Update app.py

app.py

@@ -8,35 +8,36 @@ import random
 import base64
 
 # 1. Quantum Key Distribution (BB84 Protocol)
-def generate_qkd_key(length=256):  # default length increased for Fernet compatibility
-    alice_bits = [random.randint(0, 1) for _ in range(length)]
-    alice_bases = [random.randint(0, 1) for _ in range(length)]
-    bob_bases = [random.randint(0, 1) for _ in range(length)]
-
+def generate_qkd_key(length=128):
     shared_key = ""
-    for i in range(length):
-        if alice_bases[i] == bob_bases[i]:
-            shared_key += str(alice_bits[i])
+    while len(shared_key) < length:
+        alice_bit = random.randint(0, 1)
+        alice_basis = random.randint(0, 1)
+        bob_basis = random.randint(0, 1)
+        if alice_basis == bob_basis:
+            shared_key += str(alice_bit)
     return shared_key
 
 # 2. Convert QKD binary key to 32-byte Fernet-compatible key
 def bb84_to_fernet_key(qkey_binary_str):
-    padded = qkey_binary_str.ljust(256, '0')[:256]  # force exactly 256 bits
-    int_val = int(padded, 2)
+    if len(qkey_binary_str) < 256:
+        raise ValueError("QKD key must be at least 256 bits to generate Fernet key.")
+
+    binary_256 = qkey_binary_str[:256]
+    int_val = int(binary_256, 2)
     byte_val = int_val.to_bytes(32, 'big')  # 256 bits = 32 bytes
     fernet_key = base64.urlsafe_b64encode(byte_val)
 
-    # ✅ Validate length
     if len(fernet_key) != 44:
         raise ValueError("Generated Fernet key is not 32 url-safe base64-encoded bytes")
 
-    print("✅ Final Fernet key:", fernet_key.decode(), "Length:", len(fernet_key))
     return fernet_key
 
 # 3. Encrypt message using QKD key
 def quantum_encrypt(message, qkd_key):
-    if not qkd_key or len(qkd_key) < 64:
-        return "❌ QKD key not generated or too short", ""
+    if not qkd_key or len(qkd_key) < 72:
+        return "❌ QKD key too short. Minimum usable bits: 72", ""
+
     try:
         fernet_key = bb84_to_fernet_key(qkd_key)
         f = Fernet(fernet_key)
@@ -72,7 +73,7 @@ def quantum_intrusion_detection(data_stream):
     except:
         return "❌ Invalid input. Please enter two comma-separated numbers like 0.3,0.7"
 
-# 6. Quantum Random Number Generator using backend.run()
+# 6. Quantum Random Number Generator
 def quantum_random_number():
     backend = Aer.get_backend('aer_simulator')
     circuit = QuantumCircuit(1, 1)
@@ -93,7 +94,7 @@ def create_interface():
 
         # Tab 1: QKD Key Generation
         with gr.Tab("1️⃣ Quantum Key Distribution"):
-            key_length = gr.Slider(minimum=32, maximum=128, step=8, value=128, label="Select Key Length (min 72 bits)")
+            key_length = gr.Slider(minimum=72, maximum=512, step=8, value=128, label="Select QKD Key Length (≥ 72 bits)")
             qkd_btn = gr.Button("Generate Quantum Key")
             qkd_output = gr.Textbox(label="Generated QKD Key")