diff --git a/tensorizer/serialization.py b/tensorizer/serialization.py
index 9a1b2e6..b88f483 100644
--- a/tensorizer/serialization.py
+++ b/tensorizer/serialization.py
@@ -170,7 +170,7 @@ class TensorType(IntEnum):
 
 # The hashable_segment_views used to include the fields that include the hash results themselves.
 # These fields were zero when computing hash
-HEADER_HASHES_OMIT_HASH_FIELDS = 5
+HEADER_HASHES_OMIT_HASH_FIELDS_TENSORIZER_VERSION = 5
 
 # To serialize meta tensors into metadata-only tensors
 # that deserialize back into zeroed-out buffers, data version 4 is required.
@@ -702,7 +702,10 @@ def __init__(
                 self.crypt_info = _crypt_info.CryptInfo.unpack_from(
                     crypt_info_slice
                 )
-            if self.file_version < HEADER_HASHES_OMIT_HASH_FIELDS:
+            if (
+                self.file_version
+                < HEADER_HASHES_OMIT_HASH_FIELDS_TENSORIZER_VERSION
+            ):
                 self._hashable_segments = (
                     slice(None, crypt_info_start),
                     slice(offset, None),
@@ -715,7 +718,10 @@ def __init__(
         self.data_length = self.data_length_segment.unpack_from(buffer, offset)[
             0
         ]
-        if self.file_version < HEADER_HASHES_OMIT_HASH_FIELDS:
+        if (
+            self.file_version
+            < HEADER_HASHES_OMIT_HASH_FIELDS_TENSORIZER_VERSION
+        ):
             if not check_crypt_info:
                 self._hashable_segments = (slice(None, None),)
         else:
@@ -1730,7 +1736,7 @@ def __init__(
                         check_crypt_info=self._has_crypt_info,
                     )
                     if header is None:
-                        raise KeyError("Unexpected empty header")
+                        raise ValueError("Unexpected empty header")
                     self._headers[entry.name] = header
             else:
                 self._headers = None
@@ -3804,7 +3810,7 @@ def __init__(
             self.name = _TensorPath.wrap_(name)
             self.dtype: Optional[str] = None  # _prepare_for_write_dtype
             self.shape = tensor.size()
-            self.data_length = tensor.nbytes
+            self.data_length = tensor.element_size() * tensor.nelement()
             # self.file_offset  # intentionally omitted, handled by _write_headers()
             self.include_crc32 = True
             self.include_sha256 = True
@@ -3814,11 +3820,11 @@ def __init__(
 
             # Additional payloads that get set and used during the prepare_for_write procedures
             self.header: Optional[_TensorHeaderSerializer] = (
-                None  # $et in _prepare_for_write_headers
+                None  # Set in _prepare_for_write_headers
             )
             self.metadata_pos = -1  # Set in _prepare_for_write_headers
             self.encryptor: Optional[_crypt.ChunkedEncryption] = (
-                None  # $et in _do_encryption if encrypted
+                None  # Set in _do_encryption if encrypted
             )
 
             # self.tensor_data_task is a future for processing some contents of self.tensor
@@ -3828,6 +3834,12 @@ def __init__(
 
         @property
         def tensor_memoryview(self) -> memoryview:
+            if not self.tensor.is_contiguous():
+                # This is actually possible, but probably not intended here,
+                # so throw an error instead of handling this case
+                raise BufferError(
+                    "Cannot create a memoryview of a discontiguous tensor"
+                )
             nbytes = self.tensor.element_size() * self.tensor.nelement()
             return memoryview(
                 (ctypes.c_char * nbytes).from_address(self.tensor.data_ptr())
@@ -4198,7 +4210,9 @@ def make_contiguous(write_spec, dependency):
             if dependency is not None:
                 dependency.result(_TIMEOUT)
             write_spec.tensor = write_spec.tensor.contiguous()
-            write_spec.data_length = write_spec.tensor.nbytes
+            write_spec.data_length = (
+                write_spec.tensor.element_size() * write_spec.tensor.nelement()
+            )
             write_spec.user_owns_tensor_data = False
 
         for w in write_specs:
@@ -4218,10 +4232,9 @@ def _prepare_for_write_dtype(self, write_specs: Sequence[_WriteSpec]):
                 # is opaque
                 w.dtype = (
                     f"<V{w.tensor.element_size():d}"
-                    + OPAQUE_DTYPE_SEP
-                    + tensor_dtype_str
+                    f"{OPAQUE_DTYPE_SEP}"
+                    f"{tensor_dtype_str}"
                 )
-                w.set_min_file_version_number(OPAQUE_TENSORIZER_VERSION)
             else:
                 w.dtype = torch_dtype_to_numpy_dtype_cache.get(
                     tensor_dtype_str, None
@@ -4245,7 +4258,11 @@ def _do_clone(write_spec, dependency: Optional[_Future]):
     def _prepare_for_write_encryption(
         self, write_specs: Sequence[_WriteSpec]
     ) -> None:
-        assert self._encrypted and self._encryption is not None
+        if not self._encrypted or self._encryption is None:
+            raise RuntimeError(
+                "Tried to encrypt tensors without encryption parameters"
+                " having been provided"
+            )
 
         # If any tensors are shared, so we need to clone all but one of them before encrypting
         write_specs_by_addr: Dict[int, List[TensorSerializer._WriteSpec]] = (
@@ -4270,7 +4287,7 @@ def _prepare_for_write_encryption(
             )
 
             clone_tasks: List[_Future] = []
-            for w in shared_write_specs[1:]:
+            for w in shared_write_specs[:-1]:
                 clone_tasks.append(
                     self._computation_pool.submit(
                         self._do_clone, w, clone_dependencies
@@ -4278,10 +4295,10 @@ def _prepare_for_write_encryption(
                 )
                 w.user_owns_tensor_data = False
 
-            shared_write_specs[0].tensor_data_task = _FutureGroup(
+            shared_write_specs[-1].tensor_data_task = _FutureGroup(
                 clone_tasks + clone_dependencies.futures
             )
-            for w in shared_write_specs[1:]:
+            for w in shared_write_specs[:-1]:
                 w.tensor_data_task = _FutureGroup(clone_tasks)
 
         for w in write_specs:
@@ -4340,7 +4357,7 @@ def _prepare_for_write_headers(
                 dtype_bytes,
                 w.shape,
                 w.data_length,
-                0,  # bogus file_offset. This gets filled in in build()
+                0,  # placeholder file_offset
                 include_crc32=w.include_crc32,
                 include_sha256=w.include_sha256,
                 crypt_info=w.crypt_info,