diff --git a/dfssc/sign/server.go b/dfssc/sign/server.go
index 4c5ba6ec3c69dda1cbe5987b3a3b1f0d50174881..92c4c427b979b129c06f63f8b6c79539d94906ba 100644
--- a/dfssc/sign/server.go
+++ b/dfssc/sign/server.go
@@ -1,13 +1,10 @@
 package sign
 
 import (
-	"fmt"
-
 	"dfss"
 	cAPI "dfss/dfssc/api"
 	pAPI "dfss/dfssp/api"
 	"dfss/net"
-
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 )
@@ -34,7 +31,6 @@ func (s *clientServer) TreatSignature(ctx context.Context, in *cAPI.Signature) (
 //
 // Handle incoming Discover messages
 func (s *clientServer) Discover(ctx context.Context, in *cAPI.Hello) (*cAPI.Hello, error) {
-	fmt.Println("Recieved:", in.Version)
 	return &cAPI.Hello{Version: dfss.Version}, nil
 }
 
diff --git a/dfssc/sign/starter.go b/dfssc/sign/starter.go
index 8f33c128a9ab91b77800be0d23a563733b8d07e7..b428ba3a67acd3e0d52441efc5ac98c29da7e78e 100644
--- a/dfssc/sign/starter.go
+++ b/dfssc/sign/starter.go
@@ -5,6 +5,7 @@ import (
 	"crypto/x509"
 	"errors"
 	"fmt"
+	"log"
 	"strconv"
 	"time"
 
@@ -28,6 +29,8 @@ type SignatureManager struct {
 	cServer   *grpc.Server
 	cert, ca  *x509.Certificate
 	key       *rsa.PrivateKey
+	sequence  []uint32
+	uuid      string
 }
 
 // NewSignatureManager populates a SignatureManager and connects to the platform.
@@ -44,7 +47,7 @@ func NewSignatureManager(fileCA, fileCert, fileKey, addrPort, passphrase string,
 	}
 
 	m.cServer = m.GetServer()
-	go func() { _ = net.Listen("0.0.0.0:"+strconv.Itoa(port), m.cServer) }()
+	go func() { log.Fatalln(net.Listen("0.0.0.0:"+strconv.Itoa(port), m.cServer)) }()
 
 	conn, err := net.Connect(m.auth.AddrPort, m.cert, m.key, m.ca)
 	if err != nil {
@@ -55,7 +58,9 @@ func NewSignatureManager(fileCA, fileCert, fileKey, addrPort, passphrase string,
 
 	m.peers = make(map[string]*cAPI.ClientClient)
 	for _, u := range c.Signers {
-		m.peers[u.Email] = nil
+		if u.Email != m.cert.Subject.CommonName {
+			m.peers[u.Email] = nil
+		}
 	}
 
 	return m, nil
@@ -82,7 +87,7 @@ func (m *SignatureManager) ConnectToPeers() error {
 		}
 		ready, err := m.addPeer(userConnected.User)
 		if err != nil {
-			return err
+			continue // Unable to connect to this user, ignore it for the moment
 		}
 		if ready {
 			break
@@ -98,9 +103,12 @@ func (m *SignatureManager) addPeer(user *pAPI.User) (ready bool, err error) {
 		err = errors.New("unexpected user format")
 		return
 	}
+	if _, ok := m.peers[user.Email]; !ok {
+		return // Ignore if unknown
+	}
 
 	addrPort := user.Ip + ":" + strconv.Itoa(int(user.Port))
-	fmt.Println("Trying to connect with", user.Email, "/", addrPort)
+	fmt.Println("- Trying to connect with", user.Email, "/", addrPort)
 
 	conn, err := net.Connect(addrPort, m.cert, m.key, m.ca)
 	if err != nil {
@@ -110,12 +118,17 @@ func (m *SignatureManager) addPeer(user *pAPI.User) (ready bool, err error) {
 	// Sending Hello message
 	client := cAPI.NewClientClient(conn)
 	m.peers[user.Email] = &client
-	msg, err := client.Discover(context.Background(), &cAPI.Hello{Version: dfss.Version})
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	msg, err := client.Discover(ctx, &cAPI.Hello{Version: dfss.Version})
 	if err != nil {
 		return false, err
 	}
+
 	// Printing answer: application version
-	fmt.Println("Recieved:", msg.Version)
+	// TODO check certificate
+	fmt.Println("  Successfully connected!", "[", msg.Version, "]")
 
