diff --git a/crypto/aes_ctr.go b/crypto/aes_ctr.go
new file mode 100644
index 0000000..1057c2c
--- /dev/null
+++ b/crypto/aes_ctr.go
@@ -0,0 +1,67 @@
+package coscrypto
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"io"
+)
+
+type aesCtr struct {
+	encrypter cipher.Stream
+	decrypter cipher.Stream
+}
+
+func newAesCtr(cd CipherData) (Cipher, error) {
+	block, err := aes.NewCipher(cd.Key)
+	if err != nil {
+		return nil, err
+	}
+	encrypter := cipher.NewCTR(block, cd.IV)
+	decrypter := cipher.NewCTR(block, cd.IV)
+	return &aesCtr{encrypter, decrypter}, nil
+}
+
+func (c *aesCtr) Encrypt(src io.Reader) io.Reader {
+	reader := &ctrEncryptReader{
+		encrypter: c.encrypter,
+		src:       src,
+	}
+	return reader
+}
+
+type ctrEncryptReader struct {
+	encrypter cipher.Stream
+	src       io.Reader
+}
+
+func (reader *ctrEncryptReader) Read(data []byte) (int, error) {
+	plainText := make([]byte, len(data), len(data))
+	n, err := reader.src.Read(plainText)
+	if n > 0 {
+		plainText = plainText[0:n]
+		reader.encrypter.XORKeyStream(data, plainText)
+	}
+	return n, err
+}
+
+func (c *aesCtr) Decrypt(src io.Reader) io.Reader {
+	return &ctrDecryptReader{
+		decrypter: c.decrypter,
+		src:       src,
+	}
+}
+
+type ctrDecryptReader struct {
+	decrypter cipher.Stream
+	src       io.Reader
+}
+
+func (reader *ctrDecryptReader) Read(data []byte) (int, error) {
+	cryptoText := make([]byte, len(data), len(data))
+	n, err := reader.src.Read(cryptoText)
+	if n > 0 {
+		cryptoText = cryptoText[0:n]
+		reader.decrypter.XORKeyStream(data, cryptoText)
+	}
+	return n, err
+}
diff --git a/crypto/aes_ctr_cipher.go b/crypto/aes_ctr_cipher.go
new file mode 100644
index 0000000..c140cd7
--- /dev/null
+++ b/crypto/aes_ctr_cipher.go
@@ -0,0 +1,138 @@
+package coscrypto
+
+import (
+	"io"
+)
+
+const (
+	aesKeySize = 32
+	ivSize     = 16
+)
+
+type aesCtrCipherBuilder struct {
+	MasterCipher MasterCipher
+}
+
+type aesCtrCipher struct {
+	CipherData CipherData
+	Cipher     Cipher
+}
+
+func CreateAesCtrBuilder(cipher MasterCipher) ContentCipherBuilder {
+	return aesCtrCipherBuilder{MasterCipher: cipher}
+}
+
+func (builder aesCtrCipherBuilder) createCipherData() (CipherData, error) {
+	var cd CipherData
+	var err error
+	err = cd.RandomKeyIv(aesKeySize, ivSize)
+	if err != nil {
+		return cd, err
+	}
+
+	cd.WrapAlgorithm = builder.MasterCipher.GetWrapAlgorithm()
+	cd.CEKAlgorithm = AesCtrAlgorithm
+	cd.MatDesc = builder.MasterCipher.GetMatDesc()
+
+	// EncryptedKey
+	cd.EncryptedKey, err = builder.MasterCipher.Encrypt(cd.Key)
+	if err != nil {
+		return cd, err
+	}
+
+	// EncryptedIV
+	cd.EncryptedIV, err = builder.MasterCipher.Encrypt(cd.IV)
+	if err != nil {
+		return cd, err
+	}
+
+	return cd, nil
+}
+
+func (builder aesCtrCipherBuilder) contentCipherCD(cd CipherData) (ContentCipher, error) {
+	cipher, err := newAesCtr(cd)
+	if err != nil {
+		return nil, err
+	}
+
+	return &aesCtrCipher{
+		CipherData: cd,
+		Cipher:     cipher,
+	}, nil
+}
+
+func (builder aesCtrCipherBuilder) ContentCipher() (ContentCipher, error) {
+	cd, err := builder.createCipherData()
+	if err != nil {
+		return nil, err
+	}
+	return builder.contentCipherCD(cd)
+}
+
+func (builder aesCtrCipherBuilder) ContentCipherEnv(envelope Envelope) (ContentCipher, error) {
+	var cd CipherData
+	cd.EncryptedKey = make([]byte, len(envelope.CipherKey))
+	copy(cd.EncryptedKey, []byte(envelope.CipherKey))
+
+	plainKey, err := builder.MasterCipher.Decrypt([]byte(envelope.CipherKey))
+	if err != nil {
+		return nil, err
+	}
+	cd.Key = make([]byte, len(plainKey))
+	copy(cd.Key, plainKey)
+
+	cd.EncryptedIV = make([]byte, len(envelope.IV))
+	copy(cd.EncryptedIV, []byte(envelope.IV))
+
+	plainIV, err := builder.MasterCipher.Decrypt([]byte(envelope.IV))
+	if err != nil {
+		return nil, err
+	}
+
+	cd.IV = make([]byte, len(plainIV))
+	copy(cd.IV, plainIV)
+
+	cd.MatDesc = envelope.MatDesc
+	cd.WrapAlgorithm = envelope.WrapAlg
+	cd.CEKAlgorithm = envelope.CEKAlg
+
+	return builder.contentCipherCD(cd)
+}
+
+func (builder aesCtrCipherBuilder) GetMatDesc() string {
+	return builder.MasterCipher.GetMatDesc()
+}
+
+func (cc *aesCtrCipher) EncryptContent(src io.Reader) (io.ReadCloser, error) {
+	reader := cc.Cipher.Encrypt(src)
+	return &CryptoEncrypter{Body: src, Encrypter: reader}, nil
+}
+
+func (cc *aesCtrCipher) DecryptContent(src io.Reader) (io.ReadCloser, error) {
+	reader := cc.Cipher.Decrypt(src)
+	return &CryptoDecrypter{Body: src, Decrypter: reader}, nil
+}
+
+func (cc *aesCtrCipher) GetCipherData() *CipherData {
+	return &(cc.CipherData)
+}
+
+func (cc *aesCtrCipher) GetEncryptedLen(plainTextLen int64) int64 {
+	return plainTextLen
+}
+
+func (cc *aesCtrCipher) GetAlignLen() int {
+	return len(cc.CipherData.IV)
+}
+
+func (cc *aesCtrCipher) Clone(cd CipherData) (ContentCipher, error) {
+	cipher, err := newAesCtr(cd)
+	if err != nil {
+		return nil, err
+	}
+
+	return &aesCtrCipher{
+		CipherData: cd,
+		Cipher:     cipher,
+	}, nil
+}
diff --git a/crypto/aes_ctr_cipher_test.go b/crypto/aes_ctr_cipher_test.go
new file mode 100644
index 0000000..f8ebd07
--- /dev/null
+++ b/crypto/aes_ctr_cipher_test.go
@@ -0,0 +1,107 @@
+package coscrypto_test
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"github.com/stretchr/testify/assert"
+	"github.com/tencentyun/cos-go-sdk-v5/crypto"
+	"io/ioutil"
+	math_rand "math/rand"
+)
+
+type EmptyMasterCipher struct{}
+
+func (mc EmptyMasterCipher) Encrypt(b []byte) ([]byte, error) {
+	return b, nil
+}
+func (mc EmptyMasterCipher) Decrypt(b []byte) ([]byte, error) {
+	return b, nil
+}
+func (mc EmptyMasterCipher) GetWrapAlgorithm() string {
+	return "Test/EmptyWrapAlgo"
+}
+func (mc EmptyMasterCipher) GetMatDesc() string {
+	return "Empty Desc"
+}
+
+func (s *CosTestSuite) TestCryptoObjectService_EncryptAndDecrypt() {
+	var masterCipher EmptyMasterCipher
+	builder := coscrypto.CreateAesCtrBuilder(masterCipher)
+
+	contentCipher, err := builder.ContentCipher()
+	assert.Nil(s.T(), err, "CryptoObject.CreateAesCtrBuilder Failed")
+
+	dataSize := math_rand.Int63n(1024 * 1024 * 32)
+	originData := make([]byte, dataSize)
+	rand.Read(originData)
+	// 加密
+	r1 := bytes.NewReader(originData)
+	reader1, err := contentCipher.EncryptContent(r1)
+	assert.Nil(s.T(), err, "CryptoObject.contentCipher.Encrypt Failed")
+	encryptedData, err := ioutil.ReadAll(reader1)
+	assert.Nil(s.T(), err, "CryptoObject.Read Failed")
+
+	// 解密
+	r2 := bytes.NewReader(encryptedData)
+	reader2, err := contentCipher.DecryptContent(r2)
+	decryptedData, err := ioutil.ReadAll(reader2)
+	assert.Nil(s.T(), err, "CryptoObject.Read Failed")
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+}
+
+func (s *CosTestSuite) TestCryptoObjectService_Encrypt() {
+	var masterCipher EmptyMasterCipher
+	builder := coscrypto.CreateAesCtrBuilder(masterCipher)
+
+	contentCipher, err := builder.ContentCipher()
+	assert.Nil(s.T(), err, "CryptoObject.CreateAesCtrBuilder Failed")
+
+	dataSize := math_rand.Int63n(1024 * 1024 * 32)
+	originData := make([]byte, dataSize)
+	rand.Read(originData)
+
+	// 加密
+	r := bytes.NewReader(originData)
+	reader, err := contentCipher.EncryptContent(r)
+	assert.Nil(s.T(), err, "CryptoObject.contentCipher.Encrypt Failed")
+	encryptedData, err := ioutil.ReadAll(reader)
+	assert.Nil(s.T(), err, "CryptoObject.Read Failed")
+
+	// 直接解密
+	cd := contentCipher.GetCipherData()
+	block, err := aes.NewCipher(cd.Key)
+	assert.Nil(s.T(), err, "CryptoObject.NewCipher Failed")
+	decrypter := cipher.NewCTR(block, cd.IV)
+	decryptedData := make([]byte, len(originData))
+	decrypter.XORKeyStream(decryptedData, encryptedData)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+}
+
+func (s *CosTestSuite) TestCryptoObjectService_Decrypt() {
+	var masterCipher EmptyMasterCipher
