I Norfolk State University CSC 312 Topics in IT Spring 2017

I Norfolk State University CSC 312 Topics in IT Spring 2017 Instructor: Habib M. Ammari, Ph.D. (CSE), Ph.D. (CS) Team Work 2 Date: Feb. 13, 2017 using a simple ed Problem (simple substitution Cipher: The following ciphertext is generat substitution algorithm. VBZPRUBO UKBYB FELKNwFRFIKUNUPwRFIPOUNvNIPUBRNCUKBEF FERV NBCVBPCYYFVUFO UN YVFZI RURU ZBCUIPOUNvNIPUBR XUPUNFCPWR Decipher this message based on the letter frequency table below. First Hint: As you know, the most frequently occurring letter ofthe English alphabet in English messages is e. Therefore, the most common character in the message is likely to be the letter e (frequency 13%). Moreover, the letter e is sometimes used in pairs, such as agree, bee, seed, to name a few. You should find the character in the ciphertext that corresponds to the letter e. According to the table given below, tis the second most frequent letter (frequency-9% and a is the third most frequent letter (frequency -8%). Use this information to deduce other letters. Second Hint: The most common word in English is \"the\". Try to identify the characters in the ciphertext that are associated with the letters tand h. Letter Frequency Letter Frequency 10675 0.0150 0.0751 0.0278 0.0193 D 0.0425 0.0010 E 0.0223 S 0.0633 G 0.0202 T 0.0906 H 0.069 U 0.0276 0,0098 K 00077 x 0.0015 M 0.024 0.0007 Good Luck!

Solution

CIPHER TEXT

UKBYBIPOUZBCUFEEBORUKBYBHOBBRFESPVKBWFOFERVNBCVBZPRUBO

FERVNBCVBPCYYFVUFOFEIKNWFRFIKJNUPWRFIPOUNVNIPUBRNCUKBEF

WWFDNCHXCYBOHOPYXPUBNCUBOYNRVNIWNCPOJIOFHOPZRVFZIXUBO

RJRUBZRBCHNCBBONCHRJZSFWNVRJRUBZRPCYZPUKBZPUNVPWPCYVFZI

XUPUNFCPWRVNBCVBRPYYNUNFCPWWJUKBYBIPOUZBCUIPOUNVNIPUBR

NCHOPYXPUBNCUBOYNRVNIWNCPOJIOFHOPZRNCRVNBCUNENVVFZIXUN

CHPCYVFZIXUPUNFFCPWZPUKBZPUNVR

==============================================================

PlAINTEXT:

THEDEPARTMENTOFFERSTHEDEGREESOFBACHELOROFSCIENCEMASTER
OFSCIENCEANDDOCTOROFPHILOSOPHYITALSOPARTICIPATESINTHEFO
LLOWINGUNDERGRADUATEINTERDISCIPLINARYPROGRAMSCOMPUTER
SYSTEMSENGINEERINGSYMBOLICSYSTEMSANDMATHEMATICALANDCOMP
UTATIONALSCIENCESADDITIONALLYTHEDEPARTMENTPARTICIPATES
INGRADUATEINTERDISCIPLINARYPROGRAMSINSCIENTIFICCOMPUTI
NGANDCOMPUTATIOONALMATHEMATICS


Please follow the translation :

U->T
K->H
B->E ....and So On, Using the answer you can map..i have decipherred it .


Thanks, let me know if there is any concern.