 	// Check if we have any other peer to connect to
 	for _, u := range m.peers {
@@ -129,7 +142,7 @@ func (m *SignatureManager) addPeer(user *pAPI.User) (ready bool, err error) {
 
 // SendReadySign sends the READY signal to the platform, and wait (potentially a long time) for START signal.
 func (m *SignatureManager) SendReadySign() (signatureUUID string, err error) {
-	ctx, cancel := context.WithTimeout(context.Background(), 10 * time.Minute)
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
 	defer cancel()
 	launch, err := m.platform.ReadySign(ctx, &pAPI.ReadySignRequest{
 		ContractUuid: m.contract.UUID,
@@ -144,6 +157,21 @@ func (m *SignatureManager) SendReadySign() (signatureUUID string, err error) {
 		return
 	}
 
-	signatureUUID = launch.SignatureUuid
+	// Check signers from platform data
+	if len(m.contract.Signers) != len(launch.KeyHash) {
+		err = errors.New("Corrupted DFSS file: bad number of signers, unable to sign safely")
+		return
+	}
+
+	for i, s := range m.contract.Signers {
+		if s.Hash != fmt.Sprintf("%x", launch.KeyHash[i]) {
+			err = errors.New("Corrupted DFSS file: signer " + s.Email + " has an invalid hash, unable to sign safely")
+			return
+		}
+	}
+
+	m.sequence = launch.Sequence
+	m.uuid = launch.SignatureUuid
+	signatureUUID = m.uuid
 	return
 }
diff --git a/dfssp/api/platform.pb.go b/dfssp/api/platform.pb.go
index b9e4552f946425e81c44ea33a5ea5cf424ee2acc..eed627b0e57b3145525e986fbd06033f31f89981 100644
--- a/dfssp/api/platform.pb.go
+++ b/dfssp/api/platform.pb.go
@@ -211,6 +211,7 @@ type LaunchSignature struct {
 	ErrorCode     *ErrorCode `protobuf:"bytes,1,opt,name=errorCode" json:"errorCode,omitempty"`
 	SignatureUuid string     `protobuf:"bytes,2,opt,name=signatureUuid" json:"signatureUuid,omitempty"`
 	KeyHash       [][]byte   `protobuf:"bytes,3,rep,name=keyHash,proto3" json:"keyHash,omitempty"`
+	Sequence      []uint32   `protobuf:"varint,4,rep,name=sequence" json:"sequence,omitempty"`
 }
 
 func (m *LaunchSignature) Reset()                    { *m = LaunchSignature{} }
@@ -471,44 +472,45 @@ var _Platform_serviceDesc = grpc.ServiceDesc{
 }
 
