railfence-experiment-1.ipynb

   1 {
   2  "metadata": {
   3   "name": "",
   4   "signature": "sha256:c4879f550d49d776eff31ee9f3296756aab1dcd81e1e5aad61ade46d9b29600d"
   5  },
   6  "nbformat": 3,
   7  "nbformat_minor": 0,
   8  "worksheets": [
   9   {
  10    "cells": [
  11     {
  12      "cell_type": "code",
  13      "collapsed": false,
  14      "input": [
  15       "from cipher import *"
  16      ],
  17      "language": "python",
  18      "metadata": {},
  19      "outputs": [],
  20      "prompt_number": 1
  21     },
  22     {
  23      "cell_type": "code",
  24      "collapsed": false,
  25      "input": [
  26       "railfence_encipherl('hellothere', 3)"
  27      ],
  28      "language": "python",
  29      "metadata": {},
  30      "outputs": [
  31       {
  32        "metadata": {},
  33        "output_type": "pyout",
  34        "prompt_number": 25,
  35        "text": [
  36         "'horeltee lh '"
  37        ]
  38       }
  39      ],
  40      "prompt_number": 25
  41     },
  42     {
  43      "cell_type": "code",
  44      "collapsed": false,
  45      "input": [
  46       "message = 'hellothere'\n",
  47       "height = 2"
  48      ],
  49      "language": "python",
  50      "metadata": {},
  51      "outputs": [],
  52      "prompt_number": 169
  53     },
  54     {
  55      "cell_type": "code",
  56      "collapsed": false,
  57      "input": [
  58       "sections = chunks(message, (height - 1) * 2, fillvalue='!')\n",
  59       "sections"
  60      ],
  61      "language": "python",
  62      "metadata": {},
  63      "outputs": [
  64       {
  65        "metadata": {},
  66        "output_type": "pyout",
  67        "prompt_number": 170,
  68        "text": [
  69         "['he', 'll', 'ot', 'he', 're']"
  70        ]
  71       }
  72      ],
  73      "prompt_number": 170
  74     },
  75     {
  76      "cell_type": "code",
  77      "collapsed": false,
  78      "input": [
  79       "rows = [s[0] for s in sections]\n",
  80       "rows"
  81      ],
  82      "language": "python",
  83      "metadata": {},
  84      "outputs": [
  85       {
  86        "metadata": {},
  87        "output_type": "pyout",
  88        "prompt_number": 171,
  89        "text": [
  90         "['h', 'l', 'o', 'h', 'r']"
  91        ]
  92       }
  93      ],
  94      "prompt_number": 171
  95     },
  96     {
  97      "cell_type": "code",
  98      "collapsed": false,
  99      "input": [
 100       "for r in range(1, height - 1):\n",
 101       "        rows += [s[r] + s[-r] for s in sections]\n",
 102       "rows"
 103      ],
 104      "language": "python",
 105      "metadata": {},
 106      "outputs": [
 107       {
 108        "metadata": {},
 109        "output_type": "pyout",
 110        "prompt_number": 172,
 111        "text": [
 112         "['h', 'l', 'o', 'h', 'r']"
 113        ]
 114       }
 115      ],
 116      "prompt_number": 172
 117     },
 118     {
 119      "cell_type": "code",
 120      "collapsed": false,
 121      "input": [
 122       "rows += [s[height - 1] for s in sections]\n",
 123       "rows"
 124      ],
 125      "language": "python",
 126      "metadata": {},
 127      "outputs": [
 128       {
 129        "metadata": {},
 130        "output_type": "pyout",
 131        "prompt_number": 173,
 132        "text": [
 133         "['h', 'l', 'o', 'h', 'r', 'e', 'l', 't', 'e', 'e']"
 134        ]
 135       }
 136      ],
 137      "prompt_number": 173
 138     },
 139     {
 140      "cell_type": "code",
 141      "collapsed": false,
 142      "input": [
