HTW Berlin Fachbereich 4 Internationaler Studiengang Internationale Medieninformatik (Bachelor) Aktuelle Themen: Cryptography Winter Term 2016/17

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 ciphertexts that were produced using Caesar Codes?
   
   vtxltk ibvdxw oxkr lbfiex xgvkrimbhg fxmahw
   
   vgvfv zcbeg naggb xabjn fzhpu nobhg pelcg btenc ulnfc bffvoy rbfih
   
   
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. What is the plaintext for the following ciphertext that was produced using a monoalphabetic cipher?
   
   EXUKM HKNKY YLHYZ HTOXU SAOKE APIXQ UQSET ZOSEA OHKEH EPHQN ZGHOS HQAKO LSKWK NPRIJ
   
   
5. Using a Vigenère code and the keyword enigma, determine the plaintext for this ciphertext:
   
   KEMGF JSOGU GWIEM KMSMY GGNLI GWJQC SQMZT IWFPU DTQRA YMGIK
   
   
   

6. For (bored) experts: we encoded this using Vigenère code and lost the key. What might it be?
          
        EPUUT XZWAX KYCRM WTYMY CPGWZ OJWQI UHTZD QMVNK NVBWB 
        REYVW XMBUM VQQRD IBQLL MRLTG VVWOU DOKIB QLLMN EBAIE 
        IKCUM BVRNR GBKSU WRLLL MGDNK OGMRH CNWPW FVHWT ETBWB 
        RKYJA KLZLO QIYSP PWPLL MYHBK VUIVC OPEGD HVVOG SAQGI 
        MVCQN HNSKG HFNEG KSGLU IWGAE VNXHP GRAMW FHRCP GTVRY 
        IDPGS HBVRV VNQDX BSEQL HGWAM HUIUB GILEC EOLHI OKXZN 
        CLHIT HPWZW HFHHX IZJEB MCPIM OEWWI DEWWW AKEIV HEXXN 
        GNMOM
   

Your report is due in the Moodle Room by 22.00 before the next session. 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.