+	builder := coscrypto.CreateAesCtrBuilder(masterCipher)
+
+	contentCipher, err := builder.ContentCipher()
+	assert.Nil(s.T(), err, "CryptoObject.CreateAesCtrBuilder Failed")
+	dataSize := math_rand.Int63n(1024 * 1024 * 32)
+	originData := make([]byte, dataSize)
+	rand.Read(originData)
+
+	// 直接加密
+	cd := contentCipher.GetCipherData()
+	block, err := aes.NewCipher(cd.Key)
+	assert.Nil(s.T(), err, "CryptoObject.NewCipher Failed")
+	encrypter := cipher.NewCTR(block, cd.IV)
+	encryptedData := make([]byte, len(originData))
+	encrypter.XORKeyStream(encryptedData, originData)
+
+	// 解密
+	r := bytes.NewReader(encryptedData)
+	reader, err := contentCipher.DecryptContent(r)
+	assert.Nil(s.T(), err, "CryptoObject.contentCipher.Encrypt Failed")
+	decryptedData, err := ioutil.ReadAll(reader)
+	assert.Nil(s.T(), err, "CryptoObject.Read Failed")
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+}
diff --git a/crypto/cipher.go b/crypto/cipher.go
new file mode 100644
index 0000000..445f3e1
--- /dev/null
+++ b/crypto/cipher.go
@@ -0,0 +1,69 @@
+package coscrypto
+
+import (
+	"io"
+)
+
+// Cipher is interface for encryption or decryption of an object
+type Cipher interface {
+	Encrypter
+	Decrypter
+}
+
+// Encrypter is interface with only encrypt method
+type Encrypter interface {
+	Encrypt(io.Reader) io.Reader
+}
+
+// Decrypter is interface with only decrypt method
+type Decrypter interface {
+	Decrypt(io.Reader) io.Reader
+}
+
+// CryptoEncrypter provides close method for Encrypter
+type CryptoEncrypter struct {
+	Body      io.Reader
+	Encrypter io.Reader
+	isClosed  bool
+}
+
+// Close lets the CryptoEncrypter satisfy io.ReadCloser interface
+func (rc *CryptoEncrypter) Close() error {
+	rc.isClosed = true
+	if closer, ok := rc.Body.(io.ReadCloser); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
+// Read lets the CryptoEncrypter satisfy io.ReadCloser interface
+func (rc *CryptoEncrypter) Read(b []byte) (int, error) {
+	if rc.isClosed {
+		return 0, io.EOF
+	}
+	return rc.Encrypter.Read(b)
+}
+
+// CryptoDecrypter provides close method for Decrypter
+type CryptoDecrypter struct {
+	Body      io.Reader
+	Decrypter io.Reader
+	isClosed  bool
+}
+
+// Close lets the CryptoDecrypter satisfy io.ReadCloser interface
+func (rc *CryptoDecrypter) Close() error {
+	rc.isClosed = true
+	if closer, ok := rc.Body.(io.ReadCloser); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
+// Read lets the CryptoDecrypter satisfy io.ReadCloser interface
+func (rc *CryptoDecrypter) Read(b []byte) (int, error) {
+	if rc.isClosed {
+		return 0, io.EOF
+	}
+	return rc.Decrypter.Read(b)
+}
diff --git a/crypto/crypto_object.go b/crypto/crypto_object.go
new file mode 100644
index 0000000..903bf6a
--- /dev/null
+++ b/crypto/crypto_object.go
@@ -0,0 +1,228 @@
+package coscrypto
+
+import (
+	"context"
+	"fmt"
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+)
+
+type CryptoObjectService struct {
+	*cos.ObjectService
+	cryptoClient *CryptoClient
+}
+
+type CryptoClient struct {
+	*cos.Client
+	Object               *CryptoObjectService
+	ContentCipherBuilder ContentCipherBuilder
+
+	userAgent string
+}
+
+func NewCryptoClient(client *cos.Client, masterCipher MasterCipher) *CryptoClient {
+	cc := &CryptoClient{
+		Client: client,
+		Object: &CryptoObjectService{
+			client.Object,
+			nil,
+		},
+		ContentCipherBuilder: CreateAesCtrBuilder(masterCipher),
+	}
+	cc.userAgent = cc.Client.UserAgent + "/" + EncryptionUaSuffix
+	cc.Object.cryptoClient = cc
+
+	return cc
+}
+
+func (s *CryptoObjectService) Put(ctx context.Context, name string, r io.Reader, opt *cos.ObjectPutOptions) (*cos.Response, error) {
+	cc, err := s.cryptoClient.ContentCipherBuilder.ContentCipher()
+	if err != nil {
+		return nil, err
+	}
+	reader, err := cc.EncryptContent(r)
+	if err != nil {
+		return nil, err
+	}
+	opt = cos.CloneObjectPutOptions(opt)
+	totalBytes, err := cos.GetReaderLen(r)
+	if err != nil && opt != nil && opt.Listener != nil && opt.ContentLength == 0 {
+		return nil, err
+	}
+	if err == nil {
+		if opt != nil && opt.ContentLength == 0 {
+			// 如果未设置Listener, 非bytes.Buffer/bytes.Reader/strings.Reader由用户指定Contength
+			if opt.Listener != nil || cos.IsLenReader(r) {
+				opt.ContentLength = totalBytes
+			}
+		}
+	}
+	if opt.XOptionHeader == nil {
+		opt.XOptionHeader = &http.Header{}
+	}
+	if opt.ContentMD5 != "" {
+		opt.XOptionHeader.Add(COSClientSideEncryptionUnencryptedContentMD5, opt.ContentMD5)
+		opt.ContentMD5 = ""
+	}
+	if opt.ContentLength != 0 {
+		opt.XOptionHeader.Add(COSClientSideEncryptionUnencryptedContentLength, strconv.FormatInt(opt.ContentLength, 10))
+		opt.ContentLength = cc.GetEncryptedLen(opt.ContentLength)
+	}
+	addCryptoHeaders(opt.XOptionHeader, cc.GetCipherData())
+
+	return s.ObjectService.Put(ctx, name, reader, opt)
+}
+
+func (s *CryptoObjectService) PutFromFile(ctx context.Context, name, filePath string, opt *cos.ObjectPutOptions) (resp *cos.Response, err error) {
+	nr := 0
+	for nr < 3 {
+		fd, e := os.Open(filePath)
+		if e != nil {
+			err = e
+			return
+		}
+		resp, err = s.Put(ctx, name, fd, opt)
+		if err != nil {
+			nr++
+			fd.Close()
+			continue
+		}
+		fd.Close()
+		break
+	}
+	return
+}
+
+func (s *CryptoObjectService) Get(ctx context.Context, name string, opt *cos.ObjectGetOptions) (*cos.Response, error) {
+	meta, err := s.ObjectService.Head(ctx, name, nil)
+	if err != nil {
+		return meta, err
+	}
+	_isEncrypted := isEncrypted(&meta.Header)
+	if !_isEncrypted {
+		return s.ObjectService.Get(ctx, name, opt)
+	}
+
+	envelope := getEnvelopeFromHeader(&meta.Header)
+	if !envelope.IsValid() {
+		return nil, fmt.Errorf("get envelope from header failed, object:%v", name)
+	}
+	encryptMatDesc := s.cryptoClient.ContentCipherBuilder.GetMatDesc()
+	if envelope.MatDesc != encryptMatDesc {
+		return nil, fmt.Errorf("provided master cipher error, want:%v, return:%v, object:%v", encryptMatDesc, envelope.MatDesc, name)
+	}
+
+	cc, err := s.cryptoClient.ContentCipherBuilder.ContentCipherEnv(envelope)
+	if err != nil {
+		return nil, fmt.Errorf("get content cipher from envelope failed: %v, object:%v", err, name)
+	}
+
+	optRange, err := cos.GetRangeOptions(opt)
+	if err != nil {
+		return nil, err
+	}
+	discardAlignLen := int64(0)
+	// Range请求
+	if optRange != nil && optRange.HasStart {
+		// 加密block对齐
+		adjustStart := adjustRangeStart(optRange.Start, int64(cc.GetAlignLen()))
+		discardAlignLen = optRange.Start - adjustStart
+		if discardAlignLen > 0 {
+			optRange.Start = adjustStart
+			opt = cos.CloneObjectGetOptions(opt)
+			opt.Range = cos.FormatRangeOptions(optRange)
+		}
+
+		cd := cc.GetCipherData().Clone()
+		cd.SeekIV(uint64(adjustStart))
+		cc, err = cc.Clone(cd)
+		if err != nil {
+			return nil, fmt.Errorf("ContentCipher Clone failed:%v, bject:%v", err, name)
+		}
+	}
+	resp, err := s.ObjectService.Get(ctx, name, opt)
+	if err != nil {
+		return resp, err
+	}
+	resp.Body, err = cc.DecryptContent(resp.Body)
+	if err != nil {
+		return resp, err
+	}
+	// 抛弃多读取的数据
+	if discardAlignLen > 0 {
+		resp.Body = &cos.DiscardReadCloser{
+			RC:      resp.Body,
+			Discard: int(discardAlignLen),
+		}
+	}
+	return resp, err
+}
+
+func (s *CryptoObjectService) GetToFile(ctx context.Context, name, localpath string, opt *cos.ObjectGetOptions) (*cos.Response, error) {
+	resp, err := s.Get(ctx, name, opt)
+	if err != nil {
+		return resp, err
+	}
+	defer resp.Body.Close()
+
+	// If file exist, overwrite it
+	fd, err := os.OpenFile(localpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0660)
+	if err != nil {
+		return resp, err
+	}
+
+	_, err = io.Copy(fd, resp.Body)
+	fd.Close()
+	if err != nil {
+		return resp, err
+	}
+
+	return resp, nil
+}
+