 143       "ciphertext = ''.join(rows)\n",
 144       "ciphertext"
 145      ],
 146      "language": "python",
 147      "metadata": {},
 148      "outputs": [
 149       {
 150        "metadata": {},
 151        "output_type": "pyout",
 152        "prompt_number": 174,
 153        "text": [
 154         "'hlohreltee'"
 155        ]
 156       }
 157      ],
 158      "prompt_number": 174
 159     },
 160     {
 161      "cell_type": "code",
 162      "collapsed": false,
 163      "input": [
 164       "def railfence_encipherl(message, height, fillvalue=' '):\n",
 165       "    \"\"\"Railfence cipher\n",
 166       "    \"\"\"\n",
 167       "    sections = chunks(message, (height - 1) * 2, fillvalue=fillvalue)\n",
 168       "    # Add the top row\n",
 169       "    rows = [s[0] for s in sections]\n",
 170       "    # process the middle rows of the grid\n",
 171       "    for r in range(1, height - 1):\n",
 172       "        rows += [s[r] + s[-r] for s in sections]\n",
 173       "    # process the bottom row\n",
 174       "    rows += [s[height - 1] for s in sections]\n",
 175       "    return ''.join(rows)"
 176      ],
 177      "language": "python",
 178      "metadata": {},
 179      "outputs": [],
 180      "prompt_number": 24
 181     },
 182     {
 183      "cell_type": "code",
 184      "collapsed": false,
 185      "input": [
 186       "ciphertext = railfence_encipherl(message, height, fillvalue='!')\n",
 187       "ciphertext"
 188      ],
 189      "language": "python",
 190      "metadata": {},
 191      "outputs": [
 192       {
 193        "metadata": {},
 194        "output_type": "pyout",
 195        "prompt_number": 175,
 196        "text": [
 197         "'hlohreltee'"
 198        ]
 199       }
 200      ],
 201      "prompt_number": 175
 202     },
 203     {
 204      "cell_type": "code",
 205      "collapsed": false,
 206      "input": [
 207       "len(ciphertext)"
 208      ],
 209      "language": "python",
 210      "metadata": {},
 211      "outputs": [
 212       {
 213        "metadata": {},
 214        "output_type": "pyout",
 215        "prompt_number": 176,
 216        "text": [
 217         "10"
 218        ]
 219       }
 220      ],
 221      "prompt_number": 176
 222     },
 223     {
 224      "cell_type": "code",
 225      "collapsed": false,
 226      "input": [
 227       "n_secs = len(ciphertext) // ((height - 1) * 2)\n",
 228       "n_secs"
 229      ],
 230      "language": "python",
 231      "metadata": {},
 232      "outputs": [
 233       {
 234        "metadata": {},
 235        "output_type": "pyout",
 236        "prompt_number": 177,
 237        "text": [
 238         "5"
 239        ]
 240       }
 241      ],
 242      "prompt_number": 177
 243     },
 244     {
 245      "cell_type": "code",
 246      "collapsed": false,
 247      "input": [
 248       "ciphertext[:5]"
 249      ],
 250      "language": "python",
 251      "metadata": {},
 252      "outputs": [
 253       {
 254        "metadata": {},
 255        "output_type": "pyout",
 256        "prompt_number": 109,
 257        "text": [
 258         "'hhaes'"
 259        ]
 260       }
 261      ],
 262      "prompt_number": 109
 263     },
 264     {
 265      "cell_type": "code",
 266      "collapsed": false,
 267      "input": [
 268       "ciphertext[5:15]"
 269      ],
 270      "language": "python",
 271      "metadata": {},
 272      "outputs": [
 273       {
 274        "metadata": {},
 275        "output_type": "pyout",
 276        "prompt_number": 110,
 277        "text": [
 278         "'etevshae!!'"
