New Caesar

new_ceasar/new_caesar.py

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+import string
+
+LOWERCASE_OFFSET = ord("a")
+ALPHABET = string.ascii_lowercase[:16]
+
+def b16_encode(plain):
+	enc = ""
+	for c in plain:
+		binary = "{0:08b}".format(ord(c))
+		enc += ALPHABET[int(binary[:4], 2)]
+		enc += ALPHABET[int(binary[4:], 2)]
+	return enc
+
+def shift(c, k):
+	t1 = ord(c) - LOWERCASE_OFFSET
+	t2 = ord(k) - LOWERCASE_OFFSET
+	return ALPHABET[(t1 + t2) % len(ALPHABET)]
+
+flag = "redacted"
+key = "redacted"
+assert all([k in ALPHABET for k in key])
+assert len(key) == 1
+
+b16 = b16_encode(flag)
+enc = ""
+for i, c in enumerate(b16):
+	enc += shift(c, key[i % len(key)])
+print(enc)