 var fileDescriptor0 = []byte{
-	// 621 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x94, 0x54, 0x5d, 0x6f, 0xd3, 0x30,
-	0x14, 0x6d, 0xda, 0xec, 0xa3, 0x77, 0x6b, 0x17, 0xb9, 0x03, 0x95, 0x4a, 0x43, 0x93, 0x85, 0x04,
-	0x42, 0xa8, 0x9d, 0x8a, 0x84, 0x04, 0x6f, 0x59, 0xa9, 0xb6, 0x21, 0x54, 0x4d, 0xee, 0x0a, 0x12,
-	0x6f, 0x21, 0xf1, 0xd6, 0x68, 0xcd, 0x07, 0xb6, 0x23, 0xb4, 0x27, 0xf8, 0x25, 0xfc, 0x2d, 0x7e,
-	0x0e, 0xd8, 0x4e, 0x9c, 0x26, 0xa3, 0x42, 0xda, 0x1e, 0x32, 0xdf, 0xeb, 0xeb, 0x73, 0x7c, 0xce,
-	0xbd, 0x2e, 0x1c, 0x05, 0xd7, 0x9c, 0x8f, 0xd4, 0x27, 0x1d, 0x79, 0x69, 0x38, 0x4a, 0x57, 0x9e,
-	0xb8, 0x4e, 0x58, 0x34, 0x4c, 0x59, 0x22, 0x12, 0xd4, 0x92, 0x39, 0xec, 0xc2, 0x01, 0xa1, 0x37,
-	0x21, 0x17, 0x94, 0x11, 0xfa, 0x2d, 0xa3, 0x5c, 0xa0, 0x43, 0xd8, 0xa2, 0x91, 0x17, 0xae, 0xfa,
-	0xd6, 0xb1, 0xf5, 0xa2, 0x4d, 0xf2, 0x00, 0xf5, 0x61, 0x87, 0xe5, 0x05, 0xfd, 0xa6, 0xce, 0x9b,
-	0x10, 0xff, 0xb2, 0xa0, 0x3d, 0x65, 0x2c, 0x61, 0x93, 0x24, 0xa0, 0xe8, 0x39, 0xd8, 0xbe, 0xfc,
-	0xaf, 0x0f, 0x77, 0xc7, 0xbd, 0xa1, 0x24, 0x19, 0x96, 0xbb, 0x43, 0xf5, 0x21, 0xba, 0x40, 0x01,
-	0x46, 0x94, 0x73, 0xef, 0x86, 0x1a, 0xc0, 0x22, 0xc4, 0x33, 0xb0, 0x35, 0xd4, 0x1e, 0xec, 0xcc,
-	0x17, 0x93, 0xc9, 0x74, 0x3e, 0x77, 0x1a, 0x08, 0x60, 0xfb, 0x62, 0xf6, 0xc9, 0x25, 0x67, 0x8e,
-	0xa5, 0x36, 0x4e, 0xdd, 0xf7, 0xee, 0xe2, 0xea, 0xdc, 0x69, 0xaa, 0xe0, 0xb3, 0x4b, 0x66, 0x17,
-	0xb3, 0x33, 0xa7, 0x85, 0x7a, 0xaa, 0xea, 0x6a, 0x4a, 0x88, 0xf3, 0xc7, 0xfc, 0x59, 0xf8, 0x2d,
-	0xec, 0xb9, 0x99, 0x58, 0xfe, 0x5f, 0x9f, 0xcc, 0x8a, 0xe4, 0x96, 0xc6, 0xc5, 0x65, 0xf2, 0x00,
-	0x9f, 0x40, 0xd7, 0xd8, 0x43, 0x83, 0x05, 0xa7, 0x0c, 0x3d, 0x05, 0xf0, 0x57, 0x21, 0x8d, 0xc5,
-	0x84, 0x32, 0x51, 0x40, 0x54, 0x32, 0x78, 0x07, 0xb6, 0xa6, 0x51, 0x2a, 0xee, 0xf0, 0x77, 0xe8,
-	0x5d, 0x26, 0x5c, 0x4c, 0x92, 0x58, 0x30, 0xcf, 0x17, 0x86, 0x1d, 0x81, 0xbd, 0xf4, 0xf8, 0x52,
-	0x9f, 0xdc, 0x27, 0x7a, 0x8d, 0x06, 0xb0, 0x7b, 0x1d, 0xae, 0x68, 0xec, 0x45, 0xc6, 0x8b, 0x32,
-	0x46, 0x8f, 0x61, 0x9b, 0x87, 0x37, 0x31, 0x65, 0xfd, 0xd6, 0x71, 0x4b, 0xee, 0x14, 0x91, 0xb2,
-	0xcf, 0x4f, 0xa2, 0x48, 0xd2, 0xf6, 0xed, 0xdc, 0xbe, 0x22, 0x94, 0xf6, 0x1d, 0x7e, 0x48, 0xc2,
-	0x78, 0x2e, 0xeb, 0x3c, 0x91, 0x31, 0x6a, 0x98, 0x31, 0xec, 0xfb, 0xc5, 0x65, 0x16, 0x59, 0x18,
-	0x14, 0x77, 0xaf, 0xe5, 0xd4, 0xed, 0xd2, 0x84, 0xe5, 0x2d, 0xee, 0x10, 0xbd, 0xc6, 0x3f, 0x2d,
-	0xe8, 0x28, 0xe9, 0x52, 0x49, 0x4c, 0x7d, 0x41, 0x03, 0xf4, 0x0a, 0xda, 0xd4, 0xb4, 0x54, 0xc3,
-	0xec, 0x8d, 0xbb, 0xf5, 0x46, 0x93, 0x75, 0xc1, 0x3f, 0xbc, 0xcd, 0x0d, 0xbc, 0x47, 0x60, 0x67,
-	0x5c, 0x6b, 0x54, 0x60, 0x6d, 0x0d, 0xa6, 0x38, 0x89, 0x4e, 0xe3, 0x2f, 0x60, 0x6b, 0xf3, 0xa5,
-	0xe8, 0x5b, 0x7a, 0x77, 0xbe, 0xf6, 0xcf, 0x84, 0xeb, 0xa6, 0x36, 0xab, 0x4d, 0xed, 0x42, 0x33,
