Merge pull request #72 from tomato42/docs-for-default-kyber

document the default Kyber parameters, minor fix in Kyber docs

src/kyber_py/kyber/default_parameters.py

@@ -24,8 +24,30 @@
         "dv": 5,
     },
 }
+"""
+Lattice parameters for the Kyber key exchange.
+
+To be used for initialisation of :py:obj:`.Kyber` objects.
+"""
 
 # Initialise with default parameters for easy import
 Kyber512 = Kyber(DEFAULT_PARAMETERS["kyber_512"])
+"""
+Key exchange object that uses Kyber512 parameters internally.
+
+Provides about 128 bit level of security.
+"""
+
 Kyber768 = Kyber(DEFAULT_PARAMETERS["kyber_768"])
+"""
+Key exchange object that uses Kyber768 parameters internally.
+
+Provides about 192 bit level of security.
+"""
+
 Kyber1024 = Kyber(DEFAULT_PARAMETERS["kyber_1024"])
+"""
+Key exchange object that uses Kyber1024 parameters internally.
+
+Provides about 256 bit level of security.
+"""

src/kyber_py/kyber/kyber.py

@@ -295,7 +295,7 @@ def encaps(self, pk, key_length=32):
 
         :param bytes pk: byte-encoded public key
         :param int key_length: length of secret key, default value 32
-        :return: a random key and an public of it
+        :return: a random key and a ciphertext of it
         :rtype: tuple(bytes, bytes)
         """
         # Compute random message