INFA 640 9040 Cryptology and Data Protection
1) (15 pts) The following is a ciphertext: U GIRJ CFJ SWAY. SWAY UR JQW GUCB-TUDDWY. SWAY UR JQW DUJJDW-BWAJQ JQAJ LYUCPR JFJAD FLDUJWYAJUFC. U NUDD SAKW GM SWAY. U NUDD EWYGUJ UJ JF EARR FOWY GW ACB JQYFIPQ GW. ACB NQWC UJ QAR PFCW EARJ U NUDD JIYC JQW UCCWY WMW JF RWW UJR EAJQ. NQWYW JQW SWAY QAR PFCW JQWYW NUDD LW CFJQUCP. FCDM U NUDD YWGAUC SYACT QWYLWY a) What kind of cipher text is this? Mono- or Poly alphabetic; [Hint: assume one and when that does not work look for the other] [1 points] b) Describe your cryptanalysis process. List all the steps you went through to decrypt the message. The steps should be in sufficient details so that a reader would be able to decrypt the encrypted text without needing any help from you. State the plain text message [the solution worked without the help from online tools will be given full credit] [If you find solution online or use online tools and if you still describe the steps by reverse engineering you will still get full credit] [If you list partial steps you will get partial credit] [12points] c) List features of the cipher- text that hindered and helped your decryption process. mention of helpful and hindering features [ 2 pts] Note: Only a decrypted message even if it is correct one without the methodology and the detailed description of the self-explanatory steps used to decrypt, would not get points.