diff --git a/kmip/core/exceptions.py b/kmip/core/exceptions.py
index c238171..fcab164 100644
--- a/kmip/core/exceptions.py
+++ b/kmip/core/exceptions.py
@@ -19,3 +19,11 @@ class InvalidKmipEncoding(Exception):
     An exception raised when processing invalid KMIP message encodings.
     """
     pass
+
+
+class InvalidPrimitiveLength(Exception):
+    """
+    An exception raised for errors when processing primitives with invalid
+    lengths.
+    """
+    pass
diff --git a/kmip/core/primitives.py b/kmip/core/primitives.py
index adb4d3a..c8003e3 100644
--- a/kmip/core/primitives.py
+++ b/kmip/core/primitives.py
@@ -26,6 +26,7 @@ from kmip.core.enums import Tags
 from kmip.core.errors import ErrorStrings
 
 from kmip.core import errors
+from kmip.core import exceptions
 from kmip.core import utils
 
 
@@ -249,51 +250,110 @@ class Integer(Base):
 
 
 class LongInteger(Base):
+    """
+    An encodeable object representing a long integer value.
+
+    A LongInteger is one of the KMIP primitive object types. It is encoded as
+    a signed, big-endian, 64-bit integer. For more information, see Section
+    9.1 of the KMIP 1.1 specification.
+    """
+
     LENGTH = 8
 
-    def __init__(self, value=None, tag=Tags.DEFAULT):
+    # Bounds for signed 64-bit integers
+    MIN = -9223372036854775808
+    MAX = 9223372036854775807
+
+    def __init__(self, value=0, tag=Tags.DEFAULT):
+        """
+        Create a LongInteger.
+
+        Args:
+            value (int): The value of the LongInteger. Optional, defaults to 0.
+            tag (Tags): An enumeration defining the tag of the LongInteger.
+                Optional, defaults to Tags.DEFAULT.
+        """
         super(LongInteger, self).__init__(tag, type=Types.LONG_INTEGER)
         self.value = value
-        self.length = self.LENGTH
+        self.length = LongInteger.LENGTH
 
         self.validate()
 
-    def read_value(self, istream):
-        if self.length is not self.LENGTH:
-            raise errors.ReadValueError(LongInteger.__name__, 'length',
-                                        self.LENGTH, self.length)
+    def read(self, istream):
+        """
+        Read the encoding of the LongInteger from the input stream.
+
+        Args:
+            istream (stream): A buffer containing the encoded bytes of a
+                LongInteger. Usually a BytearrayStream object. Required.
+
+        Raises:
+            InvalidPrimitiveLength: if the long integer encoding read in has
+                an invalid encoded length.
+        """
+        super(LongInteger, self).read(istream)
+
+        if self.length is not LongInteger.LENGTH:
+            raise exceptions.InvalidPrimitiveLength(
+                "invalid long integer length read; "
+                "expected: {0}, observed: {1}".format(
+                    LongInteger.LENGTH, self.length))
 
         self.value = unpack('!q', istream.read(self.length))[0]
         self.validate()
 
-    def read(self, istream):
-        super(LongInteger, self).read(istream)
-        self.read_value(istream)
+    def write(self, ostream):
+        """
+        Write the encoding of the LongInteger to the output stream.
 
-    def write_value(self, ostream):
+        Args:
+            ostream (stream): A buffer to contain the encoded bytes of a
+                LongInteger. Usually a BytearrayStream object. Required.
+        """
+        super(LongInteger, self).write(ostream)
         ostream.write(pack('!q', self.value))
 
-    def write(self, ostream):
-        super(LongInteger, self).write(ostream)
-        self.write_value(ostream)
-
     def validate(self):
-        self.__validate()
+        """
+        Verify that the value of the LongInteger is valid.
 
