docs/szyfrow/autokey.html

   1 <!doctype html>
   2 <html lang="en">
   3 <head>
   4 <meta charset="utf-8">
   5 <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1" />
   6 <meta name="generator" content="pdoc 0.9.2" />
   7 <title>szyfrow.autokey API documentation</title>
   8 <meta name="description" content="Enciphering and deciphering using the [Autokey cipher](https://en.wikipedia.org/wiki/Autokey_cipher).
   9 Also attempts to break messages that use a …" />
  10 <link rel="preload stylesheet" as="style" href="https://cdnjs.cloudflare.com/ajax/libs/10up-sanitize.css/11.0.1/sanitize.min.css" integrity="sha256-PK9q560IAAa6WVRRh76LtCaI8pjTJ2z11v0miyNNjrs=" crossorigin>
  11 <link rel="preload stylesheet" as="style" href="https://cdnjs.cloudflare.com/ajax/libs/10up-sanitize.css/11.0.1/typography.min.css" integrity="sha256-7l/o7C8jubJiy74VsKTidCy1yBkRtiUGbVkYBylBqUg=" crossorigin>
  12 <link rel="stylesheet preload" as="style" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.1.1/styles/github.min.css" crossorigin>
  13 <style>:root{--highlight-color:#fe9}.flex{display:flex !important}body{line-height:1.5em}#content{padding:20px}#sidebar{padding:30px;overflow:hidden}#sidebar > *:last-child{margin-bottom:2cm}.http-server-breadcrumbs{font-size:130%;margin:0 0 15px 0}#footer{font-size:.75em;padding:5px 30px;border-top:1px solid #ddd;text-align:right}#footer p{margin:0 0 0 1em;display:inline-block}#footer p:last-child{margin-right:30px}h1,h2,h3,h4,h5{font-weight:300}h1{font-size:2.5em;line-height:1.1em}h2{font-size:1.75em;margin:1em 0 .50em 0}h3{font-size:1.4em;margin:25px 0 10px 0}h4{margin:0;font-size:105%}h1:target,h2:target,h3:target,h4:target,h5:target,h6:target{background:var(--highlight-color);padding:.2em 0}a{color:#058;text-decoration:none;transition:color .3s ease-in-out}a:hover{color:#e82}.title code{font-weight:bold}h2[id^="header-"]{margin-top:2em}.ident{color:#900}pre code{background:#f8f8f8;font-size:.8em;line-height:1.4em}code{background:#f2f2f1;padding:1px 4px;overflow-wrap:break-word}h1 code{background:transparent}pre{background:#f8f8f8;border:0;border-top:1px solid #ccc;border-bottom:1px solid #ccc;margin:1em 0;padding:1ex}#http-server-module-list{display:flex;flex-flow:column}#http-server-module-list div{display:flex}#http-server-module-list dt{min-width:10%}#http-server-module-list p{margin-top:0}.toc ul,#index{list-style-type:none;margin:0;padding:0}#index code{background:transparent}#index h3{border-bottom:1px solid #ddd}#index ul{padding:0}#index h4{margin-top:.6em;font-weight:bold}@media (min-width:200ex){#index .two-column{column-count:2}}@media (min-width:300ex){#index .two-column{column-count:3}}dl{margin-bottom:2em}dl dl:last-child{margin-bottom:4em}dd{margin:0 0 1em 3em}#header-classes + dl > dd{margin-bottom:3em}dd dd{margin-left:2em}dd p{margin:10px 0}.name{background:#eee;font-weight:bold;font-size:.85em;padding:5px 10px;display:inline-block;min-width:40%}.name:hover{background:#e0e0e0}dt:target .name{background:var(--highlight-color)}.name > span:first-child{white-space:nowrap}.name.class > span:nth-child(2){margin-left:.4em}.inherited{color:#999;border-left:5px solid #eee;padding-left:1em}.inheritance em{font-style:normal;font-weight:bold}.desc h2{font-weight:400;font-size:1.25em}.desc h3{font-size:1em}.desc dt code{background:inherit}.source summary,.git-link-div{color:#666;text-align:right;font-weight:400;font-size:.8em;text-transform:uppercase}.source summary > *{white-space:nowrap;cursor:pointer}.git-link{color:inherit;margin-left:1em}.source pre{max-height:500px;overflow:auto;margin:0}.source pre code{font-size:12px;overflow:visible}.hlist{list-style:none}.hlist li{display:inline}.hlist li:after{content:',\2002'}.hlist li:last-child:after{content:none}.hlist .hlist{display:inline;padding-left:1em}img{max-width:100%}td{padding:0 .5em}.admonition{padding:.1em .5em;margin-bottom:1em}.admonition-title{font-weight:bold}.admonition.note,.admonition.info,.admonition.important{background:#aef}.admonition.todo,.admonition.versionadded,.admonition.tip,.admonition.hint{background:#dfd}.admonition.warning,.admonition.versionchanged,.admonition.deprecated{background:#fd4}.admonition.error,.admonition.danger,.admonition.caution{background:lightpink}</style>