 279        ]
 280       }
 281      ],
 282      "prompt_number": 110
 283     },
 284     {
 285      "cell_type": "code",
 286      "collapsed": false,
 287      "input": [
 288       "ciphertext[15:25]"
 289      ],
 290      "language": "python",
 291      "metadata": {},
 292      "outputs": [
 293       {
 294        "metadata": {},
 295        "output_type": "pyout",
 296        "prompt_number": 111,
 297        "text": [
 298         "'lorateri!!'"
 299        ]
 300       }
 301      ],
 302      "prompt_number": 111
 303     },
 304     {
 305      "cell_type": "code",
 306      "collapsed": false,
 307      "input": [
 308       "ciphertext[25:]"
 309      ],
 310      "language": "python",
 311      "metadata": {},
 312      "outputs": [
 313       {
 314        "metadata": {},
 315        "output_type": "pyout",
 316        "prompt_number": 112,
 317        "text": [
 318         "'lemt!'"
 319        ]
 320       }
 321      ],
 322      "prompt_number": 112
 323     },
 324     {
 325      "cell_type": "code",
 326      "collapsed": false,
 327      "input": [
 328       "downrows = [ciphertext[:n_secs]]\n",
 329       "uprows = []\n",
 330       "downrows, uprows"
 331      ],
 332      "language": "python",
 333      "metadata": {},
 334      "outputs": [
 335       {
 336        "metadata": {},
 337        "output_type": "pyout",
 338        "prompt_number": 180,
 339        "text": [
 340         "(['hlohr'], [])"
 341        ]
 342       }
 343      ],
 344      "prompt_number": 180
 345     },
 346     {
 347      "cell_type": "code",
 348      "collapsed": false,
 349      "input": [
 350       "for r in range(1, height, 2):\n",
 351       "    midrow = ciphertext[r * n_secs:(r+2)*n_secs]\n",
 352       "    downrows += [''.join([midrow[i] for i in range(0, len(midrow), 2)])]\n",
 353       "    uprows = [''.join([midrow[i] for i in range(1, len(midrow), 2)])] + uprows\n",
 354       "downrows, uprows"
 355      ],
 356      "language": "python",
 357      "metadata": {},
 358      "outputs": [
 359       {
 360        "metadata": {},
 361        "output_type": "pyout",
 362        "prompt_number": 179,
 363        "text": [
 364         "(['hlohr', 'ete'], ['le'])"
 365        ]
 366       }
 367      ],
 368      "prompt_number": 179
 369     },
 370     {
 371      "cell_type": "code",
 372      "collapsed": false,
 373      "input": [
 374       "downrows += [ciphertext[-n_secs:]]\n",
 375       "downrows, uprows"
 376      ],
 377      "language": "python",
 378      "metadata": {},
 379      "outputs": [
 380       {
 381        "metadata": {},
 382        "output_type": "pyout",
 383        "prompt_number": 181,
 384        "text": [
 385         "(['hlohr', 'eltee'], [])"
 386        ]
 387       }
 388      ],
 389      "prompt_number": 181
 390     },
 391     {
 392      "cell_type": "code",
 393      "collapsed": false,
 394      "input": [
 395       "rows = downrows + uprows\n",
 396       "rows"
 397      ],
 398      "language": "python",
 399      "metadata": {},
 400      "outputs": [
 401       {
 402        "metadata": {},
 403        "output_type": "pyout",
 404        "prompt_number": 182,
 405        "text": [
 406         "['hlohr', 'eltee']"
 407        ]
 408       }
 409      ],
 410      "prompt_number": 182
 411     },
 412     {
 413      "cell_type": "code",
 414      "collapsed": false,
 415      "input": [
 416       "midrow = rows[1]\n",
 417       "midrow"
 418      ],
 419      "language": "python",
 420      "metadata": {},
 421      "outputs": [
 422       {
 423        "metadata": {},
 424        "output_type": "pyout",
 425        "prompt_number": 64,
 426        "text": [
 427         "'elteevsmhate!!'"