-    def __validate(self):
+        Raises:
+            TypeError: if the value is not of type int or long
+            ValueError: if the value cannot be represented by a signed 64-bit
+                integer
+        """
         if self.value is not None:
-            data_type = type(self.value)
-            if data_type not in six.integer_types:
-                raise errors.StateTypeError(
-                    LongInteger.__name__, "{0}".format(six.integer_types),
-                    data_type)
-            num_bytes = utils.count_bytes(self.value)
-            if num_bytes > self.length:
-                raise errors.StateOverflowError(
-                    LongInteger.__name__, 'value', self.length, num_bytes)
+            if not isinstance(self.value, six.integer_types):
+                raise TypeError('expected (one of): {0}, observed: {1}'.format(
+                    six.integer_types, type(self.value)))
+            else:
+                if self.value > LongInteger.MAX:
+                    raise ValueError(
+                        'long integer value greater than accepted max')
+                elif self.value < LongInteger.MIN:
+                    raise ValueError(
+                        'long integer value less than accepted min')
 
     def __repr__(self):
-        return '<Long Integer, %d>' % (self.value)
+        return "LongInteger(value={0}, tag={1})".format(self.value, self.tag)
+
+    def __str__(self):
+        return str(self.value)
+
+    def __eq__(self, other):
+        if isinstance(other, LongInteger):
+            if self.value == other.value:
+                return True
+            else:
+                return False
+        else:
+            return NotImplemented
+
+    def __ne__(self, other):
+        if isinstance(other, LongInteger):
+            return not self.__eq__(other)
+        else:
+            return NotImplemented
 
 
 class BigInteger(Base):
diff --git a/kmip/tests/unit/core/primitives/test_long_integer.py b/kmip/tests/unit/core/primitives/test_long_integer.py
index 420d7bf..95e8785 100644
--- a/kmip/tests/unit/core/primitives/test_long_integer.py
+++ b/kmip/tests/unit/core/primitives/test_long_integer.py
@@ -15,195 +15,344 @@
 
 import testtools
 
-from kmip.core import errors
+from kmip.core import exceptions
 from kmip.core import primitives
 from kmip.core import utils
 
 
 class TestLongInteger(testtools.TestCase):
+    """
+    Test suite for the LongInteger primitive.
+    """
 
     def setUp(self):
         super(TestLongInteger, self).setUp()
-        self.stream = utils.BytearrayStream()
-        self.max_byte_long = 18446744073709551615
-        self.max_long = 9223372036854775807
-        self.bad_value = (
-            'Bad primitives.LongInteger.{0} after init: expected {1}, '
-            'received {2}')
-        self.bad_write = (
-            'Bad primitives.LongInteger write: expected {0} bytes, '
-            'received {1} bytes')
-        self.bad_encoding = (
-            'Bad primitives.LongInteger write: encoding mismatch')
-        self.bad_read = (
-            'Bad primitives.LongInteger.value read: expected {0}, '
-            'received {1}')
 
     def tearDown(self):
         super(TestLongInteger, self).tearDown()
 
     def test_init(self):
-        i = primitives.LongInteger(0)
-
-        self.assertEqual(0, i.value,
-                         self.bad_value.format('value', 0, i.value))
-        self.assertEqual(i.LENGTH, i.length,
-                         self.bad_value.format('length', i.LENGTH, i.length))
+        """
+        Test that a LongInteger can be instantiated.
+        """
+        long_int = primitives.LongInteger(1)
+        self.assertEqual(1, long_int.value)
 
     def test_init_unset(self):
-        i = primitives.LongInteger()
+        """
+        Test that a LongInteger can be instantiated with no input.
+        """
+        long_int = primitives.LongInteger()
+        self.assertEqual(0, long_int.value)
 
-        self.assertEqual(None, i.value,
-                         self.bad_value.format('value', None, i.value))
-        self.assertEqual(i.LENGTH, i.length,
-                         self.bad_value.format('length', i.LENGTH, i.length))
+    def test_init_on_max(self):
+        """
+        Test that a LongInteger can be instantiated with the maximum possible
+        signed 64-bit value.
+        """
+        primitives.LongInteger(primitives.LongInteger.MAX)
+
+    def test_init_on_min(self):
+        """
+        Test that a LongInteger can be instantiated with the minimum possible
+        signed 64-bit value.
+        """
+        primitives.LongInteger(primitives.LongInteger.MIN)
 
     def test_validate_on_valid(self):
-        i = primitives.LongInteger()
-        i.value = 0
-
-        # Check no exception thrown
-        i.validate()
-
-    def test_validate_on_valid_long(self):
-        i = primitives.LongInteger()
-        i.value = self.max_long + 1
-
-        # Check no exception thrown
-        i.validate()
+        """
+        Test that a LongInteger can be validated on good input.
+        """
+        long_int = primitives.LongInteger(1)
+        long_int.validate()
 