+func (s *CryptoObjectService) MultiUpload(ctx context.Context, name string, filepath string, opt *cos.MultiUploadOptions) (*cos.CompleteMultipartUploadResult, *cos.Response, error) {
+	return s.Upload(ctx, name, filepath, opt)
+}
+
+func (s *CryptoObjectService) Upload(ctx context.Context, name string, filepath string, opt *cos.MultiUploadOptions) (*cos.CompleteMultipartUploadResult, *cos.Response, error) {
+	return nil, nil, fmt.Errorf("CryptoObjectService doesn't support Upload Now")
+}
+
+func (s *CryptoObjectService) Download(ctx context.Context, name string, filepath string, opt *cos.MultiDownloadOptions) (*cos.Response, error) {
+	return nil, fmt.Errorf("CryptoObjectService doesn't support Download Now")
+}
+
+func adjustRangeStart(start int64, alignLen int64) int64 {
+	return (start / alignLen) * alignLen
+}
+
+func addCryptoHeaders(header *http.Header, cd *CipherData) {
+	if cd.MatDesc != "" {
+		header.Add(COSClientSideEncryptionMatDesc, cd.MatDesc)
+	}
+	header.Add(COSClientSideEncryptionKey, string(cd.EncryptedKey))
+	header.Add(COSClientSideEncryptionStart, string(cd.EncryptedIV))
+	header.Add(COSClientSideEncryptionWrapAlg, cd.WrapAlgorithm)
+	header.Add(COSClientSideEncryptionCekAlg, cd.CEKAlgorithm)
+}
+
+func getEnvelopeFromHeader(header *http.Header) Envelope {
+	var envelope Envelope
+	envelope.CipherKey = header.Get(COSClientSideEncryptionKey)
+	envelope.IV = header.Get(COSClientSideEncryptionStart)
+	envelope.MatDesc = header.Get(COSClientSideEncryptionMatDesc)
+	envelope.WrapAlg = header.Get(COSClientSideEncryptionWrapAlg)
+	envelope.CEKAlg = header.Get(COSClientSideEncryptionCekAlg)
+	return envelope
+}
+
+func isEncrypted(header *http.Header) bool {
+	encryptedKey := header.Get(COSClientSideEncryptionKey)
+	if len(encryptedKey) > 0 {
+		return true
+	}
+	return false
+}
diff --git a/crypto/crypto_object_part.go b/crypto/crypto_object_part.go
new file mode 100644
index 0000000..15561b4
--- /dev/null
+++ b/crypto/crypto_object_part.go
@@ -0,0 +1,76 @@
+package coscrypto
+
+import (
+	"context"
+	"fmt"
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"io"
+	"net/http"
+	"strconv"
+)
+
+type CryptoContext struct {
+	DataSize      int64
+	PartSize      int64
+	ContentCipher ContentCipher
+}
+
+func partSizeIsValid(partSize int64, alignLen int64) bool {
+	if partSize%alignLen == 0 {
+		return true
+	}
+	return false
+}
+
+func (s *CryptoObjectService) InitiateMultipartUpload(ctx context.Context, name string, opt *cos.InitiateMultipartUploadOptions, cryptoCtx *CryptoContext) (*cos.InitiateMultipartUploadResult, *cos.Response, error) {
+	contentCipher, err := s.cryptoClient.ContentCipherBuilder.ContentCipher()
+	if err != nil {
+		return nil, nil, err
+	}
+	if !partSizeIsValid(cryptoCtx.PartSize, int64(contentCipher.GetAlignLen())) {
+		return nil, nil, fmt.Errorf("PartSize is invalid, it should be %v aligned", contentCipher.GetAlignLen())
+	}
+	// 添加自定义头部
+	cryptoCtx.ContentCipher = contentCipher
+	opt = cos.CloneInitiateMultipartUploadOptions(opt)
+	if opt.XOptionHeader == nil {
+		opt.XOptionHeader = &http.Header{}
+	}
+	if opt.ContentMD5 != "" {
+		opt.XOptionHeader.Add(COSClientSideEncryptionUnencryptedContentMD5, opt.ContentMD5)
+		opt.ContentMD5 = ""
+	}
+	opt.XOptionHeader.Add(COSClientSideEncryptionUnencryptedContentLength, strconv.FormatInt(cryptoCtx.DataSize, 10))
+	addCryptoHeaders(opt.XOptionHeader, contentCipher.GetCipherData())
+
+	return s.ObjectService.InitiateMultipartUpload(ctx, name, opt)
+}
+
+func (s *CryptoObjectService) UploadPart(ctx context.Context, name, uploadID string, partNumber int, r io.Reader, opt *cos.ObjectUploadPartOptions, cryptoCtx *CryptoContext) (*cos.Response, error) {
+	if cryptoCtx.PartSize == 0 {
+		return nil, fmt.Errorf("CryptoContext's PartSize is zero")
+	}
+	opt = cos.CloneObjectUploadPartOptions(opt)
+	if cryptoCtx.ContentCipher == nil {
+		return nil, fmt.Errorf("ContentCipher is nil, Please call the InitiateMultipartUpload")
+	}
+	totalBytes, err := cos.GetReaderLen(r)
+	if err == nil {
+		// 与 go http 保持一致, 非bytes.Buffer/bytes.Reader/strings.Reader需用户指定ContentLength
+		if opt != nil && opt.ContentLength == 0 && cos.IsLenReader(r) {
+			opt.ContentLength = totalBytes
+		}
+	}
+	cd := cryptoCtx.ContentCipher.GetCipherData().Clone()
+	cd.SeekIV(uint64(partNumber-1) * uint64(cryptoCtx.PartSize))
+	cc, err := cryptoCtx.ContentCipher.Clone(cd)
+	opt.ContentLength = cc.GetEncryptedLen(opt.ContentLength)
+	if err != nil {
+		return nil, err
+	}
+	reader, err := cc.EncryptContent(r)
+	if err != nil {
+		return nil, err
+	}
+	return s.ObjectService.UploadPart(ctx, name, uploadID, partNumber, reader, opt)
+}
diff --git a/crypto/crypto_object_part_test.go b/crypto/crypto_object_part_test.go
new file mode 100644
index 0000000..a708b2e
--- /dev/null
+++ b/crypto/crypto_object_part_test.go
@@ -0,0 +1,387 @@
+package coscrypto_test
+
+import (
+	"bytes"
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"github.com/stretchr/testify/assert"
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"github.com/tencentyun/cos-go-sdk-v5/crypto"
+	"io"
+	"io/ioutil"
+	math_rand "math/rand"
+	"net/http"
+	"net/url"
+	"os"
+	"sort"
+	"sync"
+	"time"
+)
+
+func (s *CosTestSuite) TestMultiUpload_Normal() {
+	name := "test/ObjectPut" + time.Now().Format(time.RFC3339)
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	v, _, err := s.CClient.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	assert.Nil(s.T(), err, "Init Failed")
+	chunks, _, err := cos.SplitSizeIntoChunks(contentLength, cryptoCtx.PartSize)
+	assert.Nil(s.T(), err, "Split Failed")
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	for _, chunk := range chunks {
+		opt := &cos.ObjectUploadPartOptions{
+			ContentLength: chunk.Size,
+		}
+		f := bytes.NewReader(originData[chunk.OffSet : chunk.OffSet+chunk.Size])
+		resp, err := s.CClient.Object.UploadPart(context.Background(), name, v.UploadID, chunk.Number, io.LimitReader(f, chunk.Size), opt, &cryptoCtx)
+		assert.Nil(s.T(), err, "UploadPart failed")
+		optcom.Parts = append(optcom.Parts, cos.Object{
+			PartNumber: chunk.Number, ETag: resp.Header.Get("ETag"),
+		})
+	}
+	_, _, err = s.CClient.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	assert.Nil(s.T(), err, "Complete Failed")
+
+	resp, err := s.CClient.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestMultiUpload_DecryptWithKey() {
+	name := "test/ObjectPut" + time.Now().Format(time.RFC3339)
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 分块上传
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	v, _, err := s.CClient.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	assert.Nil(s.T(), err, "Init Failed")
+	chunks, _, err := cos.SplitSizeIntoChunks(contentLength, cryptoCtx.PartSize)
+	assert.Nil(s.T(), err, "Split Failed")
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	for _, chunk := range chunks {
+		opt := &cos.ObjectUploadPartOptions{
+			ContentLength: chunk.Size,
+			Listener:      &cos.DefaultProgressListener{},
+		}
+		resp, err := s.CClient.Object.UploadPart(context.Background(), name, v.UploadID, chunk.Number, io.LimitReader(f, chunk.Size), opt, &cryptoCtx)
+		assert.Nil(s.T(), err, "UploadPart failed")
+		optcom.Parts = append(optcom.Parts, cos.Object{
+			PartNumber: chunk.Number, ETag: resp.Header.Get("ETag"),
+		})
+	}
+	_, _, err = s.CClient.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	assert.Nil(s.T(), err, "Complete Failed")
+
+	// 正常读取
+	resp, err := s.Client.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	encryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.NotEqual(s.T(), bytes.Compare(encryptedData, originData), 0, "encryptedData == originData")
+
+	// 获取解密信息
+	resp, err = s.CClient.Object.Head(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "HeadObject Failed")