 428        ]
 429       }
 430      ],
 431      "prompt_number": 64
 432     },
 433     {
 434      "cell_type": "code",
 435      "collapsed": false,
 436      "input": [
 437       "mid_down = ''.join([midrow[i] for i in range(0, len(midrow), 2)])\n",
 438       "mid_down"
 439      ],
 440      "language": "python",
 441      "metadata": {},
 442      "outputs": [
 443       {
 444        "metadata": {},
 445        "output_type": "pyout",
 446        "prompt_number": 65,
 447        "text": [
 448         "'etesht!'"
 449        ]
 450       }
 451      ],
 452      "prompt_number": 65
 453     },
 454     {
 455      "cell_type": "code",
 456      "collapsed": false,
 457      "input": [
 458       "mid_up = ''.join([midrow[i] for i in range(1, len(midrow), 2)])\n",
 459       "mid_up"
 460      ],
 461      "language": "python",
 462      "metadata": {},
 463      "outputs": [
 464       {
 465        "metadata": {},
 466        "output_type": "pyout",
 467        "prompt_number": 66,
 468        "text": [
 469         "'levmae!'"
 470        ]
 471       }
 472      ],
 473      "prompt_number": 66
 474     },
 475     {
 476      "cell_type": "code",
 477      "collapsed": false,
 478      "input": [
 479       "rows = downrows + uprows\n",
 480       "rows"
 481      ],
 482      "language": "python",
 483      "metadata": {},
 484      "outputs": [
 485       {
 486        "metadata": {},
 487        "output_type": "pyout",
 488        "prompt_number": 139,
 489        "text": [
 490         "['hhaesspfoilcs',\n",
 491         " 'eesataitrnfi!',\n",
 492         " 'lrtrhleetgep!',\n",
 493         " 'lemtiocxernh!',\n",
 494         " 'oaeisnetsace!',\n",
 495         " 'tvheigoftier!']"
 496        ]
 497       }
 498      ],
 499      "prompt_number": 139
 500     },
 501     {
 502      "cell_type": "code",
 503      "collapsed": false,
 504      "input": [
 505       "''.join(letter for section in zip(*rows) for letter in section)"
 506      ],
 507      "language": "python",
 508      "metadata": {},
 509      "outputs": [
 510       {
 511        "metadata": {},
 512        "output_type": "pyout",
 513        "prompt_number": 183,
 514        "text": [
 515         "'hellothere'"
 516        ]
 517       }
 518      ],
 519      "prompt_number": 183
 520     },
 521     {
 522      "cell_type": "code",
 523      "collapsed": false,
 524      "input": [
 525       "def railfence_decipherl(message, height):\n",
 526       "    n_secs = len(message) // ((height - 1) * 2)\n",
 527       "    downrows = [message[:n_secs]]\n",
 528       "    uprows = []\n",
 529       "    for r in range(height-2):\n",
 530       "        midrow = ciphertext[(2 * r + 1) * n_secs:(2 * r + 1) * n_secs + n_secs * 2]\n",
 531       "        downrows += [''.join([midrow[i] for i in range(0, len(midrow), 2)])]\n",
 532       "        uprows = [''.join([midrow[i] for i in range(1, len(midrow), 2)])] + uprows\n",
 533       "    downrows += [message[-n_secs:]]\n",
 534       "    rows = downrows + uprows\n",
 535       "    return ''.join(letter for section in zip(*rows) for letter in section)"
 536      ],
 537      "language": "python",
 538      "metadata": {},
 539      "outputs": [],
 540      "prompt_number": 249
 541     },
 542     {
 543      "cell_type": "code",
 544      "collapsed": false,
 545      "input": [
 546       "ciphertext"
 547      ],
 548      "language": "python",
 549      "metadata": {},
 550      "outputs": [
 551       {
 552        "metadata": {},
 553        "output_type": "pyout",
 554        "prompt_number": 154,
 555        "text": [
 556         "'hhaesetevshae!!lorateri!!lemt!'"