     def test_validate_on_valid_unset(self):
-        i = primitives.LongInteger()
-
-        # Check no exception thrown
-        i.validate()
+        """
+        Test that a LongInteger with no preset value can be validated.
+        """
+        long_int = primitives.LongInteger()
+        long_int.validate()
 
     def test_validate_on_invalid_type(self):
-        i = primitives.LongInteger()
-        i.value = 'test'
+        """
+        Test that a TypeError is thrown on input of invalid type (e.g., str).
+        """
+        self.assertRaises(TypeError, primitives.LongInteger, 'invalid')
 
-        self.assertRaises(errors.StateTypeError, i.validate)
+    def test_validate_on_invalid_value_too_big(self):
+        """
+        Test that a ValueError is thrown on input that is too large.
+        """
+        self.assertRaises(
+            ValueError, primitives.LongInteger, primitives.LongInteger.MAX + 1)
 
-    def test_validate_on_invalid_value(self):
-        self.assertRaises(errors.StateOverflowError, primitives.LongInteger,
-                          self.max_byte_long + 1)
+    def test_validate_on_invalid_value_too_small(self):
+        """
+        Test that a ValueError is thrown on input that is too small.
+        """
+        self.assertRaises(
+            ValueError, primitives.LongInteger, primitives.LongInteger.MIN - 1)
 
-    def test_read_value(self):
-        encoding = (b'\x00\x00\x00\x00\x00\x00\x00\x01')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
-        i.read_value(self.stream)
+    def test_read_zero(self):
+        """
+        Test that a LongInteger representing the value 0 can be read from a
+        byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00'
+            b'\x00')
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger()
+        long_int.read(stream)
+        self.assertEqual(0, long_int.value)
 
-        self.assertEqual(1, i.value, self.bad_read.format(1, i.value))
+    def test_read_max_max(self):
+        """
+        Test that a LongInteger representing the maximum positive value can be
+        read from a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x7f\xff\xff\xff\xff\xff\xff'
+            b'\xff')
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger()
+        long_int.read(stream)
+        self.assertEqual(primitives.LongInteger.MAX, long_int.value)
 
-    def test_read_value_zero(self):
-        encoding = (b'\x00\x00\x00\x00\x00\x00\x00\x00')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
-        i.read_value(self.stream)
-
-        self.assertEqual(0, i.value, self.bad_read.format(0, i.value))
-
-    def test_read_value_max_positive(self):
-        encoding = (b'\x7f\xff\xff\xff\xff\xff\xff\xff')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
-        i.read_value(self.stream)
-
-        self.assertEqual(self.max_long, i.value,
-                         self.bad_read.format(1, i.value))
-
-    def test_read_value_min_negative(self):
-        encoding = (b'\xff\xff\xff\xff\xff\xff\xff\xff')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
-        i.read_value(self.stream)
-
-        self.assertEqual(-1, i.value,
-                         self.bad_read.format(1, i.value))
-
-    def test_read(self):
+    def test_read_min_max(self):
+        """
+        Test that a LongInteger representing the minimum positive value can be
+        read from a byte stream.
+        """
         encoding = (
             b'\x42\x00\x00\x03\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00'
             b'\x01')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
-        i.read(self.stream)
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger()
+        long_int.read(stream)
+        self.assertEqual(1, long_int.value)
 
-        self.assertEqual(1, i.value, self.bad_read.format(1, i.value))
+    def test_read_max_min(self):
+        """
+        Test that a LongInteger representing the maximum negative value can be
+        read from a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\xff\xff\xff\xff\xff\xff\xff'
+            b'\xff')
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger()
+        long_int.read(stream)
+        self.assertEqual(-1, long_int.value)
+
+    def test_read_min_min(self):
+        """
+        Test that a LongInteger representing the minimum negative value can be
+        read from a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x80\x00\x00\x00\x00\x00\x00'
+            b'\x00')
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger(primitives.LongInteger.MIN)
+        long_int.read(stream)
+        self.assertEqual(primitives.LongInteger.MIN, long_int.value)
 
     def test_read_on_invalid_length(self):
+        """
+        Test that an InvalidPrimitiveLength exception is thrown when attempting
+        to decode a LongInteger with an invalid length.
+        """
         encoding = (
             b'\x42\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
             b'\x00')
-        self.stream = utils.BytearrayStream(encoding)
-        i = primitives.LongInteger()
+        stream = utils.BytearrayStream(encoding)
+        long_int = primitives.LongInteger()
 
