diff --git a/api/v1/heimdall.pb.go b/api/v1/heimdall.pb.go
index e22ca8e..b1c32a0 100644
--- a/api/v1/heimdall.pb.go
+++ b/api/v1/heimdall.pb.go
@@ -81,6 +81,7 @@ func (m *Master) GetRedisURL() string {
 
 type ConnectRequest struct {
 	ID                   string   `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
+	ClusterKey           string   `protobuf:"bytes,2,opt,name=cluster_key,json=clusterKey,proto3" json:"cluster_key,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -117,6 +118,13 @@ func (m *ConnectRequest) GetID() string {
 	return ""
 }
 
+func (m *ConnectRequest) GetClusterKey() string {
+	if m != nil {
+		return m.ClusterKey
+	}
+	return ""
+}
+
 type ConnectResponse struct {
 	Master               *Master  `protobuf:"bytes,1,opt,name=master,proto3" json:"master,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
@@ -283,30 +291,31 @@ func init() {
 }
 
 var fileDescriptor_b6184fc395da86b1 = []byte{
-	// 354 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x94, 0x92, 0xc1, 0x6b, 0xc2, 0x30,
-	0x14, 0xc6, 0xb1, 0xba, 0x4e, 0x5f, 0x9d, 0x42, 0x18, 0xa3, 0x78, 0xd1, 0xf5, 0x32, 0x85, 0x91,
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-	0x50, 0xb6, 0x8c, 0x82, 0x24, 0x71, 0x83, 0x8c, 0xb9, 0x6b, 0x6f, 0x57, 0xe3, 0x4c, 0xf0, 0x9c,
-	0xa3, 0x4b, 0xc6, 0xf1, 0x3e, 0x81, 0x77, 0x8a, 0x20, 0x63, 0x78, 0xed, 0x75, 0xce, 0x63, 0x1e,
-	0x73, 0xa5, 0x76, 0x8b, 0x57, 0x09, 0x3a, 0x3f, 0x60, 0xbe, 0x06, 0x32, 0xa7, 0x02, 0x5d, 0x80,
-	0xc1, 0x22, 0xbb, 0xd2, 0xab, 0xf4, 0x1b, 0x23, 0x73, 0xbb, 0xe9, 0x1a, 0xcf, 0x0f, 0xc4, 0x60,
-	0x11, 0xf2, 0xa1, 0x19, 0x8b, 0x2c, 0x9c, 0x05, 0x51, 0x24, 0xa8, 0x94, 0xb6, 0xa1, 0x14, 0xed,
