diff --git a/roundrobin/rebalancer_test.go b/roundrobin/rebalancer_test.go
index 46bde460..d0ee7c96 100644
--- a/roundrobin/rebalancer_test.go
+++ b/roundrobin/rebalancer_test.go
@@ -345,7 +345,7 @@ func (s *RBSuite) TestRebalancerStickySession(c *C) {
 	defer b.Close()
 	defer x.Close()
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	fwd, err := forward.New()
@@ -367,7 +367,7 @@ func (s *RBSuite) TestRebalancerStickySession(c *C) {
 	for i := 0; i < 10; i++ {
 		req, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
 		c.Assert(err, IsNil)
-		req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+		req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 
 		resp, err := http.DefaultClient.Do(req)
 		c.Assert(err, IsNil)
diff --git a/roundrobin/stickysessions.go b/roundrobin/stickysessions.go
index 3fabeb97..3fa8efb1 100644
--- a/roundrobin/stickysessions.go
+++ b/roundrobin/stickysessions.go
@@ -2,16 +2,62 @@
 package roundrobin
 
 import (
+	"crypto/md5"
+	"fmt"
 	"net/http"
 	"net/url"
 )
 
+var (
+	defaultSalt       = "vulcand/oxy"
+	defaultObfuscator = &MD5Obfucator{salt: defaultSalt, data: make(map[string]string)}
+)
+
+type Obfuscator interface {
+	Obfuscate(string) string
+	Normalize(string) string
+}
+
+// md5Table stores two mappings, one is plaintext to md5, the other is md5 to plaintext
+type MD5Obfucator struct {
+	salt string
+	data map[string]string
+}
+
+func MD5(text, salt string) string {
+	return fmt.Sprintf("%x", md5.Sum([]byte(text+salt)))
+}
+
+func (m *MD5Obfucator) Obfuscate(text string) string {
+	v, ok := m.data[text]
+	if ok {
+		return v
+	}
+
+	md5_value := MD5(text, m.salt)
+	m.data[md5_value] = text
+	m.data[text] = md5_value
+	return md5_value
+}
+
+func (m *MD5Obfucator) Normalize(md5_value string) string {
+	v, ok := m.data[md5_value]
+	if !ok {
+		return ""
+	}
+	return v
+}
+
 type StickySession struct {
 	cookieName string
+	obfuscator Obfuscator
 }
 
-func NewStickySession(cookieName string) *StickySession {
-	return &StickySession{cookieName}
+func NewStickySession(cookieName string, o Obfuscator) *StickySession {
+	if o == nil {
+		o = defaultObfuscator
+	}
+	return &StickySession{cookieName: cookieName, obfuscator: o}
 }
 
 // GetBackend returns the backend URL stored in the sticky cookie, iff the backend is still in the valid list of servers.
@@ -24,8 +70,8 @@ func (s *StickySession) GetBackend(req *http.Request, servers []*url.URL) (*url.
 	default:
 		return nil, false, err
 	}
-
-	serverURL, err := url.Parse(cookie.Value)
+	backend := s.obfuscator.Normalize(cookie.Value)
+	serverURL, err := url.Parse(backend)
 	if err != nil {
 		return nil, false, err
 	}
@@ -38,7 +84,8 @@ func (s *StickySession) GetBackend(req *http.Request, servers []*url.URL) (*url.
 }
 
 func (s *StickySession) StickBackend(backend *url.URL, w *http.ResponseWriter) {
-	cookie := &http.Cookie{Name: s.cookieName, Value: backend.String(), Path: "/"}
+	cookieValue := s.obfuscator.Obfuscate(backend.String())
+	cookie := &http.Cookie{Name: s.cookieName, Value: cookieValue, Path: "/"}
 	http.SetCookie(*w, cookie)
 }
 
diff --git a/roundrobin/stickysessions_test.go b/roundrobin/stickysessions_test.go
index 08f49391..96465de6 100644
--- a/roundrobin/stickysessions_test.go
+++ b/roundrobin/stickysessions_test.go
@@ -28,7 +28,7 @@ func (s *StickySessionSuite) TestBasic(c *C) {
 	fwd, err := forward.New()
 	c.Assert(err, IsNil)
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	lb, err := New(fwd, EnableStickySession(sticky))
@@ -47,7 +47,7 @@ func (s *StickySessionSuite) TestBasic(c *C) {
 	for i := 0; i < 10; i++ {
 		req, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
 		c.Assert(err, IsNil)
-		req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+		req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 
 		resp, err := client.Do(req)
 		c.Assert(err, IsNil)
@@ -70,7 +70,7 @@ func (s *StickySessionSuite) TestStickCookie(c *C) {
 	fwd, err := forward.New()
 	c.Assert(err, IsNil)
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	lb, err := New(fwd, EnableStickySession(sticky))
@@ -89,7 +89,7 @@ func (s *StickySessionSuite) TestStickCookie(c *C) {
 
 	cookie := resp.Cookies()[0]
 	c.Assert(cookie.Name, Equals, "test")
-	c.Assert(cookie.Value, Equals, a.URL)
+	c.Assert(cookie.Value, Equals, MD5(a.URL, defaultSalt))
 }
 
 func (s *StickySessionSuite) TestRemoveRespondingServer(c *C) {
@@ -102,7 +102,7 @@ func (s *StickySessionSuite) TestRemoveRespondingServer(c *C) {
 	fwd, err := forward.New()
 	c.Assert(err, IsNil)
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	lb, err := New(fwd, EnableStickySession(sticky))
@@ -121,7 +121,7 @@ func (s *StickySessionSuite) TestRemoveRespondingServer(c *C) {
 	for i := 0; i < 10; i++ {
 		req, errReq := http.NewRequest(http.MethodGet, proxy.URL, nil)
 		c.Assert(errReq, IsNil)
-		req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+		req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 
 		resp, errReq := client.Do(req)
 		c.Assert(errReq, IsNil)
@@ -139,12 +139,12 @@ func (s *StickySessionSuite) TestRemoveRespondingServer(c *C) {
 	// Now, use the organic cookie response in our next requests.
 	req, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
 	c.Assert(err, IsNil)
-	req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+	req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 	resp, err := client.Do(req)
 	c.Assert(err, IsNil)
 
 	c.Assert(resp.Cookies()[0].Name, Equals, "test")
-	c.Assert(resp.Cookies()[0].Value, Equals, b.URL)
+	c.Assert(resp.Cookies()[0].Value, Equals, MD5(b.URL, defaultSalt))
 
 	for i := 0; i < 10; i++ {
 		req, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
@@ -171,7 +171,7 @@ func (s *StickySessionSuite) TestRemoveAllServers(c *C) {
 	fwd, err := forward.New()
 	c.Assert(err, IsNil)
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	lb, err := New(fwd, EnableStickySession(sticky))
@@ -190,7 +190,7 @@ func (s *StickySessionSuite) TestRemoveAllServers(c *C) {
 	for i := 0; i < 10; i++ {
 		req, errReq := http.NewRequest(http.MethodGet, proxy.URL, nil)
 		c.Assert(errReq, IsNil)
-		req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+		req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 
 		resp, errReq := client.Do(req)
 		c.Assert(errReq, IsNil)
@@ -210,7 +210,7 @@ func (s *StickySessionSuite) TestRemoveAllServers(c *C) {
 	// Now, use the organic cookie response in our next requests.
 	req, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
 	c.Assert(err, IsNil)
-	req.AddCookie(&http.Cookie{Name: "test", Value: a.URL})
+	req.AddCookie(&http.Cookie{Name: "test", Value: MD5(a.URL, defaultSalt)})
 	resp, err := client.Do(req)
 	c.Assert(err, IsNil)
 	c.Assert(resp.StatusCode, Equals, http.StatusInternalServerError)
@@ -224,7 +224,7 @@ func (s *StickySessionSuite) TestBadCookieVal(c *C) {
 	fwd, err := forward.New()
 	c.Assert(err, IsNil)
 
-	sticky := NewStickySession("test")
+	sticky := NewStickySession("test", nil)
 	c.Assert(sticky, NotNil)
 
 	lb, err := New(fwd, EnableStickySession(sticky))