 557        ]
 558       }
 559      ],
 560      "prompt_number": 154
 561     },
 562     {
 563      "cell_type": "code",
 564      "collapsed": false,
 565      "input": [
 566       "railfence_decipherl(ciphertext, 4)"
 567      ],
 568      "language": "python",
 569      "metadata": {},
 570      "outputs": [
 571       {
 572        "metadata": {},
 573        "output_type": "pyout",
 574        "prompt_number": 155,
 575        "text": [
 576         "''"
 577        ]
 578       }
 579      ],
 580      "prompt_number": 155
 581     },
 582     {
 583      "cell_type": "code",
 584      "collapsed": false,
 585      "input": [
 586       "plaintext = sanitise('hello there avast me hearties this is a long piece of text for testing railfence ciphers')\n",
 587       "plaintext"
 588      ],
 589      "language": "python",
 590      "metadata": {},
 591      "outputs": [
 592       {
 593        "metadata": {},
 594        "output_type": "pyout",
 595        "prompt_number": 250,
 596        "text": [
 597         "'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'"
 598        ]
 599       }
 600      ],
 601      "prompt_number": 250
 602     },
 603     {
 604      "cell_type": "code",
 605      "collapsed": false,
 606      "input": [
 607       "ciphertext = railfence_encipherl(plaintext, height, fillvalue='!')\n",
 608       "ciphertext"
 609      ],
 610      "language": "python",
 611      "metadata": {},
 612      "outputs": [
 613       {
 614        "metadata": {},
 615        "output_type": "pyout",
 616        "prompt_number": 163,
 617        "text": [
 618         "'hhaesspfoilcsetevshaetiagiotfrtnifeir!!loraterihslneeettsgaecpe!!lemtiocxernh!'"
 619        ]
 620       }
 621      ],
 622      "prompt_number": 163
 623     },
 624     {
 625      "cell_type": "code",
 626      "collapsed": false,
 627      "input": [
 628       "railfence_decipherl(ciphertext, height)"
 629      ],
 630      "language": "python",
 631      "metadata": {},
 632      "outputs": [
 633       {
 634        "metadata": {},
 635        "output_type": "pyout",
 636        "prompt_number": 164,
 637        "text": [
 638         "'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers!!!!!'"
 639        ]
 640       }
 641      ],
 642      "prompt_number": 164
 643     },
 644     {
 645      "cell_type": "code",
 646      "collapsed": false,
 647      "input": [
 648       "railfence_encipherl('hellothere', 2)"
 649      ],
 650      "language": "python",
 651      "metadata": {},
 652      "outputs": [
 653       {
 654        "metadata": {},
 655        "output_type": "pyout",
 656        "prompt_number": 186,
 657        "text": [
 658         "'hlohreltee'"
 659        ]
 660       }
 661      ],
 662      "prompt_number": 186
 663     },
 664     {
 665      "cell_type": "code",
 666      "collapsed": false,
 667      "input": [
 668       "railfence_decipherl('hlohreltee', 2)"
 669      ],
 670      "language": "python",
 671      "metadata": {},
 672      "outputs": [
 673       {
 674        "metadata": {},
 675        "output_type": "pyout",
 676        "prompt_number": 187,
 677        "text": [
 678         "'hellothere'"
 679        ]
 680       }
 681      ],
 682      "prompt_number": 187
 683     },
 684     {
 685      "cell_type": "code",
 686      "collapsed": false,
 687      "input": [
 688       "[i for i in range(1, 2, 2)]"
 689      ],
 690      "language": "python",
 691      "metadata": {},
 692      "outputs": [
 693       {
 694        "metadata": {},
 695        "output_type": "pyout",
 696        "prompt_number": 184,
 697        "text": [
 698         "[1]"
 699        ]
 700       }
 701      ],
 702      "prompt_number": 184
 703     },
 704     {
 705      "cell_type": "code",
 706      "collapsed": false,
 707      "input": [
 708       "railfence_encipherl('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 10, fillvalue='!')"