+	cipherKey := resp.Header.Get(coscrypto.COSClientSideEncryptionKey)
+	cipherIV := resp.Header.Get(coscrypto.COSClientSideEncryptionStart)
+	key, err := s.Master.Decrypt([]byte(cipherKey))
+	assert.Nil(s.T(), err, "Master Decrypt Failed")
+	iv, err := s.Master.Decrypt([]byte(cipherIV))
+	assert.Nil(s.T(), err, "Master Decrypt Failed")
+
+	// 手动解密
+	block, err := aes.NewCipher(key)
+	assert.Nil(s.T(), err, "NewCipher Failed")
+	decrypter := cipher.NewCTR(block, iv)
+	decryptedData := make([]byte, len(originData))
+	decrypter.XORKeyStream(decryptedData, encryptedData)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestMultiUpload_PutFromFile() {
+	name := "test/ObjectPut" + time.Now().Format(time.RFC3339)
+	filepath := "tmpfile" + time.Now().Format(time.RFC3339)
+	newfile, err := os.Create(filepath)
+	assert.Nil(s.T(), err, "Create File Failed")
+	defer os.Remove(filepath)
+
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err = rand.Read(originData)
+	newfile.Write(originData)
+	newfile.Close()
+
+	m := md5.New()
+	m.Write(originData)
+	contentMD5 := m.Sum(nil)
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	v, _, err := s.CClient.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	assert.Nil(s.T(), err, "Init Failed")
+	_, chunks, _, err := cos.SplitFileIntoChunks(filepath, cryptoCtx.PartSize)
+	assert.Nil(s.T(), err, "Split Failed")
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	var wg sync.WaitGroup
+	var mtx sync.Mutex
+	for _, chunk := range chunks {
+		wg.Add(1)
+		go func(chk cos.Chunk) {
+			defer wg.Done()
+			fd, err := os.Open(filepath)
+			assert.Nil(s.T(), err, "Open File Failed")
+			opt := &cos.ObjectUploadPartOptions{
+				ContentLength: chk.Size,
+			}
+			fd.Seek(chk.OffSet, os.SEEK_SET)
+			resp, err := s.CClient.Object.UploadPart(context.Background(), name, v.UploadID, chk.Number, io.LimitReader(fd, chk.Size), opt, &cryptoCtx)
+			assert.Nil(s.T(), err, "UploadPart failed")
+			mtx.Lock()
+			optcom.Parts = append(optcom.Parts, cos.Object{
+				PartNumber: chk.Number, ETag: resp.Header.Get("ETag"),
+			})
+			mtx.Unlock()
+		}(chunk)
+	}
+	wg.Wait()
+	sort.Sort(cos.ObjectList(optcom.Parts))
+	_, _, err = s.CClient.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	assert.Nil(s.T(), err, "Complete Failed")
+
+	downfile := "downfile" + time.Now().Format(time.RFC3339)
+	_, err = s.CClient.Object.GetToFile(context.Background(), name, downfile, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+
+	m = md5.New()
+	fd, err := os.Open(downfile)
+	assert.Nil(s.T(), err, "Open File Failed")
+	defer os.Remove(downfile)
+	defer fd.Close()
+	io.Copy(m, fd)
+	downContentMD5 := m.Sum(nil)
+	assert.Equal(s.T(), bytes.Compare(contentMD5, downContentMD5), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestMultiUpload_GetWithRange() {
+	name := "test/ObjectPut" + time.Now().Format(time.RFC3339)
+	filepath := "tmpfile" + time.Now().Format(time.RFC3339)
+	newfile, err := os.Create(filepath)
+	assert.Nil(s.T(), err, "Create File Failed")
+	defer os.Remove(filepath)
+
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err = rand.Read(originData)
+	newfile.Write(originData)
+	newfile.Close()
+
+	m := md5.New()
+	m.Write(originData)
+	contentMD5 := m.Sum(nil)
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	iniopt := &cos.InitiateMultipartUploadOptions{
+		&cos.ACLHeaderOptions{
+			XCosACL: "private",
+		},
+		&cos.ObjectPutHeaderOptions{
+			ContentMD5:  base64.StdEncoding.EncodeToString(contentMD5),
+			XCosMetaXXX: &http.Header{},
+		},
+	}
+	iniopt.XCosMetaXXX.Add("x-cos-meta-isEncrypted", "true")
+
+	v, _, err := s.CClient.Object.InitiateMultipartUpload(context.Background(), name, iniopt, &cryptoCtx)
+	assert.Nil(s.T(), err, "Init Failed")
+	_, chunks, _, err := cos.SplitFileIntoChunks(filepath, cryptoCtx.PartSize)
+	assert.Nil(s.T(), err, "Split Failed")
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	var wg sync.WaitGroup
+	var mtx sync.Mutex
+	for _, chunk := range chunks {
+		wg.Add(1)
+		go func(chk cos.Chunk) {
+			defer wg.Done()
+			fd, err := os.Open(filepath)
+			assert.Nil(s.T(), err, "Open File Failed")
+			opt := &cos.ObjectUploadPartOptions{
+				ContentLength: chk.Size,
+			}
+			fd.Seek(chk.OffSet, os.SEEK_SET)
+			resp, err := s.CClient.Object.UploadPart(context.Background(), name, v.UploadID, chk.Number, io.LimitReader(fd, chk.Size), opt, &cryptoCtx)
+			assert.Nil(s.T(), err, "UploadPart failed")
+			mtx.Lock()
+			optcom.Parts = append(optcom.Parts, cos.Object{
+				PartNumber: chk.Number, ETag: resp.Header.Get("ETag"),
+			})
+			mtx.Unlock()
+		}(chunk)
+	}
+	wg.Wait()
+	sort.Sort(cos.ObjectList(optcom.Parts))
+	_, _, err = s.CClient.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	assert.Nil(s.T(), err, "Complete Failed")
+
+	// Range解密读取
+	for i := 0; i < 10; i++ {
+		math_rand.Seed(time.Now().UnixNano())
+		rangeStart := math_rand.Int63n(contentLength)
+		rangeEnd := rangeStart + math_rand.Int63n(contentLength-rangeStart)
+		if rangeEnd == rangeStart || rangeStart >= contentLength-1 {
+			continue
+		}
+		opt := &cos.ObjectGetOptions{
+			Range:    fmt.Sprintf("bytes=%v-%v", rangeStart, rangeEnd),
+			Listener: &cos.DefaultProgressListener{},
+		}
+		resp, err := s.CClient.Object.Get(context.Background(), name, opt)
+		assert.Nil(s.T(), err, "GetObject Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData[rangeStart:rangeEnd+1], decryptedData), 0, "decryptData != originData")
+	}
+
+	opt := &cos.ObjectGetOptions{
+		Listener: &cos.DefaultProgressListener{},
+	}
+	resp, err := s.CClient.Object.Get(context.Background(), name, opt)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	assert.Equal(s.T(), resp.Header.Get("x-cos-meta-isEncrypted"), "true", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionCekAlg), "AES/CTR/NoPadding", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionWrapAlg), "COS/KMS/Crypto", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionUnencryptedContentMD5), base64.StdEncoding.EncodeToString(contentMD5), "meta data isn't consistent")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestMultiUpload_GetWithNewClient() {
+	name := "test/ObjectPut" + time.Now().Format(time.RFC3339)
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	v, _, err := s.CClient.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	assert.Nil(s.T(), err, "Init Failed")
+	chunks, _, err := cos.SplitSizeIntoChunks(contentLength, cryptoCtx.PartSize)
+	assert.Nil(s.T(), err, "Split Failed")
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	for _, chunk := range chunks {
+		opt := &cos.ObjectUploadPartOptions{
+			ContentLength: chunk.Size,
+		}
+		f := bytes.NewReader(originData[chunk.OffSet : chunk.OffSet+chunk.Size])
+		resp, err := s.CClient.Object.UploadPart(context.Background(), name, v.UploadID, chunk.Number, io.LimitReader(f, chunk.Size), opt, &cryptoCtx)
+		assert.Nil(s.T(), err, "UploadPart failed")
+		optcom.Parts = append(optcom.Parts, cos.Object{
+			PartNumber: chunk.Number, ETag: resp.Header.Get("ETag"),
+		})
+	}
+	_, _, err = s.CClient.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	assert.Nil(s.T(), err, "Complete Failed")
+
+	u, _ := url.Parse("https://" + kBucket + ".cos." + kRegion + ".myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+		},
+	})
+	{
+		// 使用不同的MatDesc客户端读取, 期待错误
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test 2"
+		kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), resp, "Get Object Failed")
+		assert.NotNil(s.T(), err, "Get Object Failed")
+	}
+
+	{
+		// 使用相同的MatDesc客户端读取, 但KMSID不一样，期待正确，kms解密是不需要KMSID
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test"