  14 <style media="screen and (min-width: 700px)">@media screen and (min-width:700px){#sidebar{width:30%;height:100vh;overflow:auto;position:sticky;top:0}#content{width:70%;max-width:100ch;padding:3em 4em;border-left:1px solid #ddd}pre code{font-size:1em}.item .name{font-size:1em}main{display:flex;flex-direction:row-reverse;justify-content:flex-end}.toc ul ul,#index ul{padding-left:1.5em}.toc > ul > li{margin-top:.5em}}</style>
  15 <style media="print">@media print{#sidebar h1{page-break-before:always}.source{display:none}}@media print{*{background:transparent !important;color:#000 !important;box-shadow:none !important;text-shadow:none !important}a[href]:after{content:" (" attr(href) ")";font-size:90%}a[href][title]:after{content:none}abbr[title]:after{content:" (" attr(title) ")"}.ir a:after,a[href^="javascript:"]:after,a[href^="#"]:after{content:""}pre,blockquote{border:1px solid #999;page-break-inside:avoid}thead{display:table-header-group}tr,img{page-break-inside:avoid}img{max-width:100% !important}@page{margin:0.5cm}p,h2,h3{orphans:3;widows:3}h1,h2,h3,h4,h5,h6{page-break-after:avoid}}</style>
  16 <script defer src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.1.1/highlight.min.js" integrity="sha256-Uv3H6lx7dJmRfRvH8TH6kJD1TSK1aFcwgx+mdg3epi8=" crossorigin></script>
  17 <script>window.addEventListener('DOMContentLoaded', () => hljs.initHighlighting())</script>
  18 </head>
  19 <body>
  20 <main>
  21 <article id="content">
  22 <header>
  23 <h1 class="title">Module <code>szyfrow.autokey</code></h1>
  24 </header>
  25 <section id="section-intro">
  26 <p>Enciphering and deciphering using the <a href="https://en.wikipedia.org/wiki/Autokey_cipher">Autokey cipher</a>.
  27 Also attempts to break messages that use a Autokey cipher.</p>
  28 <details class="source">
  29 <summary>
  30 <span>Expand source code</span>
  31 </summary>
  32 <pre><code class="python">&#34;&#34;&#34;Enciphering and deciphering using the [Autokey cipher](https://en.wikipedia.org/wiki/Autokey_cipher).
  33 Also attempts to break messages that use a Autokey cipher.
  34 &#34;&#34;&#34;
  35 import math
  36 import multiprocessing
  37 from szyfrow.support.utilities import *
  38 from szyfrow.support.language_models import *
  39 from szyfrow.caesar import caesar_encipher_letter, caesar_decipher_letter
  40
  41
  42 def autokey_encipher(message, keyword):
  43     &#34;&#34;&#34;Encipher with the autokey cipher
  44
  45     &gt;&gt;&gt; autokey_encipher(&#39;meetatthefountain&#39;, &#39;kilt&#39;)
  46     &#39;wmpmmxxaeyhbryoca&#39;
  47     &#34;&#34;&#34;
  48     shifts = [pos(l) for l in keyword + message]
  49     pairs = zip(message, shifts)
  50     return cat([caesar_encipher_letter(l, k) for l, k in pairs])
  51
  52 def autokey_decipher(ciphertext, keyword):
  53     &#34;&#34;&#34;Decipher with the autokey cipher
  54
  55     &gt;&gt;&gt; autokey_decipher(&#39;wmpmmxxaeyhbryoca&#39;, &#39;kilt&#39;)
  56     &#39;meetatthefountain&#39;
  57     &#34;&#34;&#34;
  58     plaintext = []
  59     keys = list(keyword)
  60     for c in ciphertext:
  61         plaintext_letter = caesar_decipher_letter(c, pos(keys[0]))
  62         plaintext += [plaintext_letter]
  63         keys = keys[1:] + [plaintext_letter]
  64     return cat(plaintext)
  65
  66
  67 def autokey_sa_break( message
  68                     , min_keylength=2
  69                     , max_keylength=20
  70                     , workers=10
  71                     , initial_temperature=200
  72                     , max_iterations=20000
  73                     , fitness=Pletters
  74                     , chunksize=1
  75                     , result_count=1
  76                     ):
  77     &#34;&#34;&#34;Break an autokey cipher by simulated annealing
  78     &#34;&#34;&#34;
  79     worker_args = []
  80     ciphertext = sanitise(message)
  81     for keylength in range(min_keylength, max_keylength+1):
  82         for i in range(workers):
  83             key = cat(random.choice(string.ascii_lowercase) for _ in range(keylength))
  84             worker_args.append((ciphertext, key,
  85                             initial_temperature, max_iterations, fitness))
  86
  87     with multiprocessing.Pool() as pool:
  88         breaks = pool.starmap(autokey_sa_break_worker,
  89                               worker_args, chunksize)
  90     if result_count &lt;= 1:
  91         return max(breaks, key=lambda k: k[1])
  92     else:
  93         return sorted(set(breaks), key=lambda k: k[1], reverse=True)[:result_count]
  94
  95
  96 def autokey_sa_break_worker(message, key,
  97                                      t0, max_iterations, fitness):
  98     temperature = t0
  99     dt = t0 / (0.9 * max_iterations)
 100
 101     plaintext = autokey_decipher(message, key)
 102     current_fitness = fitness(plaintext)
 103     current_key = key
 104
 105     best_key = current_key
 106     best_fitness = current_fitness
 107     best_plaintext = plaintext
 108
 109     # print(&#39;starting for&#39;, max_iterations)
 110     for i in range(max_iterations):
 111         swap_pos = random.randrange(len(current_key))
 112         swap_char = random.choice(string.ascii_lowercase)
 113
 114         new_key = current_key[:swap_pos] + swap_char + current_key[swap_pos+1:]
 115
 116         plaintext = autokey_decipher(message, new_key)
 117         new_fitness = fitness(plaintext)
 118         try:
 119             sa_chance = math.exp((new_fitness - current_fitness) / temperature)
 120         except (OverflowError, ZeroDivisionError):
 121             # print(&#39;exception triggered: new_fit {}, current_fit {}, temp {}&#39;.format(new_fitness, current_fitness, temperature))
 122             sa_chance = 0
 123         if (new_fitness &gt; current_fitness or random.random() &lt; sa_chance):
 124             current_fitness = new_fitness
 125             current_key = new_key
 126
 127         if current_fitness &gt; best_fitness:
 128             best_key = current_key
 129             best_fitness = current_fitness
 130             best_plaintext = plaintext
 131
 132         temperature = max(temperature - dt, 0.001)
 133
 134 #     print(best_key, best_fitness, best_plaintext[:70])
 135     return best_key, best_fitness # current_alphabet, current_fitness
 136
 137 if __name__ == &#34;__main__&#34;:
 138     import doctest</code></pre>
 139 </details>
 140 </section>
 141 <section>
 142 </section>
 143 <section>
 144 </section>
 145 <section>
 146 <h2 class="section-title" id="header-functions">Functions</h2>
 147 <dl>
 148 <dt id="szyfrow.autokey.autokey_decipher"><code class="name flex">
 149 <span>def <span class="ident">autokey_decipher</span></span>(<span>ciphertext, keyword)</span>
 150 </code></dt>
 151 <dd>
 152 <div class="desc"><p>Decipher with the autokey cipher</p>
 153 <pre><code class="language-python-repl">&gt;&gt;&gt; autokey_decipher('wmpmmxxaeyhbryoca', 'kilt')
 154 'meetatthefountain'
 155 </code></pre></div>
 156 <details class="source">
 157 <summary>
 158 <span>Expand source code</span>
 159 </summary>
 160 <pre><code class="python">def autokey_decipher(ciphertext, keyword):
 161     &#34;&#34;&#34;Decipher with the autokey cipher
 162
 163     &gt;&gt;&gt; autokey_decipher(&#39;wmpmmxxaeyhbryoca&#39;, &#39;kilt&#39;)
 164     &#39;meetatthefountain&#39;
 165     &#34;&#34;&#34;
 166     plaintext = []
 167     keys = list(keyword)
 168     for c in ciphertext:
 169         plaintext_letter = caesar_decipher_letter(c, pos(keys[0]))
 170         plaintext += [plaintext_letter]
 171         keys = keys[1:] + [plaintext_letter]
 172     return cat(plaintext)</code></pre>
 173 </details>
 174 </dd>
 175 <dt id="szyfrow.autokey.autokey_encipher"><code class="name flex">
 176 <span>def <span class="ident">autokey_encipher</span></span>(<span>message, keyword)</span>
 177 </code></dt>
 178 <dd>
 179 <div class="desc"><p>Encipher with the autokey cipher</p>
 180 <pre><code class="language-python-repl">&gt;&gt;&gt; autokey_encipher('meetatthefountain', 'kilt')
 181 'wmpmmxxaeyhbryoca'
 182 </code></pre></div>
 183 <details class="source">
 184 <summary>
 185 <span>Expand source code</span>
 186 </summary>
 187 <pre><code class="python">def autokey_encipher(message, keyword):
 188     &#34;&#34;&#34;Encipher with the autokey cipher
 189
 190     &gt;&gt;&gt; autokey_encipher(&#39;meetatthefountain&#39;, &#39;kilt&#39;)
 191     &#39;wmpmmxxaeyhbryoca&#39;
 192     &#34;&#34;&#34;
 193     shifts = [pos(l) for l in keyword + message]
 194     pairs = zip(message, shifts)
 195     return cat([caesar_encipher_letter(l, k) for l, k in pairs])</code></pre>
 196 </details>
 197 </dd>