-	0xed, 0xa6, 0x6b, 0x3d, 0x92, 0xb7, 0xf1, 0xb0, 0x6c, 0x13, 0xab, 0x10, 0xe9, 0x02, 0x0d, 0xa0,
-	0x21, 0x68, 0xc4, 0xe4, 0x6c, 0x25, 0x12, 0xbb, 0xaa, 0x80, 0xe6, 0x76, 0xd3, 0xad, 0x93, 0xa2,
-	0x39, 0x25, 0x2f, 0xa4, 0xae, 0xbe, 0xa7, 0x22, 0x71, 0xfa, 0xd0, 0x1a, 0xf3, 0x34, 0xa5, 0x61,
-	0x4e, 0xe8, 0xd7, 0x8a, 0xca, 0xfc, 0x90, 0x11, 0xe7, 0x1d, 0xda, 0x3b, 0xa5, 0xcc, 0x78, 0x2a,
-	0x29, 0x1a, 0x82, 0xb9, 0x54, 0xee, 0x95, 0xdc, 0xf2, 0x07, 0xf8, 0xcf, 0x3d, 0xe0, 0x32, 0x2e,
-	0xd1, 0xa0, 0xe3, 0x43, 0x6d, 0xc2, 0x23, 0x7a, 0x30, 0x3e, 0x82, 0x5a, 0x91, 0xbc, 0x8c, 0x4d,
-	0xd4, 0xdb, 0x69, 0x41, 0xb3, 0x60, 0xa4, 0x76, 0xec, 0x4c, 0xe0, 0x4c, 0xd7, 0xda, 0xd7, 0x3d,
-	0x9c, 0xa4, 0x45, 0xc3, 0xae, 0xf4, 0xaa, 0x7d, 0xcb, 0xbf, 0x3a, 0xc2, 0x56, 0x31, 0x80, 0x94,
-	0x94, 0xff, 0x0d, 0xf5, 0x27, 0xfd, 0x8d, 0x32, 0x38, 0xd5, 0xa9, 0x91, 0x77, 0xc4, 0x98, 0xfd,
-	0x5d, 0x76, 0xfc, 0xff, 0x20, 0xa5, 0xf9, 0x11, 0xfe, 0xb8, 0x3e, 0xfa, 0x0e, 0xef, 0xd6, 0xde,
-	0xdc, 0x54, 0x97, 0x74, 0xf3, 0x1b, 0x00, 0x00, 0xff, 0xff, 0x2b, 0x3d, 0x45, 0x9b, 0xbe, 0x02,
-	0x00, 0x00,
+	// 375 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x94, 0x92, 0xc1, 0xab, 0xda, 0x40,
+	0x10, 0xc6, 0x31, 0xda, 0x54, 0x27, 0x56, 0x61, 0x29, 0x25, 0x78, 0x89, 0xcd, 0xa5, 0x0a, 0x65,
+	0x43, 0xd2, 0x4b, 0xa1, 0xf4, 0xa0, 0x16, 0x5a, 0x69, 0x2b, 0x65, 0xa9, 0x97, 0x5e, 0x24, 0x26,
+	0x4b, 0xdc, 0x36, 0x66, 0xd3, 0xdd, 0x44, 0x10, 0x0a, 0xfd, 0x4f, 0x3d, 0xf8, 0x97, 0x3c, 0x76,
+	0xb3, 0x08, 0x1e, 0xe4, 0xf9, 0x6e, 0x3b, 0xb3, 0xf3, 0x7d, 0xfc, 0xe6, 0x63, 0xe0, 0x7d, 0xc6,
+	0xaa, 0x5d, 0xbd, 0xc5, 0x09, 0xdf, 0x07, 0xb2, 0xa2, 0x79, 0x1e, 0x8b, 0x52, 0xf0, 0xdf, 0x34,