+		kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, "KMSID", material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), err, "Get Object Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	}
+
+	{
+		// 使用相同的MatDesc客户端读取, 地域不一样，期待错误
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test"
+		diffRegion := "ap-shanghai"
+		if diffRegion == kRegion {
+			diffRegion = "ap-guangzhou"
+		}
+		kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), diffRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, "KMSID", material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), resp, "Get Object Failed")
+		assert.NotNil(s.T(), err, "Get Object Failed")
+	}
+
+	{
+		// 使用相同的MatDesc和KMSID客户端读取, 期待正确
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test"
+		kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), err, "Get Object Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	}
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
diff --git a/crypto/crypto_object_test.go b/crypto/crypto_object_test.go
new file mode 100644
index 0000000..54bc692
--- /dev/null
+++ b/crypto/crypto_object_test.go
@@ -0,0 +1,385 @@
+package coscrypto_test
+
+import (
+	"bytes"
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"github.com/tencentyun/cos-go-sdk-v5/crypto"
+	"io"
+	"io/ioutil"
+	math_rand "math/rand"
+	"net/http"
+	"net/url"
+	"os"
+	"testing"
+	"time"
+)
+
+const (
+	kAppid  = 1259654469
+	kBucket = "cosgosdktest-1259654469"
+	kRegion = "ap-guangzhou"
+)
+
+type CosTestSuite struct {
+	suite.Suite
+	Client  *cos.Client
+	CClient *coscrypto.CryptoClient
+	Master  coscrypto.MasterCipher
+}
+
+func (s *CosTestSuite) SetupSuite() {
+	u, _ := url.Parse("https://" + kBucket + ".cos." + kRegion + ".myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	s.Client = cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+		},
+	})
+	material := make(map[string]string)
+	material["desc"] = "cos crypto suite test"
+	kmsclient, _ := coscrypto.NewKMSClient(s.Client.GetCredential(), kRegion)
+	s.Master, _ = coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), material)
+	s.CClient = coscrypto.NewCryptoClient(s.Client, s.Master)
+	opt := &cos.BucketPutOptions{
+		XCosACL: "public-read",
+	}
+	r, err := s.Client.Bucket.Put(context.Background(), opt)
+	if err != nil && r != nil && r.StatusCode == 409 {
+		fmt.Println("BucketAlreadyOwnedByYou")
+	} else if err != nil {
+		assert.Nil(s.T(), err, "PutBucket Failed")
+	}
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_DecryptWithKey_10MB() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	originData := make([]byte, 1024*1024*10+1)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 加密存储
+	_, err = s.CClient.Object.Put(context.Background(), name, f, nil)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// 获取解密信息
+	resp, err := s.CClient.Object.Head(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "HeadObject Failed")
+	cipherKey := resp.Header.Get(coscrypto.COSClientSideEncryptionKey)
+	cipherIV := resp.Header.Get(coscrypto.COSClientSideEncryptionStart)
+	key, err := s.Master.Decrypt([]byte(cipherKey))
+	assert.Nil(s.T(), err, "Master Decrypt Failed")
+	iv, err := s.Master.Decrypt([]byte(cipherIV))
+	assert.Nil(s.T(), err, "Master Decrypt Failed")
+
+	// 正常读取
+	resp, err = s.Client.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	encryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.NotEqual(s.T(), bytes.Compare(encryptedData, originData), 0, "encryptedData == originData")
+
+	// 手动解密
+	block, err := aes.NewCipher(key)
+	assert.Nil(s.T(), err, "NewCipher Failed")
+	decrypter := cipher.NewCTR(block, iv)
+	decryptedData := make([]byte, len(originData))
+	decrypter.XORKeyStream(decryptedData, encryptedData)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_Normal_10MB() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	originData := make([]byte, 1024*1024*10+1)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 加密存储
+	_, err = s.CClient.Object.Put(context.Background(), name, f, nil)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// 解密读取
+	resp, err := s.CClient.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_ZeroFile() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	// 加密存储
+	_, err := s.CClient.Object.Put(context.Background(), name, bytes.NewReader([]byte("")), nil)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// 解密读取
+	resp, err := s.CClient.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare([]byte(""), decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_WithMetaData() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	originData := make([]byte, 1024*1024*10+1)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	m := md5.New()
+	m.Write(originData)
+	contentMD5 := m.Sum(nil)
+	opt := &cos.ObjectPutOptions{
+		&cos.ACLHeaderOptions{
+			XCosACL: "private",
+		},
+		&cos.ObjectPutHeaderOptions{
+			ContentLength: 1024*1024*10 + 1,
+			ContentMD5:    base64.StdEncoding.EncodeToString(contentMD5),
+			XCosMetaXXX:   &http.Header{},
+		},
+	}
+	opt.XCosMetaXXX.Add("x-cos-meta-isEncrypted", "true")
+	// 加密存储
+	_, err = s.CClient.Object.Put(context.Background(), name, f, opt)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// 解密读取
+	resp, err := s.CClient.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	assert.Equal(s.T(), resp.Header.Get("x-cos-meta-isEncrypted"), "true", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionCekAlg), "AES/CTR/NoPadding", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionWrapAlg), "COS/KMS/Crypto", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionUnencryptedContentMD5), base64.StdEncoding.EncodeToString(contentMD5), "meta data isn't consistent")
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_ByFile() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	filepath := "tmpfile" + time.Now().Format(time.RFC3339)
+	newfile, err := os.Create(filepath)
+	assert.Nil(s.T(), err, "Create File Failed")
+	defer os.Remove(filepath)
+
+	originData := make([]byte, 1024*1024*10+1)
+	_, err = rand.Read(originData)
+	newfile.Write(originData)
+	newfile.Close()
+
+	m := md5.New()
+	m.Write(originData)
+	contentMD5 := m.Sum(nil)
+	opt := &cos.ObjectPutOptions{
+		&cos.ACLHeaderOptions{
+			XCosACL: "private",
+		},
+		&cos.ObjectPutHeaderOptions{
+			ContentLength: 1024*1024*10 + 1,
+			ContentMD5:    base64.StdEncoding.EncodeToString(contentMD5),
+			XCosMetaXXX:   &http.Header{},
+		},
+	}
+	opt.XCosMetaXXX.Add("x-cos-meta-isEncrypted", "true")
+	// 加密存储
+	_, err = s.CClient.Object.PutFromFile(context.Background(), name, filepath, opt)
+	assert.Nil(s.T(), err, "PutFromFile Failed")
+
+	// 解密读取
+	downfile := "downfile" + time.Now().Format(time.RFC3339)
+	resp, err := s.CClient.Object.GetToFile(context.Background(), name, downfile, nil)
+	assert.Nil(s.T(), err, "GetToFile Failed")
+	assert.Equal(s.T(), resp.Header.Get("x-cos-meta-isEncrypted"), "true", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionCekAlg), "AES/CTR/NoPadding", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionWrapAlg), "COS/KMS/Crypto", "meta data isn't consistent")
+	assert.Equal(s.T(), resp.Header.Get(coscrypto.COSClientSideEncryptionUnencryptedContentMD5), base64.StdEncoding.EncodeToString(contentMD5), "meta data isn't consistent")
+
+	fd, err := os.Open(downfile)
+	assert.Nil(s.T(), err, "Open File Failed")
+	defer os.Remove(downfile)
+	defer fd.Close()
+	m = md5.New()
+	io.Copy(m, fd)
+	downContentMD5 := m.Sum(nil)
+	assert.Equal(s.T(), bytes.Compare(contentMD5, downContentMD5), 0, "decryptData != originData")
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_DecryptWithNewClient_10MB() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	originData := make([]byte, 1024*1024*10+1)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 加密存储
