diff --git a/accessEntity/data.go b/accessEntity/data.go
index 3e808b0..3981014 100644
--- a/accessEntity/data.go
+++ b/accessEntity/data.go
@@ -27,6 +27,7 @@
 
 type DbManager struct {
 	common.DbManager
+	cipherManager common.CipherManagerInterface
 }
 
 func (d *DbManager) GetApiProductNames(id string, idType string) ([]string, error) {
diff --git a/common/cipher.go b/common/cipher.go
new file mode 100644
index 0000000..dcd3eec
--- /dev/null
+++ b/common/cipher.go
@@ -0,0 +1,168 @@
+// Copyright 2017 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package common
+
+import (
+	"encoding/base64"
+	"fmt"
+	"github.com/apid/apid-core/cipher"
+	"io/ioutil"
+	"net/http"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+const RegEncrypted = `^\{[0-9A-Za-z]+/[0-9A-Za-z]+/[0-9A-Za-z]+\}.`
+const retrieveEncryptKeyPath = ""
+
+var RegexpEncrypted = regexp.MustCompile(RegEncrypted)
+
+const (
+	EncryptAes = "AES"
+)
+
+type KmsCipherManager struct {
+	// org-level key map {organization: key}
+	key map[string][]byte
+	// org-level AesCipher map {organization: AesCipher}
+	aes    map[string]*cipher.AesCipher
+	mutex  *sync.RWMutex
+	client *http.Client
+}
+
+func (c *KmsCipherManager) retrieveKey(org string) (key []byte, err error) {
+	req, err := http.NewRequest(http.MethodGet, retrieveEncryptKeyPath, nil)
+	if err != nil {
+		return
+	}
+	res, err := c.client.Do(req)
+	if err != nil {
+		return
+	}
+	if res.StatusCode != http.StatusOK {
+		err = fmt.Errorf("retrieve encryption key failed for org [%v] with status: %v", org, res.Status)
+		return
+	}
+	defer res.Body.Close()
+	key64, err := ioutil.ReadAll(res.Body)
+	key, err = base64.StdEncoding.DecodeString(string(key64))
+	return
+}
+
+func (c *KmsCipherManager) getAesCipher(org string) (*cipher.AesCipher, error) {
+	// if exists
+	c.mutex.RLock()
+	if a := c.aes[org]; a != nil {
+		c.mutex.RUnlock()
+		return a, nil
+	}
+	c.mutex.RUnlock()
+	// if not exists
+	key, err := c.retrieveKey(org)
+	if err != nil {
+		log.Errorf("getAesCipher error for org [%v] when retrieveKey: %v", org, err)
+		return nil, err
+	}
+
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	c.key[org] = key
+	a, err := cipher.CreateAesCipher(key)
+	if err != nil {
+		log.Errorf("getAesCipher error for org [%v] when CreateAesCipher: %v", org, err)
+		return nil, err
+	}
+	c.aes[org] = a
+	return a, nil
+}
+
+// If input is encrypted, it decodes the input with base64,
+// and then decrypt it. Otherwise, original input is returned.
+// An encrypted input should be ciphertext prepended with algorithm. An unencrypted input can have any other format.
+// An example of encrypted input is "{AES/ECB/PKCS5Padding}2jX3V3dQ5xB9C9Zl9sqyo8pmkvVP10rkEVPVhmnLHw4=".
+func (c *KmsCipherManager) TryDecryptBase64(input string, org string) (output string, err error) {
+	if !IsEncrypted(input) {
+		output = input
+		return
+	}
+
+	text, mode, padding, err := GetCiphertext(input)
+	if err != nil {
+		log.Errorf("Get ciphertext of [%v] failed: [%v], considered as unencrypted!", input, err)
+		return
+	}
+	bytes, err := base64.StdEncoding.DecodeString(text)
+	if err != nil {
+		log.Errorf("Decode base64 of [%v] failed: [%v], considered as unencrypted!", text, err)