-	0x4c, 0x35, 0x68, 0x9b, 0xc8, 0x55, 0x29, 0xcf, 0xae, 0xc8, 0x7b, 0x03, 0x0e, 0xa1, 0x5e, 0x70,
-	0xa7, 0xfc, 0x7a, 0x80, 0x55, 0xf8, 0x07, 0x1c, 0x7c, 0xf4, 0xb2, 0xd8, 0x5f, 0x96, 0x46, 0x3f,
-	0xd0, 0x97, 0x67, 0xd0, 0xe1, 0xe6, 0x68, 0xc5, 0x98, 0x7a, 0xb2, 0x2a, 0x59, 0x0d, 0xc0, 0x5a,
-	0xf2, 0xf8, 0x77, 0x13, 0x76, 0x2f, 0x8b, 0x27, 0x8d, 0xc6, 0xb0, 0x6b, 0x06, 0x15, 0x1d, 0x6a,
-	0xce, 0x7b, 0xcf, 0x7a, 0x70, 0xef, 0x26, 0xb8, 0x81, 0x46, 0x60, 0xab, 0x77, 0x81, 0x1c, 0xbd,
-	0x53, 0x79, 0x22, 0x83, 0x5e, 0x0d, 0x21, 0x9f, 0x7c, 0x79, 0xe0, 0x25, 0xc0, 0x22, 0x66, 0x86,
-	0x06, 0x72, 0x40, 0x35, 0xec, 0x1b, 0xc0, 0xdf, 0xc1, 0x7e, 0x75, 0xfc, 0x51, 0x5f, 0x57, 0x6c,
-	0x78, 0x11, 0x1b, 0xce, 0x9e, 0x42, 0xa7, 0x36, 0xc1, 0xe8, 0x89, 0x2e, 0xd9, 0x34, 0xd5, 0x03,
-	0x54, 0xce, 0x4a, 0x39, 0x9f, 0xb8, 0x71, 0x62, 0x49, 0xfe, 0x76, 0xd9, 0x56, 0xf4, 0xa8, 0xd0,
-	0x53, 0x6f, 0xf3, 0x20, 0x37, 0xea, 0x5e, 0x17, 0x71, 0xe3, 0xeb, 0xb6, 0xfe, 0x81, 0x7c, 0xfd,
-	0x37, 0x00, 0x00, 0xff, 0xff, 0xe1, 0xe6, 0x41, 0xec, 0x41, 0x05, 0x00, 0x00,
+	// 636 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x94, 0x54, 0x6d, 0x6b, 0x13, 0x41,
+	0x10, 0xce, 0x25, 0xd7, 0x97, 0x4c, 0x9b, 0xf4, 0xd8, 0x54, 0x89, 0x81, 0x4a, 0x59, 0x04, 0x45,
+	0x24, 0x29, 0x11, 0x04, 0xfd, 0x76, 0x8d, 0xa1, 0xad, 0x48, 0x28, 0x9b, 0x46, 0xc1, 0x6f, 0xe7,
+	0xdd, 0xb6, 0x39, 0x9a, 0x7b, 0x71, 0x77, 0x0f, 0xe9, 0x37, 0xff, 0x87, 0xe0, 0xdf, 0xf2, 0xe7,
+	0xe8, 0xee, 0xde, 0xed, 0xf5, 0x2e, 0x06, 0xa1, 0xfd, 0x70, 0xdd, 0x99, 0x9d, 0x7d, 0x66, 0x9e,
+	0x67, 0x66, 0x02, 0x47, 0xc1, 0x35, 0xe7, 0x23, 0xf5, 0x49, 0x47, 0x5e, 0x1a, 0x8e, 0xd2, 0x95,
+	0x27, 0xae, 0x13, 0x16, 0x0d, 0x53, 0x96, 0x88, 0x04, 0xb5, 0xa4, 0x0f, 0xbb, 0x70, 0x40, 0xe8,
+	0x4d, 0xc8, 0x05, 0x65, 0x84, 0x7e, 0xcb, 0x28, 0x17, 0xe8, 0x10, 0xb6, 0x68, 0xe4, 0x85, 0xab,
+	0xbe, 0x75, 0x6c, 0xbd, 0x68, 0x93, 0xdc, 0x40, 0x7d, 0xd8, 0x61, 0x79, 0x40, 0xbf, 0xa9, 0xfd,
+	0xc6, 0xc4, 0xbf, 0x2c, 0x68, 0x4f, 0x19, 0x4b, 0xd8, 0x24, 0x09, 0x28, 0x7a, 0x0e, 0xb6, 0x2f,
+	0xff, 0xeb, 0xc7, 0xdd, 0x71, 0x6f, 0x28, 0x93, 0x0c, 0xcb, 0xdb, 0xa1, 0xfa, 0x10, 0x1d, 0xa0,
+	0x00, 0x23, 0xca, 0xb9, 0x77, 0x43, 0x0d, 0x60, 0x61, 0xe2, 0x19, 0xd8, 0x1a, 0x6a, 0x0f, 0x76,
+	0xe6, 0x8b, 0xc9, 0x64, 0x3a, 0x9f, 0x3b, 0x0d, 0x04, 0xb0, 0x7d, 0x31, 0xfb, 0xe4, 0x92, 0x33,
+	0xc7, 0x52, 0x17, 0xa7, 0xee, 0x7b, 0x77, 0x71, 0x75, 0xee, 0x34, 0x95, 0xf1, 0xd9, 0x25, 0xb3,
+	0x8b, 0xd9, 0x99, 0xd3, 0x42, 0x3d, 0x15, 0x75, 0x35, 0x25, 0xc4, 0xf9, 0x63, 0xfe, 0x2c, 0xfc,
+	0x16, 0xf6, 0xdc, 0x4c, 0x2c, 0xff, 0xcf, 0x4f, 0x7a, 0x45, 0x72, 0x4b, 0xe3, 0xa2, 0x98, 0xdc,
+	0xc0, 0x27, 0xd0, 0x35, 0xf2, 0xd0, 0x60, 0xc1, 0x29, 0x43, 0x4f, 0x01, 0xfc, 0x55, 0x48, 0x63,
+	0x31, 0xa1, 0x4c, 0x14, 0x10, 0x15, 0x0f, 0xde, 0x81, 0xad, 0x69, 0x94, 0x8a, 0x3b, 0xfc, 0x1d,