+	_, err = s.CClient.Object.Put(context.Background(), name, f, nil)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	u, _ := url.Parse("https://" + kBucket + ".cos." + kRegion + ".myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+		},
+	})
+	{
+		// 使用不同的MatDesc客户端读取, 期待错误
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test 2"
+		kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), resp, "Get Object Failed")
+		assert.NotNil(s.T(), err, "Get Object Failed")
+	}
+
+	{
+		// 使用相同的MatDesc客户端读取, 但KMSID不一样，期待正确，kms解密是不需要KMSID
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test"
+		kmsclient, _ := coscrypto.NewKMSClient(s.Client.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, "KMSID", material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), err, "Get Object Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	}
+
+	{
+		// 使用相同的MatDesc和KMSID客户端读取, 期待正确
+		material := make(map[string]string)
+		material["desc"] = "cos crypto suite test"
+		kmsclient, _ := coscrypto.NewKMSClient(s.Client.GetCredential(), kRegion)
+		master, _ := coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), material)
+		client := coscrypto.NewCryptoClient(c, master)
+		resp, err := client.Object.Get(context.Background(), name, nil)
+		assert.Nil(s.T(), err, "Get Object Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+	}
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_RangeGet() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	contentLength := 1024*1024*10 + 1
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 加密存储
+	_, err = s.CClient.Object.Put(context.Background(), name, f, nil)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// Range解密读取
+	for i := 0; i < 10; i++ {
+		math_rand.Seed(time.Now().UnixNano())
+		rangeStart := math_rand.Intn(contentLength)
+		rangeEnd := rangeStart + math_rand.Intn(contentLength-rangeStart)
+		if rangeEnd == rangeStart || rangeStart >= contentLength-1 {
+			continue
+		}
+		opt := &cos.ObjectGetOptions{
+			Range: fmt.Sprintf("bytes=%v-%v", rangeStart, rangeEnd),
+		}
+		resp, err := s.CClient.Object.Get(context.Background(), name, opt)
+		assert.Nil(s.T(), err, "GetObject Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData[rangeStart:rangeEnd+1], decryptedData), 0, "decryptData != originData")
+	}
+
+	// 解密读取
+	resp, err := s.CClient.Object.Get(context.Background(), name, nil)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func (s *CosTestSuite) TestPutGetDeleteObject_WithListenerAndRange() {
+	name := "test/objectPut" + time.Now().Format(time.RFC3339)
+	contentLength := 1024*1024*10 + 1
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+
+	// 加密存储
+	popt := &cos.ObjectPutOptions{
+		nil,
+		&cos.ObjectPutHeaderOptions{
+			Listener: &cos.DefaultProgressListener{},
+		},
+	}
+	_, err = s.CClient.Object.Put(context.Background(), name, f, popt)
+	assert.Nil(s.T(), err, "PutObject Failed")
+
+	// Range解密读取
+	for i := 0; i < 10; i++ {
+		math_rand.Seed(time.Now().UnixNano())
+		rangeStart := math_rand.Intn(contentLength)
+		rangeEnd := rangeStart + math_rand.Intn(contentLength-rangeStart)
+		if rangeEnd == rangeStart || rangeStart >= contentLength-1 {
+			continue
+		}
+		opt := &cos.ObjectGetOptions{
+			Range:    fmt.Sprintf("bytes=%v-%v", rangeStart, rangeEnd),
+			Listener: &cos.DefaultProgressListener{},
+		}
+		resp, err := s.CClient.Object.Get(context.Background(), name, opt)
+		assert.Nil(s.T(), err, "GetObject Failed")
+		defer resp.Body.Close()
+		decryptedData, _ := ioutil.ReadAll(resp.Body)
+		assert.Equal(s.T(), bytes.Compare(originData[rangeStart:rangeEnd+1], decryptedData), 0, "decryptData != originData")
+	}
+	// 解密读取
+	opt := &cos.ObjectGetOptions{
+		Listener: &cos.DefaultProgressListener{},
+	}
+	resp, err := s.CClient.Object.Get(context.Background(), name, opt)
+	assert.Nil(s.T(), err, "GetObject Failed")
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "decryptData != originData")
+
+	_, err = s.CClient.Object.Delete(context.Background(), name)
+	assert.Nil(s.T(), err, "DeleteObject Failed")
+}
+
+func TestCosTestSuite(t *testing.T) {
+	suite.Run(t, new(CosTestSuite))
+}
+
+func (s *CosTestSuite) TearDownSuite() {
+}
diff --git a/crypto/crypto_type.go b/crypto/crypto_type.go
new file mode 100644
index 0000000..f12557e
--- /dev/null
+++ b/crypto/crypto_type.go
@@ -0,0 +1,141 @@
+package coscrypto
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"io"
+	math_rand "math/rand"
+	"time"
+)
+
+const (
+	COSClientSideEncryptionKey                      string = "x-cos-meta-client-side-encryption-key"
+	COSClientSideEncryptionStart                           = "x-cos-meta-client-side-encryption-start"
+	COSClientSideEncryptionCekAlg                          = "x-cos-meta-client-side-encryption-cek-alg"
+	COSClientSideEncryptionWrapAlg                         = "x-cos-meta-client-side-encryption-wrap-alg"
+	COSClientSideEncryptionMatDesc                         = "x-cos-meta-client-side-encryption-matdesc"
+	COSClientSideEncryptionUnencryptedContentLength        = "x-cos-meta-client-side-encryption-unencrypted-content-length"
+	COSClientSideEncryptionUnencryptedContentMD5           = "x-cos-meta-client-side-encryption-unencrypted-content-md5"
+	COSClientSideEncryptionDataSize                        = "x-cos-meta-client-side-encryption-data-size"
+	COSClientSideEncryptionPartSize                        = "x-cos-meta-client-side-encryption-part-size"
+	COSClientUserAgent                                     = "User-Agent"
+)
+
+const (
+	CosKmsCryptoWrap   = "COS/KMS/Crypto"
+	AesCtrAlgorithm    = "AES/CTR/NoPadding"
+	EncryptionUaSuffix = "COSEncryptionClient"
+)
+
+type MasterCipher interface {
+	Encrypt([]byte) ([]byte, error)
+	Decrypt([]byte) ([]byte, error)
+	GetWrapAlgorithm() string
+	GetMatDesc() string
+}
+
+type ContentCipherBuilder interface {
+	ContentCipher() (ContentCipher, error)
+	ContentCipherEnv(Envelope) (ContentCipher, error)
+	GetMatDesc() string
+}
+
+type ContentCipher interface {
+	EncryptContent(io.Reader) (io.ReadCloser, error)
+	DecryptContent(io.Reader) (io.ReadCloser, error)
+	Clone(cd CipherData) (ContentCipher, error)
+	GetEncryptedLen(int64) int64
+	GetCipherData() *CipherData
+	GetAlignLen() int
+}
+
+type Envelope struct {
+	IV                    string
+	CipherKey             string
+	MatDesc               string
+	WrapAlg               string
+	CEKAlg                string
+	UnencryptedMD5        string
+	UnencryptedContentLen string
+}
+
+func (el Envelope) IsValid() bool {
+	return len(el.IV) > 0 &&
+		len(el.CipherKey) > 0 &&
+		len(el.WrapAlg) > 0 &&
+		len(el.CEKAlg) > 0
+}
+
+func (el Envelope) String() string {
+	return fmt.Sprintf("IV=%s&CipherKey=%s&WrapAlg=%s&CEKAlg=%s", el.IV, el.CipherKey, el.WrapAlg, el.CEKAlg)
+}
+
+type CipherData struct {
+	IV            []byte
+	Key           []byte
+	MatDesc       string
+	WrapAlgorithm string
+	CEKAlgorithm  string
+	EncryptedIV   []byte
+	EncryptedKey  []byte
+}
+
+func (cd *CipherData) RandomKeyIv(keyLen int, ivLen int) error {
+	math_rand.Seed(time.Now().UnixNano())
+
+	// Key
+	cd.Key = make([]byte, keyLen)
+	if _, err := io.ReadFull(rand.Reader, cd.Key); err != nil {
+		return err
+	}
+
+	// sizeof uint64
+	if ivLen < 8 {
+		return fmt.Errorf("ivLen:%d less than 8", ivLen)
+	}
+
+	// IV: | nonce: 8 bytes | Serial number: 8 bytes |
+	cd.IV = make([]byte, ivLen)
+	if _, err := io.ReadFull(rand.Reader, cd.IV[0:ivLen-8]); err != nil {
+		return err
+	}
+
+	// only use 4 byte,in order not to overflow when SeekIV()
+	randNumber := math_rand.Uint32()
+	cd.SetIV(uint64(randNumber))
+	return nil
+}
+
+func (cd *CipherData) SetIV(iv uint64) {
+	ivLen := len(cd.IV)
+	binary.BigEndian.PutUint64(cd.IV[ivLen-8:], iv)
