diff --git a/DIRECTORY.md b/DIRECTORY.md
index 1e0e450bca2b..d25d665ef28b 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -29,6 +29,7 @@
   * [Minmax](backtracking/minmax.py)
   * [N Queens](backtracking/n_queens.py)
   * [N Queens Math](backtracking/n_queens_math.py)
+  * [Power Sum](backtracking/power_sum.py)
   * [Rat In Maze](backtracking/rat_in_maze.py)
   * [Sudoku](backtracking/sudoku.py)
   * [Sum Of Subsets](backtracking/sum_of_subsets.py)
diff --git a/quantum/bb84.py b/quantum/bb84.py
index e90a11c2aef3..e0b888ee7f50 100644
--- a/quantum/bb84.py
+++ b/quantum/bb84.py
@@ -68,6 +68,11 @@ def bb84(key_len: int = 8, seed: int | None = None) -> str:
 
     >>> bb84(8, seed=0)
     '10110001'
+
+    # Example from
+    # https://learn.qiskit.org/course/ch-algorithms/quantum-key-distribution
+    >>> bb84(100, seed=0)
+    '011110100001000111010110100000010011000111100100'
     """
     # Set up the random number generator.
     rng = np.random.default_rng(seed=seed)
@@ -127,7 +132,4 @@ def bb84(key_len: int = 8, seed: int | None = None) -> str:
 
 
 if __name__ == "__main__":
-    print(f"The generated key is : {bb84(8, seed=0)}")
-    from doctest import testmod
-
-    testmod()
+    print(bb84(100, seed=0))