Add lab3

lab3/zad1.py

@@ -0,0 +1,62 @@
+from copy import copy
+
+def zad1():
+    def a(index, start: list[int]):
+        if index < 4:
+            return start[index]
+        else:
+            temp = copy(start)
+            for i in range(0, index):
+                temp[i % 4] = (temp[(i % 4) - 4] + temp[(i % 4) - 3] + temp[(i % 4) - 2] + temp[(i % 4) - 1]) % 2
+            return temp[index % 4]
+
+    def b(index, start: list[int]):
+        if index < 4:
+            return start[index]
+        else:
+            temp = copy(start)
+            for i in range(0, index):
+                temp[i % 4] = (temp[(i % 4) - 4] + temp[(i % 4) - 1]) % 2
+            return temp[index % 4]
+
+
+    def generate(func, start: list[int], length = 50):
+        return ''.join([chr(func(i, start) + ord('0')) for i in range(0, length)])
+
+    print(f"Dane testowe:")
+
+    print(f"a - wektor: 0100")
+    print(f"a - strumien: {generate(a, [0, 1, 0, 0])}")
+    print(f"b - wektor: 1000")
+    print(f"b - strumien: {generate(b, [1, 0, 0, 0])}")
+
+    def search(seq):
+        guess = 1
+        max_len = len(seq)
+        for x in range(1, max_len):
+            for y in range(1, max_len):
+                if seq[0:x] == seq[y:y+x] :
+                    guess = x
+
+        return abs(guess - max_len)
+
+
+    print(f"\nWyniki a:")
+    for i in range(0, 16):
+        binary = [ord(c) - ord('0') for c in f"{i:04b}"]
+        stream = generate(a, binary)
+        print(f"P({i:04b})={search(stream)}")
+
+
+    print(f"\nWyniki b:")
+    for i in range(0, 16):
+        binary = [ord(c) - ord('0') for c in f"{i:04b}"]
+        stream = generate(b, binary)
+        print(f"P({i:04b})={search(stream)}")
+
+
+def main():
+    zad1()
+
+if __name__ == '__main__':
+    main()

lab3/zad2.py

@@ -0,0 +1,46 @@
+from copy import copy
+
+def zad2():
+    def gen(index, start: list[int]):
+        if index < 5:
+            return start[index]
+        else:
+            temp = copy(start)
+            for i in range(0, index):
+                temp[i % 5] = (temp[(i % 5) - 5] + temp[(i % 5) - 2]) % 2
+            return temp[index % 5]
+
+
+    def generate(start: list[int], length = 50):
+        return ''.join([chr(gen(i, start) + ord('0')) for i in range(0, length)])
+
+    plaintext_str = "011001111111000"
+    plaintext = [ord(c) - ord('0') for c in plaintext_str]
+
+    stream = generate([1, 1, 0, 1, 0], length=15)
+
+    def encode(plaintext, stream):
+        return ''.join([chr(((ord(p) + ord(k)) % 2) + ord('0')) for p, k in zip(plaintext, stream)])
+
+    print(f"Encryption:")
+    print(f"Plaintext: {plaintext_str}")
+    print(f"Key stream:{stream}")
+    encoded = encode(plaintext_str, stream)
+    print(f"Cyphertext:{encoded}")
+
+    def decode(plaintext, stream):
+        return ''.join([chr(((ord(p) - ord(k)) % 2) + ord('0')) for p, k in zip(plaintext, stream)])
+
+    print("Decryption:")
+    print(f"Cyphertext:{encoded}")
+    print(f"Key stream:{stream}")
+    decoded = decode(encoded, stream)
+    print(f"Plaintext: {decoded}")
+
+
+
+def main():
+    zad2()
+
+if __name__ == '__main__':
+    main()

lab3/zad3.py

@@ -0,0 +1,72 @@
+import matplotlib.pyplot as plt
+
+
+def zad3():
+    def parity(y_i) -> int:
+        parity = 0
+        while True:
+            parity += y_i & 1
+            y_i = y_i >> 1
+            if not y_i:
+                break
+        return parity % 2
+
+
+    def blumblumshub(p, q, s):
+        n = p * q
+        y = []
+        z = ""
+        for i in range(0, n):
+            y_im1 = s if i == 0 else y[i-1]
+            y_i = ((y_im1*y_im1) % n)
+            y.append(y_i)
+
+            z_i = parity(y_i)
+            z += chr(z_i + ord('0'))
+
+        plt.title(f"{p=}, {q=}, {s=}")
+        plt.yscale("log")
+        plt.plot(y, 'o-', linewidth=0.1, markersize=0.3)
+        plt.show()
+
+        return z[1::]
+
+    def search(seq):
+        max_len = len(seq) // 2
+        for length in range(1, max_len):
+            for y in range(0, max_len, length):
+                if len(seq[y:y+length]) < length:
+                    break
+                if seq[0:length] != seq[y:y+length]:
+                    break
+            else:
+                return length
+
+        return 0
+
+
+
+    print("a: ")
+    a = blumblumshub(7, 19, 100)
+    print(f"{a}")
+    a_cycle = search(a)
+    print(f"{a_cycle=}")
+
+    print("v: ")
+    b = blumblumshub(67, 71, 100)
+    print(f"{b}")
+    b_cycle = search(b)
+    print(f"{b_cycle=}")
+
+    print("v: ")
+    c = blumblumshub(163, 167, 100)
+    print(f"{c}")
+    c_cycle = search(c)
+    print(f"{c_cycle=}")
+
+
+def main():
+    zad3()
+
+if __name__ == '__main__':
+    main()