+}
+
+func (cd *CipherData) GetIV() uint64 {
+	ivLen := len(cd.IV)
+	return binary.BigEndian.Uint64(cd.IV[ivLen-8:])
+}
+
+func (cd *CipherData) SeekIV(startPos uint64) {
+	cd.SetIV(cd.GetIV() + startPos/uint64(len(cd.IV)))
+}
+
+func (cd *CipherData) Clone() CipherData {
+	var cloneCd CipherData
+	cloneCd = *cd
+
+	cloneCd.Key = make([]byte, len(cd.Key))
+	copy(cloneCd.Key, cd.Key)
+
+	cloneCd.IV = make([]byte, len(cd.IV))
+	copy(cloneCd.IV, cd.IV)
+
+	cloneCd.EncryptedIV = make([]byte, len(cd.EncryptedIV))
+	copy(cloneCd.EncryptedIV, cd.EncryptedIV)
+
+	cloneCd.EncryptedKey = make([]byte, len(cd.EncryptedKey))
+	copy(cloneCd.EncryptedKey, cd.EncryptedKey)
+
+	return cloneCd
+}
diff --git a/crypto/master_kms_cipher.go b/crypto/master_kms_cipher.go
new file mode 100644
index 0000000..011458e
--- /dev/null
+++ b/crypto/master_kms_cipher.go
@@ -0,0 +1,87 @@
+package coscrypto
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+
+	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common"
+	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common/profile"
+	kms "github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/kms/v20190118"
+	"github.com/tencentyun/cos-go-sdk-v5"
+)
+
+const (
+	KMSEndPoint = "kms.tencentcloudapi.com"
+)
+
+type MasterKMSCipher struct {
+	Client  *kms.Client
+	KmsId   string
+	MatDesc string
+}
+
+func NewKMSClient(cred *cos.Credential, region string) (*kms.Client, error) {
+	if cred == nil {
+		fmt.Errorf("credential is nil")
+	}
+	credential := common.NewTokenCredential(
+		cred.SecretID,
+		cred.SecretKey,
+		cred.SessionToken,
+	)
+	cpf := profile.NewClientProfile()
+	cpf.HttpProfile.Endpoint = KMSEndPoint
+	client, err := kms.NewClient(credential, region, cpf)
+	return client, err
+}
+
+func CreateMasterKMS(client *kms.Client, kmsId string, desc map[string]string) (MasterCipher, error) {
+	if kmsId == "" || client == nil {
+		return nil, fmt.Errorf("KMS ID is empty or kms client is nil")
+	}
+	var kmsCipher MasterKMSCipher
+	var jdesc string
+	if len(desc) > 0 {
+		bs, err := json.Marshal(desc)
+		if err != nil {
+			return nil, err
+		}
+		jdesc = string(bs)
+	}
+	kmsCipher.Client = client
+	kmsCipher.KmsId = kmsId
+	kmsCipher.MatDesc = jdesc
+	return &kmsCipher, nil
+}
+
+func (kc *MasterKMSCipher) Encrypt(plaintext []byte) ([]byte, error) {
+	request := kms.NewEncryptRequest()
+	request.KeyId = common.StringPtr(kc.KmsId)
+	request.EncryptionContext = common.StringPtr(kc.MatDesc)
+	request.Plaintext = common.StringPtr(base64.StdEncoding.EncodeToString(plaintext))
+	resp, err := kc.Client.Encrypt(request)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(*resp.Response.CiphertextBlob), nil
+}
+
+func (kc *MasterKMSCipher) Decrypt(ciphertext []byte) ([]byte, error) {
+	request := kms.NewDecryptRequest()
+	request.CiphertextBlob = common.StringPtr(string(ciphertext))
+	request.EncryptionContext = common.StringPtr(kc.MatDesc)
+	resp, err := kc.Client.Decrypt(request)
+	if err != nil {
+		return nil, err
+	}
+	return base64.StdEncoding.DecodeString(*resp.Response.Plaintext)
+}
+
+func (kc *MasterKMSCipher) GetWrapAlgorithm() string {
+	return CosKmsCryptoWrap
+}
+
+func (kc *MasterKMSCipher) GetMatDesc() string {
+	return kc.MatDesc
+}
diff --git a/crypto/master_kms_cipher_test.go b/crypto/master_kms_cipher_test.go
new file mode 100644
index 0000000..2fafe9a
--- /dev/null
+++ b/crypto/master_kms_cipher_test.go
@@ -0,0 +1,91 @@
+package coscrypto_test
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common"
+	kms "github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/kms/v20190118"
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"github.com/tencentyun/cos-go-sdk-v5/crypto"
+	"os"
+)
+
+func (s *CosTestSuite) TestMasterKmsCipher_TestKmsClient() {
+	kmsclient, _ := coscrypto.NewKMSClient(&cos.Credential{
+		SecretID:  os.Getenv("COS_SECRETID"),
+		SecretKey: os.Getenv("COS_SECRETKEY"),
+	}, kRegion)
+
+	originData := make([]byte, 1024)
+	_, err := rand.Read(originData)
+
+	ctx := make(map[string]string)
+	ctx["desc"] = string(originData[:10])
+	bs, _ := json.Marshal(ctx)
+	ctxJson := string(bs)
+	enReq := kms.NewEncryptRequest()
+	enReq.KeyId = common.StringPtr(os.Getenv("KMSID"))
+	enReq.EncryptionContext = common.StringPtr(ctxJson)
+	enReq.Plaintext = common.StringPtr(base64.StdEncoding.EncodeToString(originData))
+	enResp, err := kmsclient.Encrypt(enReq)
+	assert.Nil(s.T(), err, "Encrypt Failed")
+	encryptedData := []byte(*enResp.Response.CiphertextBlob)
+
+	deReq := kms.NewDecryptRequest()
+	deReq.CiphertextBlob = common.StringPtr(string(encryptedData))
+	deReq.EncryptionContext = common.StringPtr(ctxJson)
+	deResp, err := kmsclient.Decrypt(deReq)
+	assert.Nil(s.T(), err, "Decrypt Failed")
+	decryptedData, err := base64.StdEncoding.DecodeString(*deResp.Response.Plaintext)
+	assert.Nil(s.T(), err, "base64 Decode Failed")
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "originData != decryptedData")
+}
+
+func (s *CosTestSuite) TestMasterKmsCipher_TestNormal() {
+	kmsclient, _ := coscrypto.NewKMSClient(&cos.Credential{
+		SecretID:  os.Getenv("COS_SECRETID"),
+		SecretKey: os.Getenv("COS_SECRETKEY"),
+	}, kRegion)
+
+	desc := make(map[string]string)
+	desc["test"] = "TestMasterKmsCipher_TestNormal"
+	master, err := coscrypto.CreateMasterKMS(kmsclient, os.Getenv("KMSID"), desc)
+	assert.Nil(s.T(), err, "CreateMasterKMS Failed")
+
+	originData := make([]byte, 1024)
+	_, err = rand.Read(originData)
+
+	encryptedData, err := master.Encrypt(originData)
+	assert.Nil(s.T(), err, "Encrypt Failed")
+
+	decryptedData, err := master.Decrypt(encryptedData)
+	assert.Nil(s.T(), err, "Decrypt Failed")
+
+	assert.Equal(s.T(), bytes.Compare(originData, decryptedData), 0, "originData != decryptedData")
+}
+
+func (s *CosTestSuite) TestMasterKmsCipher_TestError() {
+	kmsclient, _ := coscrypto.NewKMSClient(&cos.Credential{
+		SecretID:  os.Getenv("COS_SECRETID"),
+		SecretKey: os.Getenv("COS_SECRETKEY"),
+	}, kRegion)
+
+	desc := make(map[string]string)
+	desc["test"] = "TestMasterKmsCipher_TestNormal"
+	master, err := coscrypto.CreateMasterKMS(kmsclient, "ErrorKMSID", desc)
+	assert.Nil(s.T(), err, "CreateMasterKMS Failed")
+
+	originData := make([]byte, 1024)
+	_, err = rand.Read(originData)
+
+	encryptedData, err := master.Encrypt(originData)
+	assert.NotNil(s.T(), err, "Encrypt Failed")
+
+	decryptedData, err := master.Decrypt(encryptedData)
+	assert.NotNil(s.T(), err, "Decrypt Failed")
+
+	assert.NotEqual(s.T(), bytes.Compare(originData, decryptedData), 0, "originData != decryptedData")
+}
diff --git a/example/crypto/crypto_sample.go b/example/crypto/crypto_sample.go
new file mode 100644
index 0000000..54672ea
--- /dev/null
+++ b/example/crypto/crypto_sample.go
@@ -0,0 +1,305 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/md5"
+	"crypto/rand"
+	"fmt"
+	"io"
+	"io/ioutil"
+	math_rand "math/rand"
+	"net/http"
+	"net/url"
+	"os"
+	"time"
+
+	"github.com/tencentyun/cos-go-sdk-v5"
+	"github.com/tencentyun/cos-go-sdk-v5/crypto"
+	"github.com/tencentyun/cos-go-sdk-v5/debug"
+)
+
+func log_status(err error) {
+	if err == nil {
+		return
+	}
+	if cos.IsNotFoundError(err) {
+		// WARN
+		fmt.Println("WARN: Resource is not existed")
+	} else if e, ok := cos.IsCOSError(err); ok {
+		fmt.Printf("ERROR: Code: %v\n", e.Code)
+		fmt.Printf("ERROR: Message: %v\n", e.Message)
+		fmt.Printf("ERROR: Resource: %v\n", e.Resource)
+		fmt.Printf("ERROR: RequestId: %v\n", e.RequestID)
+		// ERROR
+	} else {
+		fmt.Printf("ERROR: %v\n", err)
+		// ERROR
+	}
+	os.Exit(1)
+}
+
+func simple_put_object() {
+	u, _ := url.Parse("https://test-1259654469.cos.ap-guangzhou.myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+			Transport: &debug.DebugRequestTransport{
