diff --git a/CMakeLists.txt b/CMakeLists.txt
index 83865a8..f7fc0dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,91 +3,47 @@ cmake_minimum_required(VERSION 3.7.0)
 project(cruft-crypto CXX)
 
 
-###############################################################################
-list (APPEND sources
-    fwd.hpp
-
-    hash/blake.cpp
-    hash/blake.hpp
-    hash/blake2.cpp
-    hash/blake2.hpp
-    hash/md2.cpp
-    hash/md2.hpp
-    hash/md4.cpp
-    hash/md4.hpp
-    hash/md5.cpp
-    hash/md5.hpp
-    hash/md6.cpp
-    hash/md6.hpp
-    hash/ripemd.cpp
-    hash/ripemd.hpp
-    hash/sha1.cpp
-    hash/sha1.hpp
-    hash/sha2.cpp
-    hash/sha2.hpp
-
-    hash/pbkdf2.cpp
-    hash/pbkdf2.hpp
-    hash/hmac.cpp
-    hash/hmac.hpp
-
-    hash/hotp.cpp
-    hash/hotp.hpp
-
-    stream/chacha.cpp
-    stream/chacha.hpp
-    stream/rabbit.cpp
-    stream/rabbit.hpp
-    stream/rc4.cpp
-    stream/rc4.hpp
-    stream/salsa.cpp
-    stream/salsa.hpp
-
-    block/rc5.cpp
-    block/rc5.hpp
-    block/rc6.cpp
-    block/rc6.hpp
-    block/speck.cpp
-    block/speck.hpp
-    block/tea.cpp
-    block/tea.hpp
-    block/xtea.cpp
-    block/xtea.hpp
-    block/xxtea.cpp
-    block/xxtea.hpp
+list (APPEND components
+    hash/blake
+    hash/blake2
+    hash/md2
+    hash/md4
+    hash/md5
+    hash/md6
+    hash/ripemd
+    hash/sha1
+    hash/sha2
+    hash/pbkdf2
+    hash/hmac
+    hash/hotp
+    stream/chacha
+    stream/rabbit
+    stream/rc4
+    stream/salsa
+    block/rc2
+    block/rc5
+    block/rc6
+    block/speck
+    block/tea
+    block/xtea
+    block/xxtea
 )
 
 
+###############################################################################
+list (APPEND sources fwd.hpp)
+foreach (c ${components})
+    list (APPEND sources "${c}.cpp" "${c}.hpp")
+endforeach()
+
+
 option (TESTS "enable unit testing" ON)
 
 if (TESTS)
     include (CTest)
     enable_testing ()
 
-    list (APPEND tests
-        hash/blake
-        hash/blake2
-        hash/md2
-        hash/md4
-        hash/md5
-        hash/md6
-        hash/ripemd
-        hash/sha1
-        hash/sha2
-
-        hash/hmac
-        hash/hotp
-
-        stream/rc4
-        stream/salsa
-
-        block/speck
-        block/tea
-        block/xtea
-        block/xxtea
-    )
-
-    foreach (t ${tests})
+    foreach (t ${components})
         string(REPLACE "/" "_" name "test/${t}")
         add_executable(crypto_${name} test/${t}.cpp)
         target_link_libraries(crypto_${name} PRIVATE cruft-crypto)
diff --git a/block/rc2.cpp b/block/rc2.cpp
new file mode 100644
index 0000000..1f378fa
--- /dev/null
+++ b/block/rc2.cpp
@@ -0,0 +1,13 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2018 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "rc2.hpp"
+
+
+///////////////////////////////////////////////////////////////////////////////
+
diff --git a/block/rc2.hpp b/block/rc2.hpp
new file mode 100644
index 0000000..21c878c
--- /dev/null
+++ b/block/rc2.hpp
@@ -0,0 +1,32 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2018 Danny Robson <danny@nerdcruft.net>
+ */
+
+#pragma once
+
+#include <cstddef>
+#include <array>
+
+#include <cruft/util/std.hpp>
+#include <cruft/util/view.hpp>
+
+namespace cruft::crypto::block {
+    /// An implementation of the RC2 block cipher (RFC2268)
+    class rc2 {
+    public:
+        using word_t = u16;
+        static constexpr auto block_size = sizeof (word_t) * 4;
+
+        explicit rc2 (cruft::view<u16 const*> key);
+
+        std::array<word_t,4> encrypt (std::array<word_t,4> src) const;
+        std::array<word_t,4> decrypt (std::array<word_t,4> src) const;
+
+    private:
+        std::array<u16,64> m_key;
+    };
+}
diff --git a/test/block/rc2.cpp b/test/block/rc2.cpp
new file mode 100644
index 0000000..f1c59fd
--- /dev/null
+++ b/test/block/rc2.cpp
@@ -0,0 +1,3 @@
+#include "block/rc2.hpp"
+
+int main () { }
\ No newline at end of file
diff --git a/test/block/rc5.cpp b/test/block/rc5.cpp
new file mode 100644
index 0000000..2b7b1eb
--- /dev/null
+++ b/test/block/rc5.cpp
@@ -0,0 +1 @@
+int main () { }
diff --git a/test/block/rc6.cpp b/test/block/rc6.cpp
new file mode 100644
index 0000000..2b7b1eb
--- /dev/null
+++ b/test/block/rc6.cpp
@@ -0,0 +1 @@
+int main () { }
diff --git a/test/hash/pbkdf2.cpp b/test/hash/pbkdf2.cpp
new file mode 100644
index 0000000..2b7b1eb
--- /dev/null
+++ b/test/hash/pbkdf2.cpp
@@ -0,0 +1 @@
+int main () { }
diff --git a/test/stream/chacha.cpp b/test/stream/chacha.cpp
new file mode 100644
index 0000000..2b7b1eb
--- /dev/null
+++ b/test/stream/chacha.cpp
@@ -0,0 +1 @@
+int main () { }
diff --git a/test/stream/rabbit.cpp b/test/stream/rabbit.cpp
new file mode 100644
index 0000000..2b7b1eb
--- /dev/null
+++ b/test/stream/rabbit.cpp
@@ -0,0 +1 @@
+int main () { }