CSC/MAT 483 – 001
Spring 2018
Test one – take-home portion
The problems are due on M 19 February
You may not collaborate.
Your solutions may be submitted electronically or as a hard copy.
Explain your approach to each problem that you do. Determine as much of the key as you can. Determine the type of cipher if you can.
You may use software that is posted on the class website, use Mathematica, use a calculator, work by hand, or use software that you wrote.
The in-class portion of the test will take place on M 12 February. That portion of the test will consist of five problems worth 6 points each. There is a maximum of 100 points.
1. (15 points) Cryptanalyze:
pnmmntayhnxwatbptjkexynhjkkcwxkxvkkexpxtgbxjjxjcythxzlmthhckchjkxddnbzpexbextbtmrsxwkexkexbvlhhxbkhckchatvenbxjnbkexbnbxkxxbkpxbknxj
The word “weaknesses” appears in the plaintext.
2. (15 points) Cryptanalyze:
GURIBL AVPUZN AHFPEV CGVFNA VYYHFG ENGRQP BQRKJU VPUJNF ZBFGYV XRYLJE VGGRAV AVGNYL QHEVAT GURSVS GRRAGU PRAGHE LNAQJU VPUQRE VIRFVG FANZRS EBZNCB YVFUOB BXFRYY REJUBQ VFPBIR ERQVGV AAVARG RRAGJR YIR
3. (15 points) Cryptanalyze:
EXJWK TMIHU XFZMF NEKTM INHEU GKXFY KGMGE TQUQL GEYYU ZOXNH MUXON MFGNK NMGMK YHWMK ZIHMX NHMYK GMGFE KLLMK ZNHMW YJUGN MZKNL JKYMG JOCMZ MOGFM XNOKJ YEJJM AMYKQ LUGMG MBMXI HMXXM KZJWE XMHUX FZMFL MZYMX NETGN UFMXN GHKBM RMMXB KYYOX KNMFN HMNZK VMYNE ZWETQ UQLGO JJXMG GMGYE XNZKG NGXEN KRJWI ONHNH KNETO XTJUM XDKNH OGOXT EZQKN OEXIK GERNK OXMFT ZEQNH MYFYI MRGON MG
4. (15 points) The following ciphertext was enciphered using a Playfair cipher. Construct the keysquare.
ZIMKB YGMQY KUEZP LAQQR UOGUI MPLKA FUNDL FRQGF FDHQI GCXPT MBHBG ZGMQB YMUOQ KUPMU KHCP
The plaintext message is:
world war two saw the use of a plethora of codes and ciphers used in a variety of situations
5. (15 points) The following ciphertext was enciphered using a Hill cipher. Construct the key and the key inverse.
KD XB YI EI IU CC
The plaintext message is: ma th ho ri zo ns