+		return
+	}
+	aes, err := c.getAesCipher(org)
+	if err != nil {
+		return
+	}
+	plaintext, err := aes.Decrypt(bytes, mode, padding)
+	if err != nil {
+		log.Errorf("Decrypt of [%v] failed: [%v], considered as unencrypted!", bytes, err)
+		return
+	}
+	output = string(plaintext)
+	return
+}
+
+// It encrypts the input, and then encodes the ciphertext with base64.
+// The returned string is the base64 encoding of the encrypted input, prepended with algorithm.
+// An example output is "{AES/ECB/PKCS5Padding}2jX3V3dQ5xB9C9Zl9sqyo8pmkvVP10rkEVPVhmnLHw4="
+func (c *KmsCipherManager) EncryptBase64(input string, org string, mode cipher.Mode, padding cipher.Padding) (output string, err error) {
+	aes, err := c.getAesCipher(org)
+	if err != nil {
+		return
+	}
+	ciphertext, err := aes.Encrypt([]byte(input), mode, padding)
+	if err != nil {
+		return
+	}
+	output = fmt.Sprintf("{%s/%s/%s}%s", EncryptAes, mode, padding, base64.StdEncoding.EncodeToString(ciphertext))
+	return
+}
+
+// TODO: make sure this regex has no false positive for all possible inputs
+func IsEncrypted(input string) (encrypted bool) {
+	return RegexpEncrypted.Match([]byte(input))
+}
+
+func GetCiphertext(input string) (ciphertext string, mode cipher.Mode, padding cipher.Padding, err error) {
+	l := strings.SplitN(input, "}", 2)
+	if len(l) != 2 {
+		err = fmt.Errorf("invalid input for GetCiphertext: %v", input)
+		return
+	}
+	ciphertext = l[1]
+	l = strings.Split(strings.TrimLeft(l[0], "{"), "/")
+	if len(l) != 3 {
+		err = fmt.Errorf("invalid input for GetCiphertext: %v", input)
+		return
+	}
+	// encryption algorithm
+	if strings.ToUpper(l[0]) != EncryptAes {
+		err = fmt.Errorf("unsupported algorithm for GetCiphertext: %v", l[0])
+		return
+	}
+	// mode
+	mode = cipher.Mode(strings.ToUpper(l[1]))
+	// padding
+	padding = cipher.Padding(strings.ToUpper(l[2]))
+	return
+}
diff --git a/common/interfaces.go b/common/interfaces.go
index 59249b5..fa49689 100644
--- a/common/interfaces.go
+++ b/common/interfaces.go
@@ -13,6 +13,8 @@
 // limitations under the License.
 package common
 
+import "github.com/apid/apid-core/cipher"
+
 type ApiManagerInterface interface {
 	InitAPI()
 }
@@ -22,3 +24,15 @@
 	GetDbVersion() string
 	GetKmsAttributes(tenantId string, entities ...string) map[string][]Attribute
 }
+
+type CipherManagerInterface interface {
+	// If input is encrypted, it decodes the input with base64,
+	// and then decrypt it. Otherwise, original input is returned.
+	// An encrypted input should be ciphertext prepended with algorithm. An unencrypted input can have any other format.
+	// An example input is "{AES/ECB/PKCS5Padding}2jX3V3dQ5xB9C9Zl9sqyo8pmkvVP10rkEVPVhmnLHw4=".
+	TryDecryptBase64(input string, org string) (output string, err error)
+	// It encrypts the input, and then encodes the ciphertext with base64.
+	// The returned string is the base64 encoding of the encrypted input, prepended with algorithm.
+	// An example output is "{AES/ECB/PKCS5Padding}2jX3V3dQ5xB9C9Zl9sqyo8pmkvVP10rkEVPVhmnLHw4="
+	EncryptBase64(input string, org string, mode cipher.Mode, padding cipher.Padding) (output string, err error)
+}