+				RequestHeader:  true,
+				RequestBody:    false,
+				ResponseHeader: true,
+				ResponseBody:   false,
+			},
+		},
+	})
+	// Case1 上传对象
+	name := "test/example2"
+
+	fmt.Println("============== simple_put_object ======================")
+	// 该标识信息唯一确认一个主加密密钥, 解密时，需要传入相同的标识信息
+	materialDesc := make(map[string]string)
+	materialDesc["desc"] = "<material information of your master encrypt key>"
+
+	// 创建KMS客户端
+	kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), "ap-guangzhou")
+	// 创建KMS主加密密钥，标识信息和主密钥一一对应
+	kmsID := os.Getenv("KMSID")
+	masterCipher, _ := coscrypto.CreateMasterKMS(kmsclient, kmsID, materialDesc)
+	// 创建加密客户端
+	client := coscrypto.NewCryptoClient(c, masterCipher)
+
+	contentLength := 1024*1024*10 + 1
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+	f := bytes.NewReader(originData)
+	// 加密上传
+	_, err = client.Object.Put(context.Background(), name, f, nil)
+	log_status(err)
+
+	math_rand.Seed(time.Now().UnixNano())
+	rangeStart := math_rand.Intn(contentLength)
+	rangeEnd := rangeStart + math_rand.Intn(contentLength-rangeStart)
+	opt := &cos.ObjectGetOptions{
+		Range: fmt.Sprintf("bytes=%v-%v", rangeStart, rangeEnd),
+	}
+	// 解密下载
+	resp, err := client.Object.Get(context.Background(), name, opt)
+	log_status(err)
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	if bytes.Compare(decryptedData, originData[rangeStart:rangeEnd+1]) != 0 {
+		fmt.Println("Error: encryptedData != originData")
+	}
+}
+
+func simple_put_object_from_file() {
+	u, _ := url.Parse("https://test-1259654469.cos.ap-guangzhou.myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+			Transport: &debug.DebugRequestTransport{
+				RequestHeader:  true,
+				RequestBody:    false,
+				ResponseHeader: true,
+				ResponseBody:   false,
+			},
+		},
+	})
+	// Case1 上传对象
+	name := "test/example1"
+
+	fmt.Println("============== simple_put_object_from_file ======================")
+	// 该标识信息唯一确认一个主加密密钥, 解密时，需要传入相同的标识信息
+	materialDesc := make(map[string]string)
+	materialDesc["desc"] = "<material information of your master encrypt key>"
+
+	// 创建KMS客户端
+	kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), "ap-guangzhou")
+	// 创建KMS主加密密钥，标识信息和主密钥一一对应
+	kmsID := os.Getenv("KMSID")
+	masterCipher, _ := coscrypto.CreateMasterKMS(kmsclient, kmsID, materialDesc)
+	// 创建加密客户端
+	client := coscrypto.NewCryptoClient(c, masterCipher)
+
+	filepath := "test"
+	fd, err := os.Open(filepath)
+	log_status(err)
+	defer fd.Close()
+	m := md5.New()
+	io.Copy(m, fd)
+	originDataMD5 := m.Sum(nil)
+
+	// 加密上传
+	_, err = client.Object.PutFromFile(context.Background(), name, filepath, nil)
+	log_status(err)
+
+	// 解密下载
+	_, err = client.Object.GetToFile(context.Background(), name, "./test.download", nil)
+	log_status(err)
+
+	fd, err = os.Open("./test.download")
+	log_status(err)
+	defer fd.Close()
+	m = md5.New()
+	io.Copy(m, fd)
+	decryptedDataMD5 := m.Sum(nil)
+
+	if bytes.Compare(decryptedDataMD5, originDataMD5) != 0 {
+		fmt.Println("Error: encryptedData != originData")
+	}
+}
+
+func multi_put_object() {
+	u, _ := url.Parse("https://test-1259654469.cos.ap-guangzhou.myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+			Transport: &debug.DebugRequestTransport{
+				RequestHeader:  true,
+				RequestBody:    false,
+				ResponseHeader: true,
+				ResponseBody:   false,
+			},
+		},
+	})
+	// Case1 上传对象
+	name := "test/example1"
+
+	fmt.Println("============== multi_put_object ======================")
+	// 该标识信息唯一确认一个主加密密钥, 解密时，需要传入相同的标识信息
+	materialDesc := make(map[string]string)
+	materialDesc["desc"] = "<material information of your master encrypt key>"
+
+	// 创建KMS客户端
+	kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), "ap-guangzhou")
+	// 创建KMS主加密密钥，标识信息和主密钥一一对应
+	kmsID := os.Getenv("KMSID")
+	masterCipher, _ := coscrypto.CreateMasterKMS(kmsclient, kmsID, materialDesc)
+	// 创建加密客户端
+	client := coscrypto.NewCryptoClient(c, masterCipher)
+
+	contentLength := int64(1024*1024*10 + 1)
+	originData := make([]byte, contentLength)
+	_, err := rand.Read(originData)
+	log_status(err)
+
+	// 分块上传
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		// 每个分块需要16字节对齐
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	v, _, err := client.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	log_status(err)
+	// 切分数据
+	chunks, _, err := cos.SplitSizeIntoChunks(contentLength, cryptoCtx.PartSize)
+	log_status(err)
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	for _, chunk := range chunks {
+		opt := &cos.ObjectUploadPartOptions{
+			ContentLength: chunk.Size,
+		}
+		f := bytes.NewReader(originData[chunk.OffSet : chunk.OffSet+chunk.Size])
+		resp, err := client.Object.UploadPart(context.Background(), name, v.UploadID, chunk.Number, f, opt, &cryptoCtx)
+		log_status(err)
+		optcom.Parts = append(optcom.Parts, cos.Object{
+			PartNumber: chunk.Number, ETag: resp.Header.Get("ETag"),
+		})
+	}
+	_, _, err = client.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	log_status(err)
+
+	resp, err := client.Object.Get(context.Background(), name, nil)
+	log_status(err)
+	defer resp.Body.Close()
+	decryptedData, _ := ioutil.ReadAll(resp.Body)
+	if bytes.Compare(decryptedData, originData) != 0 {
+		fmt.Println("Error: encryptedData != originData")
+	}
+}
+
+func multi_put_object_from_file() {
+	u, _ := url.Parse("https://test-1259654469.cos.ap-guangzhou.myqcloud.com")
+	b := &cos.BaseURL{BucketURL: u}
+	c := cos.NewClient(b, &http.Client{
+		Transport: &cos.AuthorizationTransport{
+			SecretID:  os.Getenv("COS_SECRETID"),
+			SecretKey: os.Getenv("COS_SECRETKEY"),
+			Transport: &debug.DebugRequestTransport{
+				RequestHeader:  true,
+				RequestBody:    false,
+				ResponseHeader: true,
+				ResponseBody:   false,
+			},
+		},
+	})
+	// Case1 上传对象
+	name := "test/example1"
+
+	fmt.Println("============== multi_put_object_from_file ======================")
+	// 该标识信息唯一确认一个主加密密钥, 解密时，需要传入相同的标识信息
+	materialDesc := make(map[string]string)
+	materialDesc["desc"] = "<material information of your master encrypt key>"
+
+	// 创建KMS客户端
+	kmsclient, _ := coscrypto.NewKMSClient(c.GetCredential(), "ap-guangzhou")
+	// 创建KMS主加密密钥，标识信息和主密钥一一对应
+	kmsID := os.Getenv("KMSID")
+	masterCipher, _ := coscrypto.CreateMasterKMS(kmsclient, kmsID, materialDesc)
+	// 创建加密客户端
+	client := coscrypto.NewCryptoClient(c, masterCipher)
+
+	filepath := "test"
+	stat, err := os.Stat(filepath)
+	log_status(err)
+	contentLength := stat.Size()
+
+	// 分块上传
+	cryptoCtx := coscrypto.CryptoContext{
+		DataSize: contentLength,
+		// 每个分块需要16字节对齐
+		PartSize: (contentLength / 16 / 3) * 16,
+	}
+	// 切分数据
+	_, chunks, _, err := cos.SplitFileIntoChunks(filepath, cryptoCtx.PartSize)
+	log_status(err)
+
+	// init mulitupload
+	v, _, err := client.Object.InitiateMultipartUpload(context.Background(), name, nil, &cryptoCtx)
+	log_status(err)
+
+	// part upload
+	optcom := &cos.CompleteMultipartUploadOptions{}
+	for _, chunk := range chunks {
+		fd, err := os.Open(filepath)
+		log_status(err)
+		opt := &cos.ObjectUploadPartOptions{
+			ContentLength: chunk.Size,
+		}
+		fd.Seek(chunk.OffSet, os.SEEK_SET)
+		resp, err := client.Object.UploadPart(context.Background(), name, v.UploadID, chunk.Number, io.LimitReader(fd, chunk.Size), opt, &cryptoCtx)
+		log_status(err)
+		optcom.Parts = append(optcom.Parts, cos.Object{
+			PartNumber: chunk.Number, ETag: resp.Header.Get("ETag"),
+		})
+	}
+	// complete upload
+	_, _, err = client.Object.CompleteMultipartUpload(context.Background(), name, v.UploadID, optcom)
+	log_status(err)
+
+	_, err = client.Object.GetToFile(context.Background(), name, "test.download", nil)
+	log_status(err)
+}
+
+func main() {
+	simple_put_object()
+	simple_put_object_from_file()
+	multi_put_object()
+	multi_put_object_from_file()
+}