-        self.assertRaises(errors.ReadValueError, i.read, self.stream)
+        self.assertRaises(
+            exceptions.InvalidPrimitiveLength, long_int.read, stream)
 
-    def test_write_value(self):
-        encoding = (b'\x00\x00\x00\x00\x00\x00\x00\x01')
-        i = primitives.LongInteger(1)
-        i.write_value(self.stream)
+    def test_write_zero(self):
+        """
+        Test that a LongInteger representing the value 0 can be written to a
+        byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00'
+            b'\x00')
+        stream = utils.BytearrayStream()
+        long_int = primitives.LongInteger(0)
+        long_int.write(stream)
 
-        result = self.stream.read()
-        len_exp = len(encoding)
-        len_rcv = len(result)
+        result = stream.read()
+        self.assertEqual(len(encoding), len(result))
+        self.assertEqual(encoding, result)
 
-        self.assertEqual(len_exp, len_rcv, self.bad_write.format(len_exp,
-                                                                 len_rcv))
-        self.assertEqual(encoding, result, self.bad_encoding)
+    def test_write_max_max(self):
+        """
+        Test that a LongInteger representing the maximum positive value can be
+        written to a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x7f\xff\xff\xff\xff\xff\xff'
+            b'\xff')
+        stream = utils.BytearrayStream()
+        long_int = primitives.LongInteger(primitives.LongInteger.MAX)
+        long_int.write(stream)
 
-    def test_write_value_zero(self):
-        encoding = (b'\x00\x00\x00\x00\x00\x00\x00\x00')
-        i = primitives.LongInteger(0)
-        i.write_value(self.stream)
+        result = stream.read()
+        self.assertEqual(len(encoding), len(result))
+        self.assertEqual(encoding, result)
 
-        result = self.stream.read()
-        len_exp = len(encoding)
-        len_rcv = len(result)
-
-        self.assertEqual(len_exp, len_rcv, self.bad_write.format(len_exp,
-                                                                 len_rcv))
-        self.assertEqual(encoding, result, self.bad_encoding)
-
-    def test_write_value_max_positive(self):
-        encoding = (b'\x7f\xff\xff\xff\xff\xff\xff\xff')
-        i = primitives.LongInteger(self.max_long)
-        i.write_value(self.stream)
-
-        result = self.stream.read()
-        len_exp = len(encoding)
-        len_rcv = len(result)
-
-        self.assertEqual(len_exp, len_rcv, self.bad_write.format(len_exp,
-                                                                 len_rcv))
-        self.assertEqual(encoding, result, self.bad_encoding)
-
-    def test_write_value_min_negative(self):
-        encoding = (b'\xff\xff\xff\xff\xff\xff\xff\xff')
-        i = primitives.LongInteger(-1)
-        i.write_value(self.stream)
-
-        result = self.stream.read()
-        len_exp = len(encoding)
-        len_rcv = len(result)
-
-        self.assertEqual(len_exp, len_rcv, self.bad_write.format(len_exp,
-                                                                 len_rcv))
-        self.assertEqual(encoding, result, self.bad_encoding)
-
-    def test_write(self):
+    def test_write_min_max(self):
+        """
+        Test that a LongInteger representing the minimum positive value can be
+        written to a byte stream.
+        """
         encoding = (
             b'\x42\x00\x00\x03\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00'
             b'\x01')
-        i = primitives.LongInteger(1)
-        i.write(self.stream)
+        stream = utils.BytearrayStream()
+        long_int = primitives.LongInteger(1)
+        long_int.write(stream)
 
-        result = self.stream.read()
-        len_exp = len(encoding)
-        len_rcv = len(result)
+        result = stream.read()
+        self.assertEqual(len(encoding), len(result))
+        self.assertEqual(encoding, result)
 
