HTW Berlin Medieninformatik

HTW Berlin
Fachbereich 4
Internationaler Studiengang
Internationale Medieninformatik (Bachelor)
Aktuelle Themen: Cryptography
Winter Term 2013/14

Lab 0: Simple Ciphers


Try your hand on the following ciphertexts! Can you discover the plaintext? Don't use any of the online tools available. You need to describe the process by which you solved the ciphers, not just give a solution, for full points.

  1. What is the plaintext for the following ciphertext that was produced using a Caesar Code?

    vtxltk ibvdxw oxkr lbfiex xgvkrimbhg fxmahw

  2. What is the plaintext for the following ciphertext that was produced using a Scytale?

    IBSTSYLHRDENTTVTHASEOEIXTHIIHIVIMDNNTYISOASEMEFCGDONOUTIRPTOOTOUK

    Describe in your report how you cracked this cipher!

  3. What is the plaintext for the following ciphertext that was produced using a monoalphabetic cipher?

    XDLLADIXPPFKQEBYFPELMPELPQBIFKQEBABSFIPPBXQCLOQVLKBABDO
    BBPXKAQEFOQBBKJFKRQBPKLOQEBXPQXKAYVKLOQEJXFKYOXKZEPBS
    BKQEIFJYBXPQPFABPELLQCOLJQEBIBCQBVBLCQEBABXQEPEBXAXYBBI
    FKBCOLJQEBQOBBQEOLRDEQEBPELQCFCQVCBBQLRQ

  4. Using a Vigenère code and the keyword enigma, determine the plaintext for this ciphertext:

    XUQYU SKEMG FTLNB EAUAU MXQEE FQRKA FYMZA DIPWJ QTLVA YQNXR VIQXB KLDNF

  5. For (bored) experts: we encoded this using Vigenère code and lost the key. What might it be?

    XTLTE CPHXI UKNQW TPGQW UPLQM OPHGR LYUOO CLLQR WTAQR FCYHI SDWTP VPMEI
    MEYZX FINMP TFYNY ORMMY GRUNI HPMFI MWNPM FDNGH FYNQR TTHPF FTGPI LZXUI SPHHI
    SKQQM GPFFH BOYDX FINLY LFLLA BCXMA JCXQR TNBXY FDMQP XTLWP JNBHI SWIDI OSUFX
    FYEAR OEYZA JCUGG IVYUR FWIQW VYABV BPMQR UTYDI OHCDL BMYZE OOLQZ FCMBV PNBQR
    EPMII HPHQM OPHQY FLORK BMYLY TEYXP FYRJB

Your report is due in the Moodle Room by 23.00 next Sunday. You need to describe what method you used to crack the code. If you were unable to crack it, please record what you did to attempt to solve the code. You may work in groups of two, but each of you must hand in their own copy of the report.


Copyright 2013 Dr. Hermann Thiel & Prof. Dr. Debora Weber-Wulff – CC-BY-NC-SA

This material is jointly prepared by Dr. Hermann Thiel and Prof. Dr. Debora Weber-Wulff. Some of the material may come from other sources and is denoted by the copyright notices on the individual pages.