HTW Berlin Fachbereich 4 Internationaler Studiengang Internationale Medieninformatik (Bachelor) Aktuelles - Medien: Kryptographie Winter Term 2010/11

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 FTLNBE AUAUM XQEEF QRKAF YMZAD IPWJQ TLVAY QNXRV IQXBK
   
   
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 Wednesday. 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.