diff --git a/electrum/lntransport.py b/electrum/lntransport.py
index f3c111112..72a5f172c 100644
--- a/electrum/lntransport.py
+++ b/electrum/lntransport.py
@@ -105,19 +105,19 @@ class LNTransportBase:
         self.writer.write(lc+c)
 
     async def read_messages(self):
-        read_buffer = b''
+        buffer = bytearray()
         while True:
             rn_l, rk_l = self.rn()
             rn_m, rk_m = self.rn()
             while True:
-                if len(read_buffer) >= 18:
-                    lc = read_buffer[:18]
+                if len(buffer) >= 18:
+                    lc = bytes(buffer[:18])
                     l = aead_decrypt(rk_l, rn_l, b'', lc)
                     length = int.from_bytes(l, 'big')
                     offset = 18 + length + 16
-                    if len(read_buffer) >= offset:
-                        c = read_buffer[18:offset]
-                        read_buffer = read_buffer[offset:]
+                    if len(buffer) >= offset:
+                        c = bytes(buffer[18:offset])
+                        del buffer[:offset]  # much faster than: buffer=buffer[offset:]
                         msg = aead_decrypt(rk_m, rn_m, b'', c)
                         yield msg
                         break
@@ -129,7 +129,7 @@ class LNTransportBase:
                     s = None
                 if not s:
                     raise LightningPeerConnectionClosed()
-                read_buffer += s
+                buffer += s
 
     def rn(self):
         o = self._rn, self.rk