diff --git a/model/group.go b/model/group.go
index b43fbcc..109ef3b 100644
--- a/model/group.go
+++ b/model/group.go
@@ -26,6 +26,7 @@ type Group struct {
 	Owner          string
 	IsCompromised  bool
 	InitialMessage []byte
+	Constructed bool
 	lock           sync.Mutex
 	NewMessage     chan Message `json:"-"`
 }
diff --git a/model/profile.go b/model/profile.go
index 0563cb0..beb4be7 100644
--- a/model/profile.go
+++ b/model/profile.go
@@ -246,6 +246,7 @@ func (p *Profile) ProcessInvite(gci *protocol.GroupChatInvite, peerHostname stri
 	group.InitialMessage = gci.GetInitialMessage()[:]
 	group.Accepted = false
 	group.Owner = peerHostname
+	group.SignedGroupID = []byte{}
 	p.AddGroup(group)
 }
 
@@ -261,6 +262,10 @@ func (p *Profile) AddGroup(group *Group) {
 				defer p.lock.Unlock()
 				p.Groups[group.GroupID] = group
 			}
+		} else if group.Constructed {
+			p.lock.Lock()
+			defer p.lock.Unlock()
+			p.Groups[group.GroupID] = group
 		}
 	} else if exists && existingGroup.Owner == group.Owner {
 		p.lock.Lock()
@@ -286,7 +291,7 @@ func (p *Profile) AttemptDecryption(ciphertext []byte, signature []byte) (bool,
 				// this message is from someone who was not invited to the group.
 				// As such this group has been compromised, probably by one of the other members.
 				// We set the flag to be handled by the UX and reject the message.
-				if !valid {
+				if !valid && !group.Constructed {
 					group.Compromised()
 					return false, nil
 				}
@@ -328,7 +333,7 @@ func (p *Profile) EncryptMessageToGroup(message string, groupID string) ([]byte,
 			prevSig = group.SignedGroupID
 		}
 
-		lenPadding := 1024 - len(message)
+		lenPadding := 1800 - len(message)
 		padding := make([]byte, lenPadding)
 		getRandomness(&padding)