+	0x7a, 0x97, 0x09, 0x17, 0x93, 0x24, 0x16, 0xcc, 0xf3, 0x85, 0xc9, 0x8e, 0xc0, 0x5e, 0x7a, 0x7c,
+	0xa9, 0x5f, 0xee, 0x13, 0x7d, 0x46, 0x03, 0xd8, 0xbd, 0x0e, 0x57, 0x34, 0xf6, 0x22, 0xa3, 0x45,
+	0x69, 0xa3, 0xc7, 0xb0, 0xcd, 0xc3, 0x9b, 0x98, 0xb2, 0x7e, 0xeb, 0xb8, 0x25, 0x6f, 0x0a, 0x4b,
+	0xc9, 0xe7, 0x27, 0x51, 0x24, 0xd3, 0xf6, 0xed, 0x5c, 0xbe, 0xc2, 0x94, 0xf2, 0x1d, 0x7e, 0x48,
+	0xc2, 0x78, 0x2e, 0xe3, 0x3c, 0x91, 0x31, 0x6a, 0x32, 0x63, 0xd8, 0xf7, 0x8b, 0x62, 0x16, 0x59,
+	0x18, 0x14, 0xb5, 0xd7, 0x7c, 0xaa, 0xba, 0x34, 0x61, 0x79, 0x8b, 0x3b, 0x44, 0x9f, 0xf1, 0x0f,
+	0x0b, 0x3a, 0x8a, 0xba, 0x64, 0x12, 0x53, 0x5f, 0xd0, 0x00, 0xbd, 0x82, 0x36, 0x35, 0x2d, 0xd5,
+	0x30, 0x7b, 0xe3, 0x6e, 0xbd, 0xd1, 0xe4, 0x3e, 0xe0, 0x9f, 0xbc, 0xcd, 0x0d, 0x79, 0x8f, 0xc0,
+	0xce, 0xb8, 0xe6, 0xa8, 0xc0, 0xda, 0x1a, 0x4c, 0xe5, 0x24, 0xda, 0x8d, 0xbf, 0x80, 0xad, 0xc5,
+	0x97, 0xa4, 0x6f, 0xe9, 0xdd, 0xf9, 0xbd, 0x7e, 0xc6, 0xbc, 0x6f, 0x6a, 0xb3, 0xda, 0xd4, 0x2e,
+	0x34, 0xc3, 0x54, 0x83, 0xb6, 0x89, 0x3c, 0x95, 0xf4, 0xec, 0x0a, 0xbd, 0x37, 0xe0, 0x10, 0xea,
+	0x05, 0x77, 0x4a, 0xaf, 0x07, 0x48, 0x85, 0x7f, 0x5a, 0x70, 0xf0, 0xd1, 0xcb, 0x62, 0x7f, 0x59,
+	0x2a, 0xfd, 0x40, 0x61, 0x9e, 0x41, 0x87, 0x9b, 0xa7, 0x15, 0x65, 0xea, 0xce, 0x2a, 0x67, 0x35,
+	0x01, 0x15, 0xce, 0x72, 0x6c, 0xb8, 0x2a, 0x38, 0xf6, 0xa9, 0x64, 0xd4, 0x92, 0x8c, 0x4a, 0x7b,
+	0xfc, 0xbb, 0x09, 0xbb, 0x97, 0xc5, 0xbe, 0xa3, 0x31, 0xec, 0x9a, 0x29, 0x46, 0x87, 0xba, 0x9e,
+	0xb5, 0x9d, 0x1f, 0xac, 0x55, 0x89, 0x1b, 0x68, 0x04, 0xb6, 0x5a, 0x1a, 0xe4, 0xe8, 0x9b, 0xca,
+	0xfe, 0x0c, 0x7a, 0x35, 0x84, 0x7c, 0x2d, 0xe4, 0x83, 0x97, 0x00, 0x8b, 0x98, 0x99, 0x34, 0x90,
+	0x03, 0xaa, 0x4d, 0xd8, 0x00, 0xfe, 0x0e, 0xf6, 0xab, 0xbb, 0x81, 0xfa, 0x3a, 0x62, 0xc3, 0xba,
+	0x6c, 0x78, 0x7b, 0x0a, 0x9d, 0xda, 0x78, 0xa3, 0x27, 0x3a, 0x64, 0xd3, 0xc8, 0x0f, 0x50, 0x39,
+	0x48, 0xe5, 0xf0, 0xe2, 0xc6, 0x89, 0x25, 0xf3, 0xb7, 0xcb, 0x9e, 0xa3, 0x47, 0x05, 0x9f, 0xfa,
+	0x0c, 0x0c, 0x72, 0xa1, 0xd6, 0x3a, 0x8c, 0x1b, 0x5f, 0xb7, 0xf5, 0xaf, 0xe7, 0xeb, 0xbf, 0x01,
+	0x00, 0x00, 0xff, 0xff, 0x3f, 0xa2, 0x07, 0x22, 0x5e, 0x05, 0x00, 0x00,
 }
diff --git a/dfssp/api/platform.proto b/dfssp/api/platform.proto
index 5dd180b581901cd0d0c508704799402c57d3b0f9..93f4887c568632f3c979a783c50ab332d8444218 100644
--- a/dfssp/api/platform.proto
+++ b/dfssp/api/platform.proto
@@ -94,4 +94,5 @@ message LaunchSignature {
 	ErrorCode errorCode = 1;
 	string signatureUuid = 2;
 	repeated bytes keyHash = 3;
+	repeated uint32 sequence = 4;
 }
diff --git a/dfssp/contract/file.go b/dfssp/contract/file.go
index 3a088a03f19669196ada3483a660556ec7311157..ebf4d721d3678868f65b074078305f4b26e9736d 100644
--- a/dfssp/contract/file.go
+++ b/dfssp/contract/file.go
@@ -29,13 +29,12 @@ type TTPJSON struct {
 