 709      ],
 710      "language": "python",
 711      "metadata": {},
 712      "outputs": [
 713       {
 714        "metadata": {},
 715        "output_type": "pyout",
 716        "prompt_number": 265,
 717        "text": [
 718         "'hepisehagitnr!!lernesge!!lmtocerh!!otiletap!!tseaorii!!hassfolc!!evtitffe!!rahsetec!!eixn!'"
 719        ]
 720       }
 721      ],
 722      "prompt_number": 265
 723     },
 724     {
 725      "cell_type": "code",
 726      "collapsed": false,
 727      "input": [
 728       "railfence_decipherl('horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihr!!lhateihsnefttiaece!', 3)"
 729      ],
 730      "language": "python",
 731      "metadata": {},
 732      "outputs": [
 733       {
 734        "metadata": {},
 735        "output_type": "pyout",
 736        "prompt_number": 191,
 737        "text": [
 738         "'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers!!!'"
 739        ]
 740       }
 741      ],
 742      "prompt_number": 191
 743     },
 744     {
 745      "cell_type": "code",
 746      "collapsed": false,
 747      "input": [
 748       "railfence_encipherl('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 4, fillvalue='!')"
 749      ],
 750      "language": "python",
 751      "metadata": {},
 752      "outputs": [
 753       {
 754        "metadata": {},
 755        "output_type": "pyout",
 756        "prompt_number": 240,
 757        "text": [
 758         "'hhaesspfoilcsetevshaetiagiotfrtnifeir!!loraterihslneeettsgaecpe!!lemtiocxernh!'"
 759        ]
 760       }
 761      ],
 762      "prompt_number": 240
 763     },
 764     {
 765      "cell_type": "code",
 766      "collapsed": false,
 767      "input": [
 768       "railfence_decipherl('hhaesspfoilcsetevshaetiagiotfrtnifeir!!loraterihslneeettsgaecpe!!lemtiocxernh!', 4)"
 769      ],
 770      "language": "python",
 771      "metadata": {},
 772      "outputs": [
 773       {
 774        "metadata": {},
 775        "output_type": "pyout",
 776        "prompt_number": 241,
 777        "text": [
 778         "'hmelfhhetettaaimaoecetcosfei!rsn!olrpntcvefrsxa!o!teilihirgaltintecixhehsst!in'"
 779        ]
 780       }
 781      ],
 782      "prompt_number": 241
 783     },
 784     {
 785      "cell_type": "code",
 786      "collapsed": false,
 787      "input": [
 788       "railfence_encipherl('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 5, fillvalue='!')"
 789      ],
 790      "language": "python",
 791      "metadata": {},
 792      "outputs": [
 793       {
 794        "metadata": {},
 795        "output_type": "pyout",
 796        "prompt_number": 238,
 797        "text": [
 798         "'hresleogcseeemhetaocofrnrner!!lhateihsnefttiaece!!ltvsatiigitxetifih!!oarspeslp!'"
 799        ]
 800       }
 801      ],
 802      "prompt_number": 238
 803     },
 804     {
 805      "cell_type": "code",
 806      "collapsed": false,
 807      "input": [
 808       "railfence_decipherl('hresleogcseeemhetaocofrnrner!!lhateihsnefttiaece!!ltvsatiigitxetifih!!oarspeslp!', 5)"
 809      ],
 810      "language": "python",
 811      "metadata": {},
 812      "outputs": [
 813       {
 814        "metadata": {},
 815        "output_type": "pyout",
 816        "prompt_number": 239,
 817        "text": [
 818         "'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers!!!!!!!'"
