diff --git a/models/resources/interfaces.go b/models/resources/interfaces.go
index 501354b..c8798f4 100755
--- a/models/resources/interfaces.go
+++ b/models/resources/interfaces.go
@@ -20,7 +20,7 @@ type ResourceInterface interface {
 	SetAllowedInstances(request *tools.APIRequest)
 	AddInstances(instance ResourceInstanceITF)
 	RefineResourceByPartnership(peerID string) ResourceInterface
-	GetSignature() string
+	GetSignature() []byte
 }
 
 type ResourceInstanceITF interface {
diff --git a/models/resources/resource.go b/models/resources/resource.go
index e6cd778..9bd3f17 100755
--- a/models/resources/resource.go
+++ b/models/resources/resource.go
@@ -27,10 +27,10 @@ type AbstractResource struct {
 	Owners               []utils.Owner                                     `json:"owners,omitempty" bson:"owners,omitempty"`                                           // Owners is the list of owners of the resource
 	UsageRestrictions    string                                            `bson:"usage_restrictions,omitempty" json:"usage_restrictions,omitempty"`
 	AllowedBookingModes  map[booking.BookingMode]*pricing.PricingVariation `bson:"allowed_booking_modes" json:"allowed_booking_modes"`
-	Signature            string                                            `bson:"signature" json:"signature"`
+	Signature            []byte                                            `bson:"signature" json:"signature"`
 }
 
-func (abs *AbstractResource) GetSignature() string {
+func (abs *AbstractResource) GetSignature() []byte {
 	return abs.Signature
 }