diff --git a/src/utils.py b/src/utils.py
index 22d21a5..038e914 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -1,25 +1,83 @@
 import secrets
 
 
-def random_number_in_range(min_val: int, max_val: int) -> int:
-    """ originally secure_rand """
-    return min_val + secrets.randbelow(max_val - min_val + 1)
+def secure_fisher_yates_shuffle(arr: list) -> list:
+    n = len(arr)
+    for i in range(n - 1, 0, -1):
+        j = secrets.randbelow(i + 1)
+        arr[i], arr[j] = arr[j], arr[i]
+    return arr
 
 
-def random_number_in_range_excluding(min_val: int, max_val: int, exclude: list[int]) -> int:
-    """ originally secure_rand """
-
-    return min_val + secrets.randbelow(max_val - min_val + 1)
+def generate_random_nonrepeating_list(list_len: int, min_val: int = 0, max_val: int = 2 ** 16) -> list[int]:
+    assert(max_val-min_val >= list_len)
+    return secure_fisher_yates_shuffle(list(range(min_val, max_val))[:list_len])
 
 
-def generate_random_list(list_len: int, min_val: int = 0, max_val: int = 255) -> list[int]:
-    return [random_number_in_range(min_val, max_val) for _ in range(list_len)]
-
-
-def generate_random_matrix(rows: int, cols: int, min_val: int = 0, max_val: int = 255) -> list[list[int]]:
-    return [[random_number_in_range(min_val, max_val) for _ in range(rows)] for _ in range(cols)]
+def generate_random_nonrepeating_matrix(rows: int, cols: int, min_val: int = 0, max_val: int = 2 ** 16) -> list[list[int]]:
+    values = generate_random_nonrepeating_list(rows*cols, min_val, max_val)
+    matrix = []
+    idx = 0
+    for _ in range(cols):
+        row = []
+        for _ in range(rows):
+            row.append(values[idx])
+            idx += 1
+        matrix.append(row)
+    return matrix
 
 
 def xor_lists(l1: list[int], l2: list[int]):
     assert len(l1) == len(l2)
     return [l2[i] ^ l1[i] for i in range(len(l1))]
+
+
+def generate_random_index_interface(height: int, width: int) -> list[list[int]]:
+    interface = []
+    idx = 0
+    for i in range(height):
+        key = []
+        for j in range(width):
+            key.append(idx)
+            idx += 1
+        key = secure_fisher_yates_shuffle(key)
+        interface.append(key)
+    return interface
+
+
+def generate_serialized_index_interface(height: int, width: int) -> list[list[int]]:
+    interface = []
+    idx = 0
+    for i in range(height):
+        key = []
+        for j in range(width):
+            key.append(idx)
+            idx += 1
+        interface.append(key)
+    return interface
+
+
+def interface_transpose(interface: list[list[int]]) -> list[list[int]]:
+    return [list(row) for row in zip(*interface)]
+
+
+def shuffle_interface(self):
+    pass
+
+
+def disperse_interface(user_interface: list[list[int]]):
+    shuffled_keys = secure_fisher_yates_shuffle(user_interface)
+    dispersed_interface = random_attribute_rotation(shuffled_keys)
+    return dispersed_interface
+
+
+def random_attribute_rotation(user_interface: list[list[int]]) -> list[list[int]]:
+    numb_attr = len(user_interface[0])
+    numb_keys = len(user_interface)
+    attr_rotation = secure_fisher_yates_shuffle(list(range(numb_keys)))[:numb_attr]
+    transposed_user_interface = interface_transpose(user_interface)
+    assert (len(attr_rotation) == len(transposed_user_interface))
+    for idx, attr_set in enumerate(transposed_user_interface):
+        rotation = attr_rotation[idx]
+        transposed_user_interface[idx] = attr_set[rotation:] + attr_set[:rotation]
+    return interface_transpose(transposed_user_interface)