 819        ]
 820       }
 821      ],
 822      "prompt_number": 239
 823     },
 824     {
 825      "cell_type": "code",
 826      "collapsed": false,
 827      "input": [
 828       "len(railfence_encipherl('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 5, fillvalue='!'))"
 829      ],
 830      "language": "python",
 831      "metadata": {},
 832      "outputs": [
 833       {
 834        "metadata": {},
 835        "output_type": "pyout",
 836        "prompt_number": 199,
 837        "text": [
 838         "80"
 839        ]
 840       }
 841      ],
 842      "prompt_number": 199
 843     },
 844     {
 845      "cell_type": "code",
 846      "collapsed": false,
 847      "input": [
 848       "ciphertext = 'horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihr!!lhateihsnefttiaece!'\n",
 849       "height=3"
 850      ],
 851      "language": "python",
 852      "metadata": {},
 853      "outputs": [],
 854      "prompt_number": 226
 855     },
 856     {
 857      "cell_type": "code",
 858      "collapsed": false,
 859      "input": [
 860       "ciphertext = 'hhaesspfoilcsetevshaetiagiotfrtnifeir!!loraterihslneeettsgaecpe!!lemtiocxernh!'\n",
 861       "height=4"
 862      ],
 863      "language": "python",
 864      "metadata": {},
 865      "outputs": [],
 866      "prompt_number": 242
 867     },
 868     {
 869      "cell_type": "code",
 870      "collapsed": false,
 871      "input": [
 872       "ciphertext = 'hresleogcseeemhetaocofrnrner!!lhateihsnefttiaece!!ltvsatiigitxetifih!!oarspeslp!'\n",
 873       "height=5"
 874      ],
 875      "language": "python",
 876      "metadata": {},
 877      "outputs": [],
 878      "prompt_number": 226
 879     },
 880     {
 881      "cell_type": "code",
 882      "collapsed": false,
 883      "input": [
 884       "n_secs = len(ciphertext) // ((height - 1) * 2)\n",
 885       "n_secs"
 886      ],
 887      "language": "python",
 888      "metadata": {},
 889      "outputs": [
 890       {
 891        "metadata": {},
 892        "output_type": "pyout",
 893        "prompt_number": 243,
 894        "text": [
 895         "13"
 896        ]
 897       }
 898      ],
 899      "prompt_number": 243
 900     },
 901     {
 902      "cell_type": "code",
 903      "collapsed": false,
 904      "input": [
 905       "downrows = [ciphertext[:n_secs]]\n",
 906       "uprows = []\n",
 907       "downrows, uprows"
 908      ],
 909      "language": "python",
 910      "metadata": {},
 911      "outputs": [
 912       {
 913        "metadata": {},
 914        "output_type": "pyout",
 915        "prompt_number": 244,
 916        "text": [
 917         "(['hhaesspfoilcs'], [])"
 918        ]
 919       }
 920      ],
 921      "prompt_number": 244
 922     },
 923     {
 924      "cell_type": "code",
 925      "collapsed": false,
 926      "input": [
 927       "for r in range(height-2):\n",
 928       "    print('From', (2 * r + 1) * n_secs, 'to', (2 * r + 1) * n_secs + n_secs * 2)\n",
 929       "    midrow = ciphertext[(2 * r + 1) * n_secs:(2 * r + 1) * n_secs + n_secs * 2]\n",
 930       "    downrows += [''.join([midrow[i] for i in range(0, len(midrow), 2)])]\n",
 931       "    uprows = [''.join([midrow[i] for i in range(1, len(midrow), 2)])] + uprows\n",
 932       "downrows, uprows"
 933      ],
 934      "language": "python",
 935      "metadata": {},
 936      "outputs": [
 937       {
 938        "output_type": "stream",
 939        "stream": "stdout",
 940        "text": [
 941         "From 13 to 39\n",
 942         "From 39 to 65\n"
 943        ]
 944       },
 945       {
 946        "metadata": {},
 947        "output_type": "pyout",
 948        "prompt_number": 245,
 949        "text": [
 950         "(['hhaesspfoilcs', 'eesataitrnfi!', 'lrtrhleetgep!'],\n",
 951         " ['oaeisnetsace!', 'tvheigoftier!'])"