 // JSON is the structure used to store contract information in JSON format
 type JSON struct {
-	UUID     string
-	Date     *time.Time
-	Comment  string
-	File     *FileJSON
-	Signers  []SignerJSON
-	Sequence []uint
-	TTP      *TTPJSON
+	UUID    string
+	Date    *time.Time
+	Comment string
+	File    *FileJSON
+	Signers []SignerJSON
+	TTP     *TTPJSON
 }
 
 // GetJSON returns indented json from a contract and some ttp information (nil allowed)
diff --git a/dfssp/contract/file_test.go b/dfssp/contract/file_test.go
index 5a396f6a349652a9db767623da184e95ca871d84..33eb53ea283571b4fa543169229755bfdaa7730f 100644
--- a/dfssp/contract/file_test.go
+++ b/dfssp/contract/file_test.go
@@ -48,7 +48,6 @@ allow multiline and accents: éÉ`,
       "Hash": "bb"
     }
   ],
-  "Sequence": null,
   "TTP": null
 }`
 
diff --git a/dfssp/contract/join.go b/dfssp/contract/join.go
index 58262fe875a238bcf24f2ad403d9d3a0724cca87..3673672cc5e19514bfcad2a57a9f0433a51ba6e3 100644
--- a/dfssp/contract/join.go
+++ b/dfssp/contract/join.go
@@ -103,4 +103,3 @@ func sendUserToStream(stream *api.Platform_JoinSignatureServer, contractUUID str
 		User:         user,
 	})
 }
-
diff --git a/dfssp/contract/ready.go b/dfssp/contract/ready.go
index 5749531bf7063bb7d74217163a04e50813ef3696..f5dabcd86a7765d92aa6b41b9e931bf5716eb04b 100644
--- a/dfssp/contract/ready.go
+++ b/dfssp/contract/ready.go
@@ -14,9 +14,10 @@ import (
 