+	0xa9, 0x82, 0x1d, 0x65, 0xfb, 0x34, 0xce, 0xf3, 0x20, 0x2e, 0x59, 0x70, 0x08, 0x2f, 0x35, 0x2e,
+	0x05, 0xaf, 0x38, 0x7a, 0xcd, 0x38, 0xbe, 0x56, 0xe0, 0xcb, 0x44, 0x5c, 0x32, 0x7c, 0x08, 0x47,
+	0x2f, 0x33, 0x9e, 0x71, 0x3d, 0x1d, 0xa8, 0x57, 0x23, 0xf4, 0xff, 0x83, 0xfd, 0x3d, 0x96, 0x15,
+	0x15, 0xe8, 0x15, 0x58, 0x2c, 0x75, 0x5b, 0xe3, 0xd6, 0xa4, 0x37, 0xb7, 0xcf, 0x27, 0xcf, 0x5a,
+	0x7e, 0x22, 0x16, 0x4b, 0x51, 0x04, 0xfd, 0x4c, 0x94, 0xc9, 0x26, 0x4e, 0x53, 0x41, 0xa5, 0x74,
+	0x2d, 0x3d, 0x31, 0x3c, 0x9f, 0x3c, 0xe7, 0x33, 0xf9, 0xb1, 0x98, 0x35, 0x6d, 0xe2, 0xa8, 0x21,
+	0x53, 0xa0, 0x29, 0xf4, 0x04, 0x4d, 0x99, 0xdc, 0xd4, 0x22, 0x77, 0xdb, 0x5a, 0xd0, 0x3f, 0x9f,
+	0xbc, 0x2e, 0x51, 0xcd, 0x35, 0xf9, 0x46, 0xba, 0xfa, 0x7b, 0x2d, 0x72, 0x7f, 0x09, 0x83, 0x05,
+	0x2f, 0x0a, 0x9a, 0x54, 0x84, 0xfe, 0xad, 0xa9, 0xac, 0x6e, 0x82, 0x78, 0xe0, 0x24, 0x79, 0xad,
+	0x58, 0x37, 0x7f, 0xe8, 0xb1, 0xe1, 0x20, 0x60, 0x5a, 0x5f, 0xe9, 0xd1, 0xff, 0x09, 0xc3, 0x8b,
+	0x95, 0x2c, 0x79, 0x21, 0x29, 0x9a, 0x81, 0xbd, 0xd7, 0xeb, 0x69, 0x3f, 0x27, 0x9a, 0xe2, 0x47,
+	0x83, 0xc2, 0x4d, 0x1e, 0xc4, 0x08, 0xfd, 0x08, 0x3a, 0x2b, 0x9e, 0xd2, 0x9b, 0x58, 0x08, 0x3a,
+	0x2a, 0x1a, 0xc3, 0xa3, 0xdf, 0xfe, 0x00, 0xfa, 0x4a, 0x23, 0xcd, 0x4a, 0xfe, 0x0a, 0x5e, 0x98,
+	0xda, 0x70, 0x7d, 0x84, 0x67, 0x85, 0x6a, 0xb8, 0xad, 0x71, 0x7b, 0xe2, 0x44, 0x6f, 0xee, 0xc0,
+	0x52, 0x06, 0xa4, 0x51, 0x45, 0xff, 0xa0, 0xfb, 0xc5, 0x7c, 0xa3, 0x12, 0x9e, 0x9b, 0xad, 0x51,
+	0x78, 0x87, 0xcd, 0x75, 0xd8, 0xa3, 0xe8, 0x29, 0x92, 0x06, 0x7e, 0x8e, 0x7f, 0xbd, 0xbd, 0xfb,
+	0x50, 0x3f, 0x1c, 0xc2, 0xad, 0xad, 0x4f, 0xed, 0xdd, 0x43, 0x00, 0x00, 0x00, 0xff, 0xff, 0x57,
+	0x3c, 0x78, 0x51, 0xdf, 0x02, 0x00, 0x00,
 }
 
