crypto: add already solved challenges

crypto/waves_over_lambda/solve.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python -p python3
+
+# NOTE: the colors are used to keep track of which letters have been
+#       already substituted, and which are still unknown.
+
+def green(s):
+    return f"\033[42m{s}\033[0m"
+
+def red(s):
+    return f"\033[41m{s}\033[0m"
+
+def substitute(cipher_text, substitution_map):
+    for letter in cipher_text:
+        if letter in substitution_map:
+            print(green(substitution_map[letter]), end="")
+        else:
+            print(red(letter), end="")
+
+with open('ciphertext', 'r') as file:
+    enc = file.read()
+
+# Here, I will be slowly substituting the letters in the ciphertext
+# based on what I believe the words to be. I have commented out the
+# invocations of substitute, and commented the newly found letters
+# after each invocation.
+
+# Starting off, "csds bh reod kzim" looks like "here is your flag"
+
+substitution_map = {
+    '-': '-',
+    '_': '_',
+    '\n': '\n',
+    ' ': ' ',
+    ',': ',',
+    '.': '.',
+    ';': ';',
+    'c': 'h',
+    's': 'e',
+    'd': 'r',
+    'b': 'i',
+    'h': 's',
+    'r': 'y',
+    'e': 'o',
+    'o': 'u',
+    'k': 'f',
+    'z': 'l',
+    'i': 'a',
+    'm': 'g',
+}
+
+# substitute(enc, substitution_map)
+
+# found:   euro't'e, ligh'a', o'f'er, 'q'ri'a'ish
+# suspect: euro p e, ligh t,  o v er,  b ri t ish
+
+substitution_map['t'] = 'p'
+substitution_map['a'] = 't'
+substitution_map['f'] = 'v'
+substitution_map['q'] = 'b'
+
+# substitute(enc, substitution_map)
+
+# found:   visite'n', british 'y'useu'y', sear'p'h, havi'x'g
+# suspect: visite d , british  m useu m , sear c h, havi'n'g
+
+substitution_map['n'] = 'd'
+substitution_map['y'] = 'm'
+substitution_map['p'] = 'c'
+substitution_map['x'] = 'n'
+
+# substitute(enc, substitution_map)
+
+# found:   fre'g'uency, 'l'no'w'n, 'j'ust, e'v'act
+# suspect: fre q uency,  k no w n,  j ust, e'x'act
+
+substitution_map['g'] = 'q'
+substitution_map['l'] = 'k'
+substitution_map['w'] = 'w'
+substitution_map['j'] = 'j'
+substitution_map['v'] = 'x'
+
+substitute(enc, substitution_map)
+
+# still not sure about 'u'? But flag is found