HTW Berlin Fachbereich 4 Internationaler Studiengang Internationale Medieninformatik (Bachelor) Aktuelle Themen: Cryptography Winter Term 2024/25

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? Don't use a program, do this by hand and show your work.
   
   AXP TXO XYBO PBEO IBFZEQ WR BKQWFCCBOK, LABO KFZEQ
   
   
2. What is the plaintext for the following ciphertext that was produced using a Scytale?
   
   WDUDANCTRLUIENILIHHVUNRRGEECEOEEGSMDSEHRDRSIIEACITEESSSNISYNSMDCETDNSTEIEEHL
   
   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?
   
   9$)(/72:$719#98(+2#9$$9#!-2-:7$(4)2=2$2:?/69#$2#93=6(9!-$)(/72:$2-$)9$7:3&9$692:(
   8#6&/$7?69/)(6#9:$(33.)($)(69?2*(:93?762$)+2--(#56(76:7$$)(95$)76719:93?762$)+-9&-+
   &#2/)(62--(#56(,9:8$65-$+(29+9:(4/(6$9$$)2-9:8$7/67*($)9$29+96(93?778(4/(6$2#)933(:?
   (7$)(6(4/(6$-$712:8(*(:$)(+7-$2+/69#$2#939#98(+2#139.2:+&#2/)(6
   
   
   
4. Using a Vigenère code and the keyword enigma, determine the plaintext for this ciphertext without using the Internet:
   
   MSGUG TLVVQ ORCCB USREC PEUSX UMGZS ARZZA YSHZV DOFYM SFHIA GUGDS ABQZO AJPGF YSHZV DOFYM SUSHD
   
   
   
5. For (bored) experts: we encoded this using Vigenère code and lost the key. What might it be?
   

        GIKGE LEGHR OIGDQ PRNDL ORXMO ERLDM XEGUM QEGDV 
        OVXQW MHETI CSXKX ONMDB DAERY OBNMK CANEK KBXFI
        CTXKP DDBDW DUWDR DEGRM XDUDM WDXJS NIXQI XVXQD
        GEBEI VTWZH ORMDB DZNJY BZPZV NAPHV NEGRG RLNDW
        CEEUI BLHQI XUGCH ONDKE BTXWX XIVGX KUYFI CCAQM 
        OBXML KTMDR UOGMX ONPHV KUVGO OIGDP YELTR QPKZI
        CEGSM ORXMH SELDV DEQSM CTGTR ROYEI XTEHG RNBBL
        DZNJY BZCDH ONYZP VSDNR XTXDV WIMCI WIFJY BSONV
        QELSI VLMDR ZRHFV KMFDR DSVGP EELRI VTPDV NEG

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.