 198 <dt id="szyfrow.autokey.autokey_sa_break"><code class="name flex">
 199 <span>def <span class="ident">autokey_sa_break</span></span>(<span>message, min_keylength=2, max_keylength=20, workers=10, initial_temperature=200, max_iterations=20000, fitness=&lt;function Pletters&gt;, chunksize=1, result_count=1)</span>
 200 </code></dt>
 201 <dd>
 202 <div class="desc"><p>Break an autokey cipher by simulated annealing</p></div>
 203 <details class="source">
 204 <summary>
 205 <span>Expand source code</span>
 206 </summary>
 207 <pre><code class="python">def autokey_sa_break( message
 208                     , min_keylength=2
 209                     , max_keylength=20
 210                     , workers=10
 211                     , initial_temperature=200
 212                     , max_iterations=20000
 213                     , fitness=Pletters
 214                     , chunksize=1
 215                     , result_count=1
 216                     ):
 217     &#34;&#34;&#34;Break an autokey cipher by simulated annealing
 218     &#34;&#34;&#34;
 219     worker_args = []
 220     ciphertext = sanitise(message)
 221     for keylength in range(min_keylength, max_keylength+1):
 222         for i in range(workers):
 223             key = cat(random.choice(string.ascii_lowercase) for _ in range(keylength))
 224             worker_args.append((ciphertext, key,
 225                             initial_temperature, max_iterations, fitness))
 226
 227     with multiprocessing.Pool() as pool:
 228         breaks = pool.starmap(autokey_sa_break_worker,
 229                               worker_args, chunksize)
 230     if result_count &lt;= 1:
 231         return max(breaks, key=lambda k: k[1])
 232     else:
 233         return sorted(set(breaks), key=lambda k: k[1], reverse=True)[:result_count]</code></pre>
 234 </details>
 235 </dd>
 236 <dt id="szyfrow.autokey.autokey_sa_break_worker"><code class="name flex">
 237 <span>def <span class="ident">autokey_sa_break_worker</span></span>(<span>message, key, t0, max_iterations, fitness)</span>
 238 </code></dt>
 239 <dd>
 240 <div class="desc"></div>
 241 <details class="source">
 242 <summary>
 243 <span>Expand source code</span>
 244 </summary>
 245 <pre><code class="python">def autokey_sa_break_worker(message, key,
 246                                      t0, max_iterations, fitness):
 247     temperature = t0
 248     dt = t0 / (0.9 * max_iterations)
 249
 250     plaintext = autokey_decipher(message, key)
 251     current_fitness = fitness(plaintext)
 252     current_key = key
 253
 254     best_key = current_key
 255     best_fitness = current_fitness
 256     best_plaintext = plaintext
 257
 258     # print(&#39;starting for&#39;, max_iterations)
 259     for i in range(max_iterations):
 260         swap_pos = random.randrange(len(current_key))
 261         swap_char = random.choice(string.ascii_lowercase)
 262
 263         new_key = current_key[:swap_pos] + swap_char + current_key[swap_pos+1:]
 264
 265         plaintext = autokey_decipher(message, new_key)
 266         new_fitness = fitness(plaintext)
 267         try:
 268             sa_chance = math.exp((new_fitness - current_fitness) / temperature)
 269         except (OverflowError, ZeroDivisionError):
 270             # print(&#39;exception triggered: new_fit {}, current_fit {}, temp {}&#39;.format(new_fitness, current_fitness, temperature))
 271             sa_chance = 0
 272         if (new_fitness &gt; current_fitness or random.random() &lt; sa_chance):
 273             current_fitness = new_fitness
 274             current_key = new_key
 275
 276         if current_fitness &gt; best_fitness:
 277             best_key = current_key
 278             best_fitness = current_fitness
 279             best_plaintext = plaintext
 280
 281         temperature = max(temperature - dt, 0.001)
 282
 283 #     print(best_key, best_fitness, best_plaintext[:70])
 284     return best_key, best_fitness # current_alphabet, current_fitness</code></pre>
 285 </details>
 286 </dd>
 287 <dt id="szyfrow.autokey.cat"><code class="name flex">
 288 <span>def <span class="ident">cat</span></span>(<span>iterable, /)</span>
 289 </code></dt>
 290 <dd>
 291 <div class="desc"><p>Concatenate any number of strings.</p>
 292 <p>The string whose method is called is inserted in between each given string.