 952        ]
 953       }
 954      ],
 955      "prompt_number": 245
 956     },
 957     {
 958      "cell_type": "code",
 959      "collapsed": false,
 960      "input": [
 961       "downrows += [ciphertext[-n_secs:]]\n",
 962       "downrows, uprows"
 963      ],
 964      "language": "python",
 965      "metadata": {},
 966      "outputs": [
 967       {
 968        "metadata": {},
 969        "output_type": "pyout",
 970        "prompt_number": 246,
 971        "text": [
 972         "(['hhaesspfoilcs', 'eesataitrnfi!', 'lrtrhleetgep!', 'lemtiocxernh!'],\n",
 973         " ['oaeisnetsace!', 'tvheigoftier!'])"
 974        ]
 975       }
 976      ],
 977      "prompt_number": 246
 978     },
 979     {
 980      "cell_type": "code",
 981      "collapsed": false,
 982      "input": [
 983       "rows = downrows + uprows"
 984      ],
 985      "language": "python",
 986      "metadata": {},
 987      "outputs": [],
 988      "prompt_number": 247
 989     },
 990     {
 991      "cell_type": "code",
 992      "collapsed": false,
 993      "input": [
 994       "''.join(letter for section in zip(*rows) for letter in section)"
 995      ],
 996      "language": "python",
 997      "metadata": {},
 998      "outputs": [
 999       {
1000        "metadata": {},
1001        "output_type": "pyout",
1002        "prompt_number": 248,
1003        "text": [
1004         "'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers!!!!!'"
1005        ]
1006       }
1007      ],
1008      "prompt_number": 248
1009     },
1010     {
1011      "cell_type": "code",
1012      "collapsed": false,
1013      "input": [
1014       "[i for i in range(0)]"
1015      ],
1016      "language": "python",
1017      "metadata": {},
1018      "outputs": [
1019       {
1020        "metadata": {},
1021        "output_type": "pyout",
1022        "prompt_number": 236,
1023        "text": [
1024         "[]"
1025        ]
1026       }
1027      ],
1028      "prompt_number": 236
1029     },
1030     {
1031      "cell_type": "code",
1032      "collapsed": false,
1033      "input": [
1034       "height = 3\n",
1035       "ciphertext = railfence_encipherl(plaintext, height, fillvalue=' ')\n",
1036       "result = railfence_decipherl(ciphertext, height).strip()\n",
1037       "result == plaintext"
1038      ],
1039      "language": "python",
1040      "metadata": {},
1041      "outputs": [
1042       {
1043        "metadata": {},
1044        "output_type": "pyout",
1045        "prompt_number": 270,
1046        "text": [
1047         "True"
1048        ]
1049       }
1050      ],
1051      "prompt_number": 270
1052     },
1053     {
1054      "cell_type": "code",
1055      "collapsed": false,
1056      "input": [
1057       "ciphertext"
1058      ],
1059      "language": "python",
1060      "metadata": {},
1061      "outputs": [
1062       {
1063        "metadata": {},
1064        "output_type": "pyout",
1065        "prompt_number": 271,
1066        "text": [
1067         "'horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihr  lhateihsnefttiaece '"
1068        ]
1069       }
1070      ],
1071      "prompt_number": 271
1072     },
1073     {
1074      "cell_type": "code",
1075      "collapsed": false,
1076      "input": [],
1077      "language": "python",
1078      "metadata": {},
1079      "outputs": []
1080     }
1081    ],
1082    "metadata": {}
1083   }
1084  ]
1085 }