diff '--color=auto' -ruN a/src/model/transport.py b/src/model/transport.py
--- a/src/model/transport.py	2025-08-27 17:12:23.761436314 +0200
+++ b/src/model/transport.py	2025-08-27 17:17:35.723006746 +0200
@@ -105,7 +105,6 @@
     MSG_NAMES,
 )
 from paramiko.compress import ZlibCompressor, ZlibDecompressor
-from paramiko.dsskey import DSSKey
 from paramiko.ed25519key import Ed25519Key
 from paramiko.kex_curve25519 import KexCurve25519
 from paramiko.kex_gex import KexGex, KexGexSHA256
@@ -117,7 +116,6 @@
 from paramiko.message import Message
 from paramiko.packet import Packetizer, NeedRekeyException
 from paramiko.primes import ModulusPack
-from paramiko.py3compat import string_types, long, byte_ord, b, input, PY2
 from paramiko.rsakey import RSAKey
 from paramiko.ecdsakey import ECDSAKey
 from paramiko.server import ServerInterface
@@ -128,7 +126,7 @@
     ChannelException,
     ProxyCommandFailure,
 )
-from paramiko.util import retry_on_signal, ClosingContextManager, clamp_value
+from paramiko.util import ClosingContextManager, clamp_value
 
 
 # for thread cleanup
@@ -192,7 +190,6 @@
         "ecdsa-sha2-nistp384",
         "ecdsa-sha2-nistp521",
         "ssh-rsa",
-        "ssh-dss",
     )
     _preferred_kex = (
         "ecdh-sha2-nistp256",
@@ -273,8 +270,6 @@
     _key_info = {
         "ssh-rsa": RSAKey,
         "ssh-rsa-cert-v01@openssh.com": RSAKey,
-        "ssh-dss": DSSKey,
-        "ssh-dss-cert-v01@openssh.com": DSSKey,
         "ecdsa-sha2-nistp256": ECDSAKey,
         "ecdsa-sha2-nistp256-cert-v01@openssh.com": ECDSAKey,
         "ecdsa-sha2-nistp384": ECDSAKey,
@@ -396,7 +391,7 @@
         self.active = False
         self.hostname = None
 
-        if isinstance(sock, string_types):
+        if isinstance(sock, str):
             # convert "host:port" into (host, port)
             hl = sock.split(":", 1)
             self.hostname = hl[0]
@@ -419,7 +414,7 @@
                     sock = socket.socket(af, socket.SOCK_STREAM)
                     sock.settimeout(1)
                     try:
-                        retry_on_signal(lambda: sock.connect((hostname, port)))
+                        sock.connect((hostname, port))
                     except socket.error as e:
                         reason = str(e)
                     else:
@@ -542,7 +537,7 @@
         """
         Returns a string representation of this object, for debugging.
         """
-        id_ = hex(long(id(self)) & xffffffff)
+        id_ = hex(int(id(self)) & xffffffff)
         out = "<paramiko.Transport at {}".format(id_)
         if not self.active:
             out += " (unconnected)"
@@ -749,11 +744,11 @@
         as a server, the host key is used to sign certain packets during the
         SSH2 negotiation, so that the client can trust that we are who we say
         we are.  Because this is used for signing, the key must contain private
-        key info, not just the public half.  Only one key of each type (RSA or
-        DSS) is kept.
+        key info, not just the public half.  Only one key of each type (i.e.
+        RSA) is kept.
 
         :param .PKey key:
-            the host key to add, usually an `.RSAKey` or `.DSSKey`.
+            the host key to add, usually an `.RSAKey`.
         """
         self.server_key_dict[key.get_name()] = key
 
@@ -763,7 +758,7 @@
         client, this method will return the negotiated host key.  If only one
         type of host key was set with `add_server_key`, that's the only key
         that will ever be returned.  But in cases where you have set more than
-        one type of host key (for example, an RSA key and a DSS key), the key
+        one type of host key (for example, an RSA key and another key), the key
         type will be negotiated by the client, and this method will return the
         key of the type agreed on.  If the host key has not been negotiated
         yet, ``None`` is returned.  In client mode, the behavior is undefined.
@@ -1123,7 +1118,7 @@
         m = Message()
         m.add_byte(cMSG_IGNORE)
         if byte_count is None:
-            byte_count = (byte_ord(os.urandom(1)) % 32) + 10
+            byte_count = (os.urandom(1) % 32) + 10
         m.add_bytes(os.urandom(byte_count))
         self._send_user_message(m)
 
@@ -1802,7 +1797,7 @@
     def stop_thread(self):
         self.active = False
         self.packetizer.close()
-        if PY2:
+        if False:
             # Original join logic; #520 doesn't appear commonly present under
             # Python 2.
             while self.is_alive() and self is not threading.current_thread():
@@ -1909,7 +1904,7 @@
         m = Message()
         m.add_mpint(self.K)
         m.add_bytes(self.H)
-        m.add_byte(b(id))
+        m.add_byte(id.encode("utf8"))
         m.add_bytes(self.session_id)
         # Fallback to SHA1 for kex engines that fail to specify a hex
         # algorithm, or for e.g. transport tests that don't run kexinit.
@@ -2037,14 +2032,14 @@
 
         # active=True occurs before the thread is launched, to avoid a race
         _active_threads.append(self)
-        tid = hex(long(id(self)) & xffffffff)
+        tid = hex(int(id(self)) & xffffffff)
         if self.server_mode:
             self._log(DEBUG, "starting thread (server mode): {}".format(tid))
         else:
             self._log(DEBUG, "starting thread (client mode): {}".format(tid))
         try:
             try:
-                self.packetizer.write_all(b(self.local_version + "\r\n"))
+                self.packetizer.write_all((self.local_version + "\r\n").encode("utf8"))
                 self._log(
                     DEBUG,
                     "Local version/idstring: {}".format(self.local_version),