diff --git a/libp2p/peer/id.py b/libp2p/peer/id.py
index 9ad8821..48b4892 100644
--- a/libp2p/peer/id.py
+++ b/libp2p/peer/id.py
@@ -82,38 +82,6 @@ class ID:
         return cls.from_pubkey(key.publickey())
 
 
-def id_b58_encode(peer_id: ID) -> str:
-    """
-    return a b58-encoded string
-    """
-    # pylint: disable=protected-access
-    return base58.b58encode(peer_id.to_bytes()).decode()
-
-
-def id_b58_decode(b58_encoded_peer_id_str: str) -> ID:
-    """
-    return a base58-decoded peer ID
-    """
-    return ID(base58.b58decode(b58_encoded_peer_id_str))
-
-
-def id_from_public_key(key: RsaKey) -> ID:
-    # export into binary format
-    key_bin = key.exportKey("DER")
-
-    algo: int = multihash.Func.sha2_256
-    # TODO: seems identity is not yet supported in pymultihash
-    # if len(b) <= MAX_INLINE_KEY_LENGTH:
-    #     algo multihash.func.identity
-
-    mh_digest: multihash.Multihash = multihash.digest(key_bin, algo)
-    return ID(mh_digest.encode())
-
-
-def id_from_private_key(key: RsaKey) -> ID:
-    return id_from_public_key(key.publickey())
-
-
 def digest(data: Union[str, bytes]) -> bytes:
     if isinstance(data, str):
         data = data.encode("utf8")
diff --git a/libp2p/transport/tcp/tcp.py b/libp2p/transport/tcp/tcp.py
index 8f88430..e497c73 100644
--- a/libp2p/transport/tcp/tcp.py
+++ b/libp2p/transport/tcp/tcp.py
@@ -3,7 +3,7 @@ import asyncio
 import multiaddr
 
 from libp2p.network.connection.raw_connection import RawConnection
-from libp2p.peer.id import id_b58_encode
+from libp2p.peer.id import ID
 
 from ..listener_interface import IListener
 from ..transport_interface import ITransport
@@ -74,7 +74,7 @@ class TCP(ITransport):
         reader, writer = await asyncio.open_connection(host, port)
 
         # First: send our peer ID so receiver knows it
-        writer.write(id_b58_encode(self_id).encode())
+        writer.write(self_id.to_base58().encode())
         await writer.drain()
 
         # Await ack for peer id