transform/buffer-source.hpp>