diff --git a/tests/test_signer.py b/tests/test_signer.py
index b0bc16d9..bae7b506 100644
--- a/tests/test_signer.py
+++ b/tests/test_signer.py
@@ -20,10 +20,10 @@
 import unittest
 import securesystemslib.formats
 import securesystemslib.keys as KEYS
-from securesystemslib.signer import SSlibSigner
+from securesystemslib.signer import Signature, SSlibSigner
+import securesystemslib.exceptions as exceptions
 
-
-class TestSSlibSigner(unittest.TestCase):\
+class TestSSlibSigner(unittest.TestCase):
 
   @classmethod
   def setUpClass(cls):
@@ -38,63 +38,48 @@ def setUpClass(cls):
 
 
   def test_sslib_sign(self):
-    # Test generation of RSA signatures.
-    sslib_signer = SSlibSigner(self.rsakey_dict)
-    rsa_sig_obj = sslib_signer.sign(self.DATA)
-
-    # Verify rsa signature
-    verified = KEYS.verify_signature(self.rsakey_dict,
-        rsa_sig_obj.to_dict(), self.DATA)
-
-    # Verify rsa signature
-    verified = KEYS.verify_signature(self.rsakey_dict,
-        rsa_sig_obj.to_dict(), self.DATA)
-    self.assertTrue(verified, "Incorrect signature.")
-
-    # Test for invalid signature scheme.
-    valid_scheme = self.rsakey_dict['scheme']
-    self.rsakey_dict['scheme'] = 'invalid_scheme'
-    sslib_signer.key_dict = self.rsakey_dict
+    for scheme_dict in [self.rsakey_dict, self.ecdsakey_dict]:
+      # Test generation of signatures.
+      sslib_signer = SSlibSigner(scheme_dict)
+      sig_obj = sslib_signer.sign(self.DATA)
 
-    self.assertRaises(securesystemslib.exceptions.UnsupportedAlgorithmError,
-        sslib_signer.sign, self.DATA)
-    self.rsakey_dict['scheme'] = valid_scheme
+      # Verify signature
+      verified = KEYS.verify_signature(scheme_dict, sig_obj.to_dict(), self.DATA)
+      self.assertTrue(verified, "Incorrect signature.")
 
-    # Removing private key from 'rsakey_dict' - should raise a TypeError.
-    private = self.rsakey_dict['keyval']['private']
-    self.rsakey_dict['keyval']['private'] = ''
-    sslib_signer.key_dict = self.rsakey_dict
+      # Removing private key from 'scheme_dict' - should raise a ValueError.
+      private = scheme_dict['keyval']['private']
+      scheme_dict['keyval']['private'] = ''
+      sslib_signer.key_dict = scheme_dict
 
-    self.assertRaises(ValueError, sslib_signer.sign, self.DATA)
+      with self.assertRaises(ValueError):
+        sslib_signer.sign(self.DATA)
 
-    # Supplying an incorrect number of arguments.
-    self.assertRaises(TypeError, KEYS.create_signature)
-    self.rsakey_dict['keyval']['private'] = private
+      scheme_dict['keyval']['private'] = private
 
-    # Test generation of ECDSA signatures.
+      # Supplying an incorrect number of arguments.
+      with self.assertRaises(TypeError):
+        sslib_signer.sign()
 
-    sslib_signer.key_dict = self.ecdsakey_dict
-    # Creating a signature for 'DATA'.
-    ecdsa_sig = sslib_signer.sign(self.DATA)
+    # Test for invalid signature scheme.
+    valid_scheme = self.rsakey_dict['scheme']
+    self.rsakey_dict['scheme'] = 'invalid_scheme'
+    sslib_signer = SSlibSigner(self.rsakey_dict)
 
-    # Verify rsa signature
-    verified = KEYS.verify_signature(self.ecdsakey_dict,
-        ecdsa_sig.to_dict(), self.DATA)
+    with self.assertRaises(exceptions.UnsupportedAlgorithmError):
+        sslib_signer.sign(self.DATA)
 
-    # Verify rsa signature
-    verified = KEYS.verify_signature(self.ecdsakey_dict,
-        ecdsa_sig.to_dict(), self.DATA)
-    self.assertTrue(verified, "Incorrect signature.")
+    self.rsakey_dict['scheme'] = valid_scheme
 
-    # Removing private key from 'ecdsakey_dict' - should raise a TypeError.
-    private = self.ecdsakey_dict['keyval']['private']
-    self.ecdsakey_dict['keyval']['private'] = ''
 
-    self.assertRaises(ValueError, sslib_signer.sign, self.DATA)
+  def test_signature_from_to_json(self):
+    signature_dict = {
+      "sig": "30460221009342e4566528fcecf6a7a5d53ebacdb1df151e242f55f8775883469cb01dbc6602210086b426cc826709acfa2c3f9214610cb0a832db94bbd266fd7c5939a48064a851",
+      "keyid": "11fa391a0ed7a447cbfeb4b2667e286fc248f64d5e6d0eeed2e5e23f97f9f714"
+    }
+    sig_obj = Signature.from_dict(signature_dict)
 
-    # Supplying an incorrect number of arguments.
-    self.assertRaises(TypeError, sslib_signer.sign)
-    self.ecdsakey_dict['keyval']['private'] = private
+    self.assertEqual(signature_dict, sig_obj.to_dict())
 
 
 # Run the unit tests.