-        self.assertEqual(len_exp, len_rcv, self.bad_write.format(len_exp,
-                                                                 len_rcv))
-        self.assertEqual(encoding, result, self.bad_encoding)
+    def test_write_max_min(self):
+        """
+        Test that a LongInteger representing the maximum negative value can be
+        written to a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\xff\xff\xff\xff\xff\xff\xff'
+            b'\xff')
+        stream = utils.BytearrayStream()
+        long_int = primitives.LongInteger(-1)
+        long_int.write(stream)
+
+        result = stream.read()
+        self.assertEqual(len(encoding), len(result))
+        self.assertEqual(encoding, result)
+
+    def test_write_min_min(self):
+        """
+        Test that a LongInteger representing the minimum negative value can be
+        written to a byte stream.
+        """
+        encoding = (
+            b'\x42\x00\x00\x03\x00\x00\x00\x08\x80\x00\x00\x00\x00\x00\x00'
+            b'\x00')
+        stream = utils.BytearrayStream()
+        long_int = primitives.LongInteger(primitives.LongInteger.MIN)
+        long_int.write(stream)
+
+        result = stream.read()
+        self.assertEqual(len(encoding), len(result))
+        self.assertEqual(encoding, result)
+
+    def test_repr(self):
+        """
+        Test that the representation of a LongInteger is formatted properly.
+        """
+        long_int = primitives.LongInteger()
+        value = "value={0}".format(long_int.value)
+        tag = "tag={0}".format(long_int.tag)
+        self.assertEqual(
+            "LongInteger({0}, {1})".format(value, tag), repr(long_int))
+
+    def test_str(self):
+        """
+        Test that the string representation of a LongInteger is formatted
+        properly.
+        """
+        self.assertEqual("0", str(primitives.LongInteger()))
+
+    def test_equal_on_equal(self):
+        """
+        Test that the equality operator returns True when comparing two
+        LongIntegers.
+        """
+        a = primitives.LongInteger(1)
+        b = primitives.LongInteger(1)
+
+        self.assertTrue(a == b)
+        self.assertTrue(b == a)
+
+    def test_equal_on_equal_and_empty(self):
+        """
+        Test that the equality operator returns True when comparing two
+        LongIntegers.
+        """
+        a = primitives.LongInteger()
+        b = primitives.LongInteger()
+
+        self.assertTrue(a == b)
+        self.assertTrue(b == a)
+
+    def test_equal_on_not_equal(self):
+        """
+        Test that the equality operator returns False when comparing two
+        LongIntegers with different values.
+        """
+        a = primitives.LongInteger(1)
+        b = primitives.LongInteger(2)
+
+        self.assertFalse(a == b)
+        self.assertFalse(b == a)
+
+    def test_equal_on_type_mismatch(self):
+        """
+        Test that the equality operator returns False when comparing a
+        LongInteger to a non-LongInteger object.
+        """
+        a = primitives.LongInteger()
+        b = 'invalid'
+
+        self.assertFalse(a == b)
+        self.assertFalse(b == a)
+
+    def test_not_equal_on_equal(self):
+        """
+        Test that the inequality operator returns False when comparing
+        two LongIntegers with the same values.
+        """
+        a = primitives.LongInteger(1)
+        b = primitives.LongInteger(1)
+
+        self.assertFalse(a != b)
+        self.assertFalse(b != a)
+
+    def test_not_equal_on_equal_and_empty(self):
+        """
+        Test that the inequality operator returns False when comparing
+        two LongIntegers.
+        """
+        a = primitives.LongInteger()
+        b = primitives.LongInteger()
+
+        self.assertFalse(a != b)
+        self.assertFalse(b != a)
+
+    def test_not_equal_on_not_equal(self):
+        """
+        Test that the inequality operator returns True when comparing two
+        LongIntegers with different values.
+        """
+        a = primitives.LongInteger(1)
+        b = primitives.LongInteger(2)
+
+        self.assertTrue(a != b)
+        self.assertTrue(b != a)
+
+    def test_not_equal_on_type_mismatch(self):
+        """
+        Test that the inequality operator returns True when comparing a
+        LongInteger to a non-LongInteger object.
+        """
+        a = primitives.LongInteger()
+        b = 'invalid'
+
+        self.assertTrue(a != b)
+        self.assertTrue(b != a)