diff --git a/swh/core/bencode.py b/swh/core/bencode.py
new file mode 100644
--- /dev/null
+++ b/swh/core/bencode.py
@@ -0,0 +1,52 @@
+# Copyright (C) 2019 The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+from typing import List, Dict, Callable, Any
+
+
+def _encode_bytes(parts: List[bytes], obj: bytes) -> None:
+    parts.append(b'%d:' % len(obj))
+    parts.append(obj)
+
+
+def _encode_int(parts: List[bytes], obj: int) -> None:
+    parts.append(b'i%de' % obj)
+
+
+def _encode_list(parts: List[bytes], obj: list) -> None:
+    parts.append(b'l')
+    for item in obj:
+        _encode(parts, item)
+    parts.append(b'e')
+
+
+def _encode_dict(parts: List[bytes], obj: dict) -> None:
+    parts.append(b'd')
+    for (key, value) in sorted(obj.items()):
+        assert type(key) == bytes
+        _encode_bytes(parts, key)
+        _encode(parts, value)
+    parts.append(b'e')
+
+
+ENCODERS = {
+    bytes: _encode_bytes,
+    int: _encode_int,
+    list: _encode_list,
+    dict: _encode_dict,
+}  # type: Dict[type, Callable[[List[bytes], Any], None]]
+
+
+def _encode(parts: List[bytes], obj: Any) -> None:
+    ENCODERS[type(obj)](parts, obj)
+
+
+def encode(obj) -> bytes:
+    """Encodes a nested bytes/int/list/dict structure into its bencode
+    representation.
+    """
+    parts = []  # type: List[bytes]
+    _encode(parts, obj)
+    return b''.join(parts)
diff --git a/swh/core/tests/test_bencode.py b/swh/core/tests/test_bencode.py
new file mode 100644
--- /dev/null
+++ b/swh/core/tests/test_bencode.py
@@ -0,0 +1,43 @@
+# Copyright (C) 2019 The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+from swh.core.bencode import encode
+
+# The examples are from the specification:
+# https://wiki.theory.org/index.php/BitTorrentSpecification#Bencoding
+
+
+def test_bencode_bytes():
+    assert b'4:spam' == encode(b'spam')
+
+    assert b'0:' == encode(b'')
+
+
+def test_encode_int():
+    assert b'i3e' == encode(3)
+
+    assert b'i-3e' == encode(-3)
+
+    assert b'i0e' == encode(0)
+
+
+def test_encode_list():
+    assert b'l4:spam4:eggse' == encode([b'spam', b'eggs'])
+
+    assert b'le' == encode([])
+
+
+def test_encode_dict():
+    assert b'd3:cow3:moo4:spam4:eggse' == \
+        encode({b'cow': b'moo', b'spam': b'eggs'})
+
+    assert b'd4:spaml1:a1:bee' == encode({b'spam': [b'a', b'b']})
+
+    assert (b'd9:publisher3:bob17:publisher-webpage15:www.example.com'
+            b'18:publisher.location4:homee') == \
+        encode({b'publisher': b'bob', b'publisher-webpage': b'www.example.com',
+                b'publisher.location': b'home'})
+
+    assert b'de' == encode({})