 // readySignal is the structure that is transmitted accross goroutines
 type readySignal struct {
-	ready bool     // If true, this is the ready signal. If not, this is a new connection signal
-	data  string   // Various data (CN or SignatureUUID)
-	chain [][]byte // Only used to broadcast hash chain (signers hashes in order)
+	ready    bool     // If true, this is the ready signal. If not, this is a new connection signal
+	data     string   // Various data (CN or SignatureUUID)
+	chain    [][]byte // Only used to broadcast hash chain (signers hashes in order)
+	sequence []uint32 // Only used to broadcast signature sequence
 }
 
 // ReadySign is the last job of the platform before the signature can occur.
@@ -108,9 +109,10 @@ func masterReadyRoutine(db *mgdb.MongoManager, rooms *common.WaitingGroupMap, co
 			ready := FindAndUpdatePendingSigner(cn, &signersReady, &contract.Signers)
 			if ready {
 				rooms.Broadcast(roomID, &readySignal{
-					ready: true,
-					data:  bson.NewObjectId().Hex(),
-					chain: contract.GetHashChain(),
+					ready:    true,
+					data:     bson.NewObjectId().Hex(),
+					chain:    contract.GetHashChain(),
+					sequence: GenerateSignSequence(len(contract.Signers)),
 				})
 				work = false
 			}
diff --git a/dfssp/contract/sequence.go b/dfssp/contract/sequence.go
index 796e752ff840efc43a71151dc830119c68e64fa4..eaf28f60d8b279b5fce66e4089aa461ee6f45184 100644
--- a/dfssp/contract/sequence.go
+++ b/dfssp/contract/sequence.go
@@ -1,23 +1,20 @@
 package contract
 
-import (
-	"dfss/dfssp/entities"
-)
-
 // GenerateSignSequence for the contract signature
 //
 // The generated sequence is an array of integers refering to the User array.
-func GenerateSignSequence(users []*entities.User) []int {
-	return SquaredSignEngine(len(users))
+func GenerateSignSequence(n int) []uint32 {
+	return SquaredSignEngine(uint32(n))
 }
 
 // SquaredSignEngine is a basic ^2 engine for sequence generation
-func SquaredSignEngine(n int) []int {
-	sequence := make([]int, n*n)
+func SquaredSignEngine(n uint32) []uint32 {
+	sequence := make([]uint32, n*n)
 
-	for i := 0; i < n; i++ {
-		for k := 0; k < n; k++ {
-			sequence[i*n+k] = k
+	var i, k uint32
+	for i = 0; i < n; i++ {
+		for k = 0; k < n; k++ {
+			sequence[i*n+k] = uint32(k)
 		}
 	}
 
@@ -25,17 +22,18 @@ func SquaredSignEngine(n int) []int {
 }
 
 // SquaredSignEngineSlice is the same as the above with slicing
-func SquaredSignEngineSlice(n int) []int {
-	baseSequence := make([]int, n)
+func SquaredSignEngineSlice(n uint32) []uint32 {
+	baseSequence := make([]uint32, n)
 
 	// populate base slice
-	for i := 0; i < n; i++ {
+	var i uint32
+	for i = 0; i < n; i++ {
 		baseSequence[i] = i
 	}
 