 293 The result is returned as a new string.</p>
 294 <p>Example: '.'.join(['ab', 'pq', 'rs']) -&gt; 'ab.pq.rs'</p></div>
 295 </dd>
 296 <dt id="szyfrow.autokey.lcat"><code class="name flex">
 297 <span>def <span class="ident">lcat</span></span>(<span>iterable, /)</span>
 298 </code></dt>
 299 <dd>
 300 <div class="desc"><p>Concatenate any number of strings.</p>
 301 <p>The string whose method is called is inserted in between each given string.
 302 The result is returned as a new string.</p>
 303 <p>Example: '.'.join(['ab', 'pq', 'rs']) -&gt; 'ab.pq.rs'</p></div>
 304 </dd>
 305 <dt id="szyfrow.autokey.wcat"><code class="name flex">
 306 <span>def <span class="ident">wcat</span></span>(<span>iterable, /)</span>
 307 </code></dt>
 308 <dd>
 309 <div class="desc"><p>Concatenate any number of strings.</p>
 310 <p>The string whose method is called is inserted in between each given string.
 311 The result is returned as a new string.</p>
 312 <p>Example: '.'.join(['ab', 'pq', 'rs']) -&gt; 'ab.pq.rs'</p></div>
 313 </dd>
 314 </dl>
 315 </section>
 316 <section>
 317 </section>
 318 </article>
 319 <nav id="sidebar">
 320 <h1>Index</h1>
 321 <div class="toc">
 322 <ul></ul>
 323 </div>
 324 <ul id="index">
 325 <li><h3>Super-module</h3>
 326 <ul>
 327 <li><code><a title="szyfrow" href="index.html">szyfrow</a></code></li>
 328 </ul>
 329 </li>
 330 <li><h3><a href="#header-functions">Functions</a></h3>
 331 <ul class="">
 332 <li><code><a title="szyfrow.autokey.autokey_decipher" href="#szyfrow.autokey.autokey_decipher">autokey_decipher</a></code></li>
 333 <li><code><a title="szyfrow.autokey.autokey_encipher" href="#szyfrow.autokey.autokey_encipher">autokey_encipher</a></code></li>
 334 <li><code><a title="szyfrow.autokey.autokey_sa_break" href="#szyfrow.autokey.autokey_sa_break">autokey_sa_break</a></code></li>
 335 <li><code><a title="szyfrow.autokey.autokey_sa_break_worker" href="#szyfrow.autokey.autokey_sa_break_worker">autokey_sa_break_worker</a></code></li>
 336 <li><code><a title="szyfrow.autokey.cat" href="#szyfrow.autokey.cat">cat</a></code></li>
 337 <li><code><a title="szyfrow.autokey.lcat" href="#szyfrow.autokey.lcat">lcat</a></code></li>
 338 <li><code><a title="szyfrow.autokey.wcat" href="#szyfrow.autokey.wcat">wcat</a></code></li>
 339 </ul>
 340 </li>
 341 </ul>
 342 </nav>
 343 </main>
 344 <footer id="footer">
 345 <p>Generated by <a href="https://pdoc3.github.io/pdoc"><cite>pdoc</cite> 0.9.2</a>.</p>
 346 </footer>
 347 </body>
 348 </html>