diff --git a/tests/test_signature.py b/tests/test_signature.py
new file mode 100644
index 0000000..1d8a576
--- /dev/null
+++ b/tests/test_signature.py
@@ -0,0 +1,77 @@
+# bijoe - BI dashboard
+# Copyright (C) 2020  Entr'ouvert
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# from https://git.entrouvert.org/hobo.git/tree/tests/test_signature.py
+import datetime
+
+from django.utils.six.moves.urllib import parse as urllib
+
+from bijoe.visualization import signature
+
+
+def test_signature():
+    KEY = 'xyz'
+    STRING = 'aaa'
+    URL = 'http://example.net/api/?coucou=zob'
+    QUERY = 'coucou=zob'
+    OTHER_KEY = 'abc'
+
+    # Passing test
+    assert signature.check_string(STRING, signature.sign_string(STRING, KEY), KEY)
+    assert signature.check_query(signature.sign_query(QUERY, KEY), KEY)
+    assert signature.check_url(signature.sign_url(URL, KEY), KEY)
+
+    # Not passing tests
+    assert not signature.check_string(STRING, signature.sign_string(STRING, KEY), OTHER_KEY)
+    assert not signature.check_query(signature.sign_query(QUERY, KEY), OTHER_KEY)
+    assert not signature.check_url(signature.sign_url(URL, KEY), OTHER_KEY)
+    #assert not signature.check_url('%s&foo=bar' % signature.sign_url(URL, KEY), KEY)
+
+    # Test URL is preserved
+    assert URL in signature.sign_url(URL, KEY)
+    assert QUERY in signature.sign_query(QUERY, KEY)
+
+    # Test signed URL expected parameters
+    assert '&algo=sha256&' in signature.sign_url(URL, KEY)
+    assert '&timestamp=' in signature.sign_url(URL, KEY)
+    assert '&nonce=' in signature.sign_url(URL, KEY)
+
+    # Test unicode key conversion to UTF-8
+    assert signature.check_url(signature.sign_url(URL, u'\xe9\xe9'), b'\xc3\xa9\xc3\xa9')
+    assert signature.check_url(signature.sign_url(URL, b'\xc3\xa9\xc3\xa9'), u'\xe9\xe9')
+
+    # Test timedelta parameter
+    now = datetime.datetime.utcnow()
+    assert '&timestamp=%s' % urllib.quote(now.strftime('%Y-%m-%dT%H:%M:%SZ')) in \
+        signature.sign_url(URL, KEY, timestamp=now)
+
+    # Test nonce parameter
+    assert '&nonce=uuu&' in signature.sign_url(URL, KEY, nonce='uuu')
+
+    # Test known_nonce
+    assert signature.check_url(signature.sign_url(URL, KEY), KEY,
+                               known_nonce=lambda nonce: nonce == 'xxx')
+    assert signature.check_url(signature.sign_url(URL, KEY, nonce='xxx'), KEY,
+                               known_nonce=lambda nonce: nonce == 'xxx')
+
+    # Test timedelta
+    now = (datetime.datetime.utcnow() - datetime.timedelta(seconds=29))
+    assert signature.check_url(signature.sign_url(URL, KEY, timestamp=now), KEY)
+    now = (datetime.datetime.utcnow() - datetime.timedelta(seconds=30))
+    assert not signature.check_url(signature.sign_url(URL, KEY, timestamp=now), KEY)
+    now = (datetime.datetime.utcnow() - datetime.timedelta(seconds=2))
+    assert signature.check_url(signature.sign_url(URL, KEY, timestamp=now), KEY)
+    assert signature.check_url(signature.sign_url(URL, KEY, timestamp=now), KEY, timedelta=2)