-	sequence := make([]int, 0, n*n)
+	sequence := make([]uint32, 0, n*n)
 	// append n-1 time the slice to itself
-	for i := 0; i < n; i++ {
+	for i = 0; i < n; i++ {
 		sequence = append(sequence, baseSequence...)
 	}
 
diff --git a/dfssp/contract/sequence_test.go b/dfssp/contract/sequence_test.go
index 2327a8bb91cc03a25c341ac723266d5b0f769973..e3097c0b36ab62ee5798e9851f0bfc87f64c47ad 100644
--- a/dfssp/contract/sequence_test.go
+++ b/dfssp/contract/sequence_test.go
@@ -2,30 +2,18 @@ package contract_test
 
 import (
 	"dfss/dfssp/contract"
-	"dfss/dfssp/entities"
 	"github.com/bmizerany/assert"
 	"testing"
 )
 
-var refSeq = []int{0, 1, 2, 0, 1, 2, 0, 1, 2} // for n = 3
+var refSeq = []uint32{0, 1, 2, 0, 1, 2, 0, 1, 2} // for n = 3
 
 func TestGenerateSignSequence(t *testing.T) {
-
-	// initialise fixtures
-	var users = make([]*entities.User, 3)
-	users[0] = entities.NewUser()
-	users[1] = entities.NewUser()
-	users[2] = entities.NewUser()
-	users[0].Email = "user1@example.com"
-	users[1].Email = "user2@example.com"
-	users[2].Email = "user3@example.com"
-
-	assert.Equal(t, refSeq, contract.GenerateSignSequence(users))
+	assert.Equal(t, refSeq, contract.GenerateSignSequence(3))
 }
 
 // Perform sequence generation in a loop
 func BenchmarkSquaredEngine(b *testing.B) {
-
 	for i := 0; i < b.N; i++ {
 		_ = contract.SquaredSignEngine(10)
 	}
@@ -33,7 +21,6 @@ func BenchmarkSquaredEngine(b *testing.B) {
 
 // Perform sequence generation in a loop with slicing
 func BenchmarkSquaredEngineSlice(b *testing.B) {
-
 	for i := 0; i < b.N; i++ {
 		_ = contract.SquaredSignEngineSlice(10)
 	}
diff --git a/tests/sign_test.go b/tests/sign_test.go
index 6f9f304089ec6fcb1d9a1ac77e6bd26e48575175..115078c1a6dd3dcb759cba2c7e870609d48e0078 100644
--- a/tests/sign_test.go
+++ b/tests/sign_test.go
@@ -32,15 +32,15 @@ func TestSignContract(t *testing.T) {
 
 	// Register clients
 	clients := make([]*exec.Cmd, 3)
-	client1, err := createClient(workingDir, ca, 0)
+	client1, err := createClient(workingDir, ca, 9091)
 	assert.Equal(t, nil, err)
 	err = registerAndAuth(client1, "client1@example.com", "password", "", true, true)
 	assert.Equal(t, nil, err)
-	client2, err := createClient(workingDir, ca, 0)
+	client2, err := createClient(workingDir, ca, 9092)
 	assert.Equal(t, nil, err)
 	err = registerAndAuth(client2, "client2@example.com", "password", "", true, true)
 	assert.Equal(t, nil, err)
-	client3, err := createClient(workingDir, ca, 0)
+	client3, err := createClient(workingDir, ca, 9093)
 	assert.Equal(t, nil, err)
 	err = registerAndAuth(client3, "client3@example.com", "password", "", true, true)
 	assert.Equal(t, nil, err)
@@ -80,6 +80,7 @@ func TestSignContract(t *testing.T) {
 		go func(c *exec.Cmd, i int) {
 			time.Sleep(time.Duration(i*2) * time.Second)
 			c.Stdin = strings.NewReader("password\nyes\n")
+			c.Stderr = os.Stderr
 			output, err := c.Output()
 			if err != nil {
 				output = nil
diff --git a/tests/starters_test.go b/tests/starters_test.go
index a82bd8bdb352db411af25d286208c2299add824f..a0ca586295201a177b31e3990b2dd8e4e5514bc8 100644
--- a/tests/starters_test.go
+++ b/tests/starters_test.go
@@ -73,7 +73,7 @@ func createClient(tmpDir string, ca []byte, port int) (*exec.Cmd, error) {
 
 	// Prepare the client command.
 	// The last argument is up to you!
-	cmd := exec.Command(path, "-ca", caPath, "-cert", certPath, "-host", "127.0.0.1:"+testPort, "-key", keyPath, "-port", strconv.Itoa(port),  "-v")
+	cmd := exec.Command(path, "-ca", caPath, "-cert", certPath, "-host", "127.0.0.1:"+testPort, "-key", keyPath, "-port", strconv.Itoa(port), "-v")
 
 	return cmd, nil
 }