# Math 348:01 - Spring 2012

Problem 2 on the midterm asked you to identify certain strings by using data on frequency of letters in the strings and index of coincidence of various strings.

For extra credit (3 points per decrypted string, added to your exam total, up to a maximum of 15), decrypt strings A, B, C, E and F of problem 2 of the exam (D was a random string of letters). It is sufficient to find the keys and decrypt the first five words of the portion of the ciphertext which appears on the exam, but it may be useful to have the original longer ciphertexts from which the data was generated. The original strings are given below. Provide a description of your decryption attack that yields the key, with a summary of any indices, frequencies or other information that you compute, and how you applied this information. Explain carefully how you decrypted the string.

The ciphertext A) is probably the most difficult, so start with the others first.

There was an error in one line of the data provided in problem 2 (it did not influence the solution to the problem). You can earn 3 additional extra credit points by discovering the line in error and correcting it.

Turn in your solutions by classtime Friday, 3/30/12.

A)

OVATUHOAOVEETPTEALEICTHAOICDAOETTIAAOENIIIFWALTILAEGESTNSAIA SEASHEAHLACFOODCLTNEHHTRHIIHRBTONRHUHFLETSEERRGSMNDNDTUIASAE HEEAENINSNHAHOTEPTEELIHXFENOEHNTECDTITSAAEONAVSTNANIOEGENALW EEPFLAGROEVHNVTFNTOILNNANCALRBLDSDEARRERTWLRETRAOTHFLTDDHSWY HVRAIEOETAMEHHRERVTEHEFUOTIOTDTDHAELEFAOTOEOPNHEOAYORTTIWOIY CHITRDWGGITHANSVDDEAATDACDOTDLPTHTEAMEOIDHUSASOTORNOORIDTHCT APRDHIELMWENRTEOIHEHEHHWTESDTRBDOTAFAEETEOHFTTURTWGLHSHIATRL WFNVOPPRLOFACESAOTCTIIBDDONMEARDTRWHNTNNCLREAFHHTTOFFTEEGRAT TSHNPEOIRCDCNWHITMGWGHETEPDARIERWYIEWDTTGOATIOTOESBCAURTGKNU OOAIDNAHGAEDTRRHDLDIIUSETDAMEYLPARTXUNEUSFHNNNNAAETAEEWARLIE TYOEECNRGTOROIRHARLHEHSTIIGTPALBRETETANWUAVEREOEBOTEELNOBEBN GHRRVEDEUEIHHTOVIFEITTIOTSDAATAOHHLEIEHVEHANTIGHBRDEFLETETRR RDARBOIEACLNTPILCQEGEWNRINCDDADERLFWMCTASEAORETNGTETRTDUGWDW CTOTNVIAURNDOOOTWLONESUEEEEUIRIRNDCOEHNASOHCHANRFEDKSITREELO OHLESAVVTOOAIETRTEOHSPOTSSRFRRSNTEIDEROLRUAEAAGTOAOAINUMEETE EAITASCSEIHAHITIOWDTEEEEOETHDENDGESIVRAROLTGRATVTYISNTCEFWHF RUONRREAESIERHEEEOCWYLMFNEYTELEAHNDVREHNHBPEHEMHREGHGONNNERD OOHNTNENIEETROESTNWOBETVDAOENNOHVITOILRARHHAENCNECLGENNOEVRA UWOTDTOMAECFADSEAEETIKEGAAYDHTDDEEBTTOWCEOSCVTSVAHSTAOETNDANOMGNEHFOLSEX

B)

TUMDGKUDQERNGQPQRYQEDGEWUUMDTEJZQDGHDUMWZJTUDJZURJZCGKURJCRQRJER QSREJCURKURKQCPQNCRLCHQDJYERNNQNCKEJQNJUJZQXDUXUGCJCURJZEJELLOQR EDQKDQEJQNQAMELRUSSQEDQQRWEWQNCREWDQEJKCPCLSEDJQGJCRWSZQJZQDJZEJ REJCURUDERYREJCURGUKURKQCPQNERNGUNQNCKEJQNKERLURWQRNMDQSQEDQOQJU REWDQEJHEJJLQTCQLNUTJZEJSEDSQZEPQKUOQJUNQNCKEJQEXUDJCURUTJZEJTCQ LNEGETCRELDQGJCRWXLEKQTUDJZUGQSZUZQDQWEPQJZQCDLCPQGJZEJJZEJREJCU ROCWZJLCPQCJCGELJUWQJZQDTCJJCRWERNXDUXQDJZEJSQGZUMLNNUJZCGHMJCRE LEDWQDGQRGQSQKERRUJNQNCKEJQSQKERRUJKURGQKDEJQSQKERRUJZELLUSJZCGW DUMRNJZQHDEPQOQRLCPCRWERNNQENSZUGJDMWWLQNZQDQZEPQKURGQKDEJQNCJTE DEHUPQUMDXUUDXUSQDJUENNUDNQJDEKJJZQSUDLNSCLLLCJJLQRUJQRUDLURWDQO QOHQDSZEJSQGEYZQDQHMJCJKERRQPQDTUDWQJSZEJJZQYNCNZQDQCJCGTUDMGJZQ LCPCRWDEJZQDJUHQNQNCKEJQNZQDQJUJZQMRTCRCGZQNSUDISZCKZJZQYSZUTUMW ZJZQDQZEPQJZMGTEDGURUHLYENPERKQNCJCGDEJZQDTUDMGJUHQZQDQNQNCKEJQN JUJZQWDQEJJEGIDQOECRCRWHQTUDQMGJZEJTDUOJZQGQZURUDQNNQENSQJEIQCRK DQEGQNNQPUJCURJUJZEJKEMGQTUDSZCKZJZQYWEPQJZQLEGJTMLLOQEGMDQUTNQP UJCURJZEJSQZQDQZCWZLYDQGULPQJZEJJZQGQNQENGZELLRUJZEPQNCQNCRPECRJ ZEJJZCGREJCURMRNQDWUNGZELLZEPQERQSHCDJZUTTDQQNUOERNJZEJWUPQDROQR JUTJZQXQUXLQHYJZQXQUXLQTUDJZQXQUXