diff --git a/Chaos/Cipher/Block/Mode/Ecb.hpp b/Chaos/Cipher/Block/Mode/Ecb.hpp
new file mode 100644
index 0000000..a5b2a45
--- /dev/null
+++ b/Chaos/Cipher/Block/Mode/Ecb.hpp
@@ -0,0 +1,113 @@
+#ifndef CHAOS_CIPHER_BLOCK_MODE_ECB_HPP
+#define CHAOS_CIPHER_BLOCK_MODE_ECB_HPP
+
+#include <cstddef>
+#include <cstdint>
+
+#include "Service/ChaosException.hpp"
+#include "Service/SeArray.hpp"
+
+namespace Chaos::Cipher::Block::Mode
+{
+
+template<typename CipherT, typename PadderT>
+class EcbMode
+{
+public:
+    class Encryptor
+    {
+    public:
+        Encryptor(const typename CipherT::Key & key)
+            : Encryptor_(key)
+            , BlockBytesPacked_(0)
+        { }
+
+        static constexpr uint64_t PredictMaxUpdateOutput(uint64_t in)
+        {
+            return in + CipherT::BlockSize - 1;
+        }
+
+        static constexpr uint64_t PredictMaxFinishOutput()
+        {
+            return CipherT::BlockSize;
+        }
+
+        template<typename OutputIt, typename InputIt>
+        uint64_t Update(OutputIt outBegin, OutputIt outEnd,
+                        InputIt inBegin, InputIt inEnd)
+        {
+            return UpdateImpl(outBegin, outEnd, inBegin, inEnd);
+        }
+
+        template<typename OutputIt>
+        uint64_t Finish(OutputIt outBegin, OutputIt outEnd)
+        {
+            PadderT::Pad(Block_.Begin() + BlockBytesPacked_, Block_.End());
+
+            Encryptor_.EncryptBlock(EncryptedBlock_.Begin(), EncryptedBlock_.End(),
+                                    Block_.Begin(), Block_.End());
+            EnsureCopy(outBegin, outEnd, EncryptedBlock_.Begin(), EncryptedBlock_.End());
+
+            return CipherT::BlockSize;
+        }
+
+    private:
+        typename CipherT::Encryptor Encryptor_;
+
+        uint64_t BlockBytesPacked_;
+        Service::SeArray<uint8_t, CipherT::BlockSize> Block_;
+
+        Service::SeArray<uint8_t, CipherT::BlockSize> EncryptedBlock_;
+
+        template<typename OutputIt, typename InputIt>
+        static OutputIt EnsureCopy(OutputIt outBegin, OutputIt outEnd,
+                                   InputIt inBegin, InputIt inEnd)
+        {
+            OutputIt out = outBegin;
+            InputIt in = inBegin;
+
+            for (; out != outEnd && in != inEnd; ++out, ++in)
+            {
+                *out = *in;
+            }
+
+            if (out == outEnd && in != inEnd)
+            {
+                throw Service::ChaosException("EcbMode<>::Encryptor: insufficient output "
+                                              "buffer size");
+            }
+
+            return out;
+        }
+
+        template<typename OutputIt, typename InputIt>
+        uint64_t UpdateImpl(OutputIt outBegin, OutputIt outEnd,
+                            InputIt inBegin, InputIt inEnd)
+        {
+            uint64_t written = 0;
+            OutputIt out = outBegin;
+
+            for (InputIt in = inBegin; in != inEnd; ++in)
+            {
+                Block_[BlockBytesPacked_++] = *in;
+
+                if (BlockBytesPacked_ == Block_.Size())
+                {
+                    BlockBytesPacked_ = 0;
+
+                    Encryptor_.EncryptBlock(EncryptedBlock_.Begin(), EncryptedBlock_.End(),
+                                            Block_.Begin(), Block_.End());
+                    out = EnsureCopy(out, outEnd, EncryptedBlock_.Begin(), EncryptedBlock_.End());
+
+                    written += CipherT::BlockSize;
+                }
+            }
+
+            return written;
+        }
+    };
+};
+
+} // namespace Chaos::Cipher::Block::Mode
+
+#endif // CHAOS_CIPHER_BLOCK_MODE_ECB_HPP
diff --git a/ChaosTests/CMakeLists.txt b/ChaosTests/CMakeLists.txt
index 2345b8d..0e401b4 100644
--- a/ChaosTests/CMakeLists.txt
+++ b/ChaosTests/CMakeLists.txt
@@ -18,6 +18,7 @@ set(ChaosTests_SOURCE Hash/Md4HasherTests.cpp
                       Cipher/Arc4GenTests.cpp
                       Cipher/Arc4CryptTests.cpp
                       Cipher/DesCryptTests.cpp
+                      Cipher/EcbModeTests.cpp
                       Padding/PadderPkcs7Tests.cpp
                       Padding/PadderIso7816Tests.cpp
                       Service/SeArrayTests.cpp
diff --git a/ChaosTests/Cipher/EcbModeTests.cpp b/ChaosTests/Cipher/EcbModeTests.cpp
new file mode 100644
index 0000000..d4a28f0
--- /dev/null
+++ b/ChaosTests/Cipher/EcbModeTests.cpp
@@ -0,0 +1,439 @@
+#include <gtest/gtest.h>
+
+#include <cstring>
+#include <cstdint>
+#include <iterator>
+#include <vector>
+
+#include "Cipher/Block/Mode/Ecb.hpp"
+#include "Cipher/Block/Des/DesCrypt.hpp"
+#include "Padding/PadderPkcs7.hpp"
+#include "Service/ChaosException.hpp"
+
+using namespace Chaos::Cipher::Block::Mode;
+using namespace Chaos::Cipher::Block;
+using namespace Chaos::Padding;
+
+TEST(EcbModeTests, EncryptTest)
+{
+    struct Helper
+    {
+        std::vector<uint8_t> operator()(const std::vector<uint8_t> & data,
+                                        const std::vector<uint8_t> & key)
+        {
+            Des::DesCrypt::Key desKey(key.begin(), key.end());
+            EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+            std::vector<uint8_t> out;
+            out.resize(enc.PredictMaxUpdateOutput(data.size()) +
+                       enc.PredictMaxFinishOutput());
+
+            uint64_t written = enc.Update(out.begin(), out.end(), data.begin(), data.end());
+            written += enc.Finish(out.begin() + written, out.end());
+
+            out.resize(written);
+            return out;
+        }
+    };
+
+    Helper ecbEnc;
+
+    {
+        std::vector<uint8_t> data = {};
+        std::vector<uint8_t> key = { 0xaa, 0xbb, 0xaa, 0xbb, 0xaa, 0xbb, 0xaa, 0xbb };
+
+        std::vector<uint8_t> expected = { 0xef, 0xe2, 0x4d, 0xe9, 0x9d, 0xe7, 0x9b, 0xbf };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        const char * str = "smoke and mirrors";
+        std::vector<uint8_t> data(str, str + strlen(str));
+        std::vector<uint8_t> key = { 0x0c, 0xfd, 0x01, 0xa3, 0x60, 0xd0, 0x15, 0xa6 };
+
+        std::vector<uint8_t> expected = { 0x84, 0x39, 0xcd, 0xe5, 0x1f, 0x3d,
+                                          0x2a, 0x11, 0x63, 0xc3, 0x56, 0x28,
+                                          0xf5, 0x89, 0xdb, 0xc4, 0xa6, 0xca,
+                                          0x52, 0xb3, 0xa8, 0xce, 0x64, 0x2d };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x51, 0x89, 0x9f, 0x0c, 0x32, 0x9b, 0x1d };
+        std::vector<uint8_t> key = { 0x28, 0x1c, 0xf3, 0x11, 0xce, 0xc6, 0xc2, 0x38 };
+
+        std::vector<uint8_t> expected = { 0x64, 0x32, 0x13, 0xe7, 0x31, 0x06, 0xc6, 0x6f };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x32, 0x00, 0x93, 0x61, 0xc6, 0x9a, 0x25, 0x25, 0x2e };
+        std::vector<uint8_t> key = { 0x28, 0x1c, 0xf3, 0x11, 0xce, 0xc6, 0xc2, 0x38 };
+
+        std::vector<uint8_t> expected = { 0xee, 0x5b, 0x16, 0x33, 0xad, 0x2d, 0x32, 0x42,
+                                          0xdc, 0x0d, 0x9f, 0x87, 0x55, 0x5b, 0xb1, 0x53 };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x4d, 0x0d, 0xfb, 0x59, 0xe6, 0xc4, 0xf2, 0xe7,
+                                      0xab, 0x46, 0x4f, 0x59, 0x48, 0x11, 0x1b, 0x4f };
+        std::vector<uint8_t> key = { 0x44, 0x0a, 0xb1, 0x6d, 0xe0, 0x67, 0x28, 0x9d };
+
+        std::vector<uint8_t> expected = { 0x55, 0xc1, 0x6f, 0xbb, 0xb0, 0xf3, 0xd3, 0xa6, 0xb7, 0xe6, 0x12, 0xb4,
+                                          0x49, 0x86, 0x64, 0x07, 0x82, 0xbb, 0x45, 0x46, 0x70, 0xae, 0x64, 0x5f };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x8a, 0xe3, 0x85, 0xe0, 0x59, 0xe7, 0xee, 0xce, 0xc0, 0xbf, 0x50, 0x53,
+                                      0x95, 0xbf, 0x4b, 0xdd, 0x3b, 0x02, 0x2f, 0xcb, 0xd0, 0xd3, 0x62, 0x60 };
+        std::vector<uint8_t> key = { 0xe4, 0x60, 0xb9, 0xfa, 0x4b, 0x79, 0x6a, 0xf3 };
+
+        std::vector<uint8_t> expected = { 0xf4, 0x46, 0x31, 0xc5, 0xe8, 0xff, 0xdc, 0xac, 0x6c, 0x0e, 0xe8, 0x0e,
+                                          0x9f, 0xc2, 0xeb, 0xdf, 0xca, 0xac, 0xc3, 0xc0, 0xea, 0xba, 0x6e, 0xc2,
+                                          0x33, 0x5d, 0x16, 0x39, 0x74, 0xd1, 0x1d, 0xe1 };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x96, 0x9f, 0x42, 0xd3, 0x47, 0x10, 0x4d, 0xb4, 0x89, 0x54,
+                                      0x5c, 0xad, 0x0a, 0xb9, 0xac, 0x4e, 0xbf, 0x00, 0x1a, 0x47,
+                                      0x3d, 0xd1, 0xe7, 0xb3, 0x70, 0xb7, 0x4e, 0xd9, 0x73, 0x7d,
+                                      0xb3, 0x24 };
+        std::vector<uint8_t> key = { 0xe9, 0xeb, 0x1f, 0xfa, 0x39, 0x95, 0xf0, 0xb9 };
+
+        std::vector<uint8_t> expected = { 0x53, 0x06, 0x73, 0x79, 0xb8, 0xd7, 0xbe, 0x5d, 0x6e, 0xa0,
+                                          0x1f, 0x03, 0x46, 0x07, 0xd6, 0x48, 0x65, 0x4f, 0x9a, 0x8f,
+                                          0x1a, 0xe4, 0xa7, 0x7f, 0x13, 0xc9, 0x06, 0x8c, 0x57, 0xbd,
+                                          0x79, 0x5e, 0x3d, 0x21, 0x02, 0x13, 0x5f, 0xae, 0xc9, 0x45 };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0xde, 0xbf, 0x28, 0x16, 0x0d, 0xfe, 0x64, 0xbf, 0xc6, 0xfd,
+                                      0x2d, 0x32, 0x45, 0xb0, 0xb7, 0x53, 0xde, 0x5a, 0x8e, 0x45,
+                                      0x87, 0xb3, 0x94, 0x0b, 0xdb, 0x9d, 0x23, 0x33, 0xd7, 0x8e,
+                                      0x63, 0x2d, 0x56 };
+        std::vector<uint8_t> key = { 0x3b, 0x4d, 0xdd, 0x0a, 0x28, 0xf5, 0x96, 0x36 };
+
+        std::vector<uint8_t> expected = { 0xc2, 0x88, 0xe5, 0x27, 0xd1, 0xb4, 0xa5, 0xf9, 0xb6, 0x02,
+                                          0x43, 0x3e, 0xae, 0x59, 0x43, 0xd4, 0xe5, 0x87, 0x20, 0xfe,
+                                          0xd0, 0x34, 0x28, 0x6a, 0xef, 0xb1, 0x9e, 0x5a, 0xdf, 0xfb,
+                                          0xf7, 0x94, 0xb4, 0x0c, 0xc2, 0x92, 0x4e, 0x73, 0xda, 0xca };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+
+    {
+        std::vector<uint8_t> data = { 0x7e, 0x2c, 0x68, 0x20, 0x22, 0xb1, 0xdd, 0x6d, 0x6e, 0x8b, 0x8b,
+                                      0x30, 0x99, 0xaf, 0x79, 0x2f, 0x6c, 0x95, 0x11, 0x8d, 0xd4, 0x2f,
+                                      0xcf, 0x1d, 0xe6, 0xa0, 0xc7, 0x73, 0x48, 0xb1, 0x65, 0xa9, 0xf6,
+                                      0xc5, 0x1c, 0x42, 0x2d, 0xdd, 0xcf, 0xf5, 0xd4, 0xee, 0xa5, 0xa7,
+                                      0x69, 0xf9, 0x27, 0x93, 0xce };
+        std::vector<uint8_t> key = { 0x3c, 0xd0, 0xab, 0xd3, 0xb4, 0xc3, 0xac, 0x53 };
+
+        std::vector<uint8_t> expected = { 0xf7, 0x44, 0x18, 0x9b, 0x9d, 0x8d, 0xe1, 0x14, 0xcd, 0x0a, 0xdb, 0xbd,
+                                          0x5b, 0xd1, 0x42, 0x6e, 0x17, 0x73, 0x60, 0x9e, 0x14, 0xad, 0xd2, 0x4c,
+                                          0x33, 0x30, 0xdd, 0xb9, 0xf3, 0x46, 0xd0, 0x8d, 0xa6, 0x37, 0x49, 0xd7,
+                                          0x90, 0x23, 0x05, 0xcc, 0x56, 0xde, 0x1f, 0xde, 0x39, 0x6c, 0x04, 0x97,
+                                          0x1d, 0xaf, 0xb5, 0xff, 0xab, 0x47, 0xc8, 0x51 };
+
+        ASSERT_EQ(expected, ecbEnc(data, key));
+    }
+}
+
+TEST(EcbModeTests, EncryptManyUpdatesTest)
+{
+    struct Helper
+    {
+        Helper(const std::vector<uint8_t> & key)
+            : Key_(key.begin(), key.end())
+            , Enc_(Key_)
+            , Written_(0)
+        { }
+
+        void Update(const std::vector<uint8_t> & data)
+        {
+            Out_.resize(Out_.size() + Enc_.PredictMaxUpdateOutput(data.size()));
+
+            Written_ += Enc_.Update(Out_.begin() + Written_, Out_.end(),
+                                    data.begin(), data.end());
+        }
+
+        std::vector<uint8_t> Finish()
+        {
+            Out_.resize(Out_.size() + Enc_.PredictMaxFinishOutput());
+
+            Written_ += Enc_.Finish(Out_.begin() + Written_, Out_.end());
+            Out_.resize(Written_);
+
+            return Out_;
+        }
+
+        Des::DesCrypt::Key Key_;
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor Enc_;
+
+        std::vector<uint8_t> Out_;
+        uint64_t Written_;
+    };
+
+    {
+        std::vector<uint8_t> key = { 0xab, 0x39, 0x20, 0xea, 0xaa, 0x95, 0x1c, 0x90 };
+
+        std::vector<uint8_t> data1 = { 0x97, 0x65, 0xe2, 0xb1, 0xae, 0x3e, 0x55, 0xff, 0x1d };
+        std::vector<uint8_t> data2 = { 0xac, 0x8a, 0xa6, 0xac, 0xa5, 0x9a, 0xf9, 0xb6 };
+        std::vector<uint8_t> data3 = { 0x3c, 0xba, 0x95, 0x5e, 0x78, 0x29, 0x22, 0x7c, 0x12, 0x7e, 0x4c };
+
+        std::vector<uint8_t> expected = { 0xf4, 0xde, 0x9a, 0xe4, 0x78, 0x8c, 0xf2, 0xe6, 0x75, 0x34, 0xe7,
+                                          0x9f, 0xe8, 0x16, 0x09, 0x12, 0x55, 0x75, 0x5b, 0xe4, 0x21, 0x65,
+                                          0x98, 0x0e, 0xc6, 0x7a, 0x62, 0xf6, 0x88, 0xcd, 0x3e, 0x83 };
+
+        Helper ecbEnc(key);
+
+        ecbEnc.Update(data1);
+        ecbEnc.Update(data2);
+        ecbEnc.Update(data3);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+
+    {
+        std::vector<uint8_t> key = { 0xd5, 0xc1, 0x3a, 0xcc, 0x6f, 0x86, 0x1d, 0x4b };
+
+        std::vector<uint8_t> data1 = { 0x43, 0x73, 0x1b, 0xde, 0xbd, 0xfe, 0x16, 0x58 };
+        std::vector<uint8_t> data2 = { 0x8c, 0x16, 0x13, 0x53, 0x22, 0x66, 0xb4, 0xf2 };
+        std::vector<uint8_t> data3 = { 0x25, 0xcf, 0xcd, 0xab, 0x7d, 0x29, 0x9a, 0xd7 };
+
+        std::vector<uint8_t> expected = { 0x5f, 0x18, 0x61, 0x15, 0x72, 0x75, 0x73, 0xb3, 0x44,
+                                          0xa5, 0xf0, 0x46, 0xa9, 0x4b, 0x7e, 0x5e, 0x5b, 0x88,
+                                          0x46, 0x07, 0x5e, 0x33, 0x16, 0x01, 0x69, 0x13, 0x76,
+                                          0x8b, 0x7f, 0xbc, 0xf2, 0x75 };
+
+        Helper ecbEnc(key);
+
+        ecbEnc.Update(data1);
+        ecbEnc.Update(data2);
+        ecbEnc.Update(data3);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+
+    {
+        std::vector<uint8_t> key = { 0xc0, 0x98, 0x56, 0xb3, 0x27, 0xc9, 0x78, 0x89 };
+
+        std::vector<uint8_t> data1 = { 0xb7 };
+        std::vector<uint8_t> data2 = { 0xb3 };
+        std::vector<uint8_t> data3 = { 0x95, 0x56, 0xc0, 0x9f, 0x74, 0xd0, 0x49, 0xb5 };
+        std::vector<uint8_t> data4 = { 0x15 };
+
+        std::vector<uint8_t> expected = { 0xf9, 0x79, 0x6d, 0x46, 0xb6, 0x4a, 0xa8, 0xaa, 0x82,
+                                          0xb9, 0xca, 0x65, 0xe9, 0x3c, 0xa8, 0xdc };
+
+        Helper ecbEnc(key);
+
+        ecbEnc.Update(data1);
+        ecbEnc.Update(data2);
+        ecbEnc.Update(data3);
+        ecbEnc.Update(data4);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+
+    {
+        std::vector<uint8_t> key = { 0xcb, 0x22, 0x90, 0x27, 0x87, 0x42, 0xd1, 0x58 };
+
+        std::vector<uint8_t> data1 = { 0xca, 0x40, 0xeb, 0x08, 0x75, 0x62, 0x41 };
+        std::vector<uint8_t> data2 = { 0x16, 0xa4, 0x12, 0x21, 0x3d, 0x5a, 0xf2, 0xb4, 0xa7, 0xb5, 0xa7 };
+        std::vector<uint8_t> data3 = { 0x59, 0x51, 0xd0, 0x41, 0x21, 0xf0, 0x2b, 0x76,
+                                       0xd8, 0xe4, 0x60, 0xb5, 0xab, 0xd8, 0x25, 0x29 };
+        std::vector<uint8_t> data4 = { 0x94, 0x9f, 0xed };
+        std::vector<uint8_t> data5 = { 0x1a, 0xa1, 0x57, 0x35, 0x2c };
+
+        std::vector<uint8_t> expected = { 0xfb, 0x9d, 0x21, 0x86, 0x9b, 0xf1, 0x79, 0xeb, 0x6c,
+                                          0xcf, 0xcc, 0xe7, 0x55, 0x48, 0x05, 0x42, 0x37, 0x23,
+                                          0xcc, 0xda, 0x82, 0x8f, 0xe7, 0x5a, 0x08, 0x85, 0x00,
+                                          0x0b, 0x38, 0x5f, 0x54, 0x53, 0xf9, 0x40, 0x59, 0xc7,
+                                          0xf3, 0x06, 0x10, 0x10, 0xed, 0xfc, 0x76, 0xff, 0xe6,
+                                          0x55, 0xb0, 0xe1 };
+
+        Helper ecbEnc(key);
+
+        ecbEnc.Update(data1);
+        ecbEnc.Update(data2);
+        ecbEnc.Update(data3);
+        ecbEnc.Update(data4);
+        ecbEnc.Update(data5);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+}
+
+TEST(EcbModeTests, EncryptLongInputTest)
+{
+    struct Helper
+    {
+        Helper(const std::vector<uint8_t> & key)
+            : Key_(key.begin(), key.end())
+            , Enc_(Key_)
+            , Written_(0)
+        { }
+
+        void Update(const std::vector<uint8_t> & data)
+        {
+            Out_.resize(Out_.size() + Enc_.PredictMaxUpdateOutput(data.size()));
+
+            Written_ += Enc_.Update(Out_.begin() + Written_, Out_.end(),
+                                    data.begin(), data.end());
+        }
+
+        void Update(std::vector<uint8_t>::const_iterator begin, std::vector<uint8_t>::const_iterator end)
+        {
+            Out_.resize(Out_.size() + Enc_.PredictMaxUpdateOutput(std::distance(begin, end)));
+            Written_ += Enc_.Update(Out_.begin() + Written_, Out_.end(), begin, end);
+        }
+
+        std::vector<uint8_t> Finish()
+        {
+            Out_.resize(Out_.size() + Enc_.PredictMaxFinishOutput());
+
+            Written_ += Enc_.Finish(Out_.begin() + Written_, Out_.end());
+            Out_.resize(Written_);
+
+            return Out_;
+        }
+
+        Des::DesCrypt::Key Key_;
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor Enc_;
+
+        std::vector<uint8_t> Out_;
+        uint64_t Written_;
+    };
+
+    {
+        std::vector<uint8_t> key = { 0x27, 0x07, 0x7c, 0xc9, 0xd2, 0xbe, 0x76, 0x6c };
+        std::vector<uint8_t> data(2048, 0xab);
+
+        std::vector<uint8_t> expected;
+
+        {
+            std::vector<uint8_t> block = { 0x90, 0xf0, 0x72, 0xae, 0xcc, 0x98, 0x93, 0x8d };
+
+            for (int i = 0; i < 256; ++i)
+            {
+                expected.insert(expected.end(), block.begin(), block.end());
+            }
+
+            std::vector<uint8_t> lastBlock = { 0xce, 0x7c, 0x12, 0x8e, 0x8c, 0xc0, 0x88, 0x02 };
+            expected.insert(expected.end(), lastBlock.begin(), lastBlock.end());
+        }
+
+        Helper ecbEnc(key);
+        ecbEnc.Update(data);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+
+    {
+        std::vector<uint8_t> key = { 0xcc, 0xc5, 0x08, 0x98, 0xe9, 0x8c, 0xeb, 0x23 };
+        std::vector<uint8_t> data(4095, 0x7a);
+
+        std::vector<uint8_t> expected;
+        {
+            std::vector<uint8_t> block = { 0xb7, 0x9f, 0x07, 0x2c, 0xe9, 0x54, 0x83, 0xc5 };
+
+            for (int i = 0; i < 2048; ++i)
+            {
+                expected.insert(expected.end(), block.begin(), block.end());
+            }
+
+            std::vector<uint8_t> lastBlock = { 0x14, 0x59, 0x29, 0x72, 0x45, 0xb3, 0x03, 0xb3 };
+            expected.insert(expected.end(), lastBlock.begin(), lastBlock.end());
+        }
+
+        Helper ecbEnc(key);
+
+        ecbEnc.Update(data.begin(), data.begin() + 2340);
+        ecbEnc.Update(data.begin(), data.begin() + 1171);
+        ecbEnc.Update(data.begin(), data.begin() + 2925);
+        ecbEnc.Update(data.begin(), data.begin() + 1);
+        ecbEnc.Update(data.begin(), data.begin() + 4095);
+        ecbEnc.Update(data.begin(), data.begin() + 586);
+        ecbEnc.Update(data.begin(), data.begin() + 3510);
+        ecbEnc.Update(data.begin(), data.begin() + 1756);
+
+        ASSERT_EQ(expected, ecbEnc.Finish());
+    }
+}
+
+TEST(EcbModeTests, EncryptInsufficientBufferTest)
+{
+    std::vector<uint8_t> key = { 0xcc, 0xc5, 0x08, 0x98, 0xe9, 0x8c, 0xeb, 0x23 };
+    Des::DesCrypt::Key desKey(key.begin(), key.end());
+
+    {
+        std::vector<uint8_t> data(8, 0xaa);
+        std::vector<uint8_t> out;
+
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+        ASSERT_THROW(enc.Update(out.begin(), out.end(), data.begin(), data.end()),
+                     Chaos::Service::ChaosException);
+    }
+
+    {
+        std::vector<uint8_t> data(8, 0xaa);
+        std::vector<uint8_t> out(7, 0);
+
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+        ASSERT_THROW(enc.Update(out.begin(), out.end(), data.begin(), data.end()),
+                     Chaos::Service::ChaosException);
+    }
+
+    {
+        std::vector<uint8_t> data1(7, 0xaa);
+        std::vector<uint8_t> data2(2, 0xbb);
+
+        std::vector<uint8_t> out1(7, 0);
+        std::vector<uint8_t> out2(2, 0);
+
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+        enc.Update(out1.begin(), out1.end(), data1.begin(), data1.end());
+
+        ASSERT_THROW(enc.Update(out2.begin(), out2.end(), data2.begin(), data2.end()),
+                     Chaos::Service::ChaosException);
+    }
+
+    {
+        std::vector<uint8_t> data(8, 0xaa);
+        std::vector<uint8_t> out(8, 0);
+
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+        uint64_t written = enc.Update(out.begin(), out.end(), data.begin(), data.end());
+
+        ASSERT_THROW(written += enc.Finish(out.begin() + written, out.end()),
+                     Chaos::Service::ChaosException);
+    }
+
+    {
+        std::vector<uint8_t> data(15, 0xaa);
+        std::vector<uint8_t> out(15, 0);
+
+        EcbMode<Des::DesCrypt, PadderPkcs7>::Encryptor enc(desKey);
+
+        uint64_t written = enc.Update(out.begin(), out.end(), data.begin(), data.end());
+
+        ASSERT_THROW(written += enc.Finish(out.begin() + written, out.end()),
+                     Chaos::Service::ChaosException);
+    }
+}