 // Reference imports to suppress errors if they are not otherwise used.
diff --git a/api/v1/heimdall.proto b/api/v1/heimdall.proto
index c2fd728..d2be522 100644
--- a/api/v1/heimdall.proto
+++ b/api/v1/heimdall.proto
@@ -22,6 +22,7 @@ message Master {
 
 message ConnectRequest {
         string id = 1 [(gogoproto.customname) = "ID"];
+        string cluster_key = 2;
 }
 
 message ConnectResponse {
diff --git a/client/connect.go b/client/connect.go
index 72d5904..6ecd53d 100644
--- a/client/connect.go
+++ b/client/connect.go
@@ -28,10 +28,11 @@ import (
 )
 
 // Connect attempts to connect to the peer and returns the master info
-func (c *Client) Connect() (*v1.Master, error) {
+func (c *Client) Connect(key string) (*v1.Master, error) {
 	ctx := context.Background()
 	resp, err := c.heimdallClient.Connect(ctx, &v1.ConnectRequest{
-		ID: c.id,
+		ID:         c.id,
+		ClusterKey: key,
 	})
 	if err != nil {
 		return nil, err
diff --git a/cmd/heimdall/main.go b/cmd/heimdall/main.go
index ab13255..8355f31 100644
--- a/cmd/heimdall/main.go
+++ b/cmd/heimdall/main.go
@@ -25,6 +25,7 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/google/uuid"
 	log "github.com/sirupsen/logrus"
 	"github.com/stellarproject/heimdall"
 	"github.com/stellarproject/heimdall/version"
@@ -76,6 +77,12 @@ func main() {
 			Usage:  "grpc address to join a peer",
 			EnvVar: "HEIMDALL_PEER",
 		},
+		cli.StringFlag{
+			Name:   "cluster-key",
+			Usage:  "preshared key for cluster peer joins",
+			Value:  generateKey(),
+			EnvVar: "HEIMDALL_CLUSTER_KEY",
+		},
 	}
 	app.Before = func(c *cli.Context) error {
 		if c.Bool("debug") {
@@ -90,3 +97,7 @@ func main() {
 		log.Fatal(err)
 	}
 }
+
+func generateKey() string {
+	return uuid.New().String()
+}
diff --git a/cmd/heimdall/run.go b/cmd/heimdall/run.go
index 8027beb..a491a1f 100644
--- a/cmd/heimdall/run.go
+++ b/cmd/heimdall/run.go
@@ -44,6 +44,7 @@ func runServer(cx *cli.Context) error {
 		ID:                cx.String("id"),
 		GRPCAddress:       cx.String("addr"),
 		GRPCPeerAddress:   cx.String("peer"),
+		ClusterKey:        cx.String("cluster-key"),
 		RedisURL:          cx.String("redis-url"),
 		AdvertiseRedisURL: cx.String("advertise-redis-url"),
 	}
diff --git a/config.go b/config.go
index 88d50d8..cfe2a06 100644
--- a/config.go
+++ b/config.go
@@ -29,6 +29,8 @@ type Config struct {
 	GRPCAddress string
 	// GRPCPeerAddress is the peer address to join
 	GRPCPeerAddress string
+	// ClusterKey is a preshared key for cluster peers
+	ClusterKey string
 	// RedisURL is the uri to the redis backend
 	RedisURL string
 	// AdvertiseRedisURL is the uri to the public redis backend
diff --git a/server/connect.go b/server/connect.go
index 4e40202..46489f8 100644
--- a/server/connect.go
+++ b/server/connect.go
@@ -23,6 +23,7 @@ package server
 
 import (
 	"context"
+	"errors"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/gomodule/redigo/redis"
@@ -30,9 +31,21 @@ import (
 	v1 "github.com/stellarproject/heimdall/api/v1"
 )
 
+var (
+	// ErrInvalidAuth is returned when an invalid cluster key is specified upon connect
+	ErrInvalidAuth = errors.New("invalid cluster key specified")
+)
+
 // Connect is called when a peer wants to connect to the node
 func (s *Server) Connect(ctx context.Context, req *v1.ConnectRequest) (*v1.ConnectResponse, error) {
 	logrus.Debugf("connect request from %s", req.ID)
+	key, err := s.getClusterKey(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if req.ClusterKey != key {
+		return nil, ErrInvalidAuth
+	}
 	data, err := redis.Bytes(s.local(ctx, "GET", masterKey))
 	if err != nil {
 		return nil, err
diff --git a/server/node.go b/server/node.go
index fb41a5d..2e82ba9 100644
--- a/server/node.go
+++ b/server/node.go
@@ -60,7 +60,7 @@ func (s *Server) configureNode() error {
 				logrus.Warn(err)
 				continue
 			}
-			m, err := c.Connect()
+			m, err := c.Connect(s.cfg.ClusterKey)
 			if err != nil {
 				c.Close()
 				logrus.Warn(err)
@@ -149,13 +149,17 @@ func (s *Server) replicaMonitor() {
 func (s *Server) masterHeartbeat() {
 	logrus.Debugf("starting master heartbeat: ttl=%s", heartbeatInterval)
 	// initial update
-	if err := s.updateMasterInfo(); err != nil {
+	ctx, cancel := context.WithTimeout(context.Background(), heartbeatInterval)
+	defer cancel()
+
+	logrus.Infof("cluster master key=%s", s.cfg.ClusterKey)
+	if err := s.updateMasterInfo(ctx); err != nil {
 		logrus.Error(err)
 	}
 
 	t := time.NewTicker(heartbeatInterval)
 	for range t.C {
-		if err := s.updateMasterInfo(); err != nil {
+		if err := s.updateMasterInfo(ctx); err != nil {
 			logrus.Error(err)
 			continue
 		}
@@ -193,8 +197,11 @@ func (s *Server) joinMaster(m *v1.Master) error {
 	return nil
 }
 
-func (s *Server) updateMasterInfo() error {
+func (s *Server) updateMasterInfo(ctx context.Context) error {
 	// update master info
+	if _, err := s.master(ctx, "SET", clusterKey, s.cfg.ClusterKey); err != nil {
+		return err
+	}
 	m := &v1.Master{
 		ID:          s.cfg.ID,
 		GRPCAddress: s.cfg.GRPCAddress,
@@ -205,27 +212,28 @@ func (s *Server) updateMasterInfo() error {
 		return errors.Wrap(err, "error marshalling master info")
 	}
 
-	if _, err := s.master(context.Background(), "SET", masterKey, data); err != nil {
+	if _, err := s.master(ctx, "SET", masterKey, data); err != nil {
 		return errors.Wrap(err, "error setting master info")
 	}
 
-	if _, err := s.master(context.Background(), "EXPIRE", masterKey, int(heartbeatInterval.Seconds())); err != nil {
+	if _, err := s.master(ctx, "EXPIRE", masterKey, int(heartbeatInterval.Seconds())); err != nil {
 		return errors.Wrap(err, "error setting expire for master info")
 	}
 	return nil
 }
 
 func (s *Server) nodeHeartbeat() {
-	logrus.Debugf("starting node heartbeat: ttl=%s", heartbeatInterval)
-	t := time.NewTicker(heartbeatInterval)
+	logrus.Debugf("starting node heartbeat: ttl=%s", nodeHeartbeatInterval)
+	ctx := context.Background()
+	t := time.NewTicker(nodeHeartbeatInterval)
 	key := fmt.Sprintf("%s:%s", nodesKey, s.cfg.ID)
 	for range t.C {
-		if _, err := s.master(context.Background(), "SET", key, s.cfg.GRPCAddress); err != nil {
+		if _, err := s.master(ctx, "SET", key, s.cfg.GRPCAddress); err != nil {
 			logrus.Error(err)
 			continue
 		}
 
-		if _, err := s.master(context.Background(), "EXPIRE", key, nodeHeartbeatExpiry); err != nil {
+		if _, err := s.master(ctx, "EXPIRE", key, nodeHeartbeatExpiry); err != nil {
 			logrus.Error(err)
 			continue
 		}
diff --git a/server/server.go b/server/server.go
index aeea7b8..4af4023 100644
--- a/server/server.go
+++ b/server/server.go
@@ -40,14 +40,16 @@ import (
 
 const (
 	masterKey   = "heimdall:master"
+	clusterKey  = "heimdall:key"
 	nodesKey    = "heimdall:nodes"
 	nodeJoinKey = "heimdall:join"
 )
 
 var (
-	empty               = &ptypes.Empty{}
-	heartbeatInterval   = time.Second * 15
-	nodeHeartbeatExpiry = 86400
+	empty                 = &ptypes.Empty{}
+	heartbeatInterval     = time.Second * 5
+	nodeHeartbeatInterval = time.Second * 60
+	nodeHeartbeatExpiry   = 86400
 )
 
 type Server struct {
@@ -97,7 +99,7 @@ func (s *Server) Run() error {
 		}
 		defer c.Close()
 
-		master, err := c.Connect()
+		master, err := c.Connect(s.cfg.ClusterKey)
 		if err != nil {
 			return err
 		}
@@ -163,6 +165,10 @@ func (s *Server) getClient(addr string) (*client.Client, error) {
 	return client.NewClient(s.cfg.ID, addr)
 }
 
+func (s *Server) getClusterKey(ctx context.Context) (string, error) {
+	return redis.String(s.local(ctx, "GET", clusterKey))
+}
+
 func (s *Server) local(ctx context.Context, cmd string, args ...interface{}) (interface{}, error) {
 	return s.do(ctx, s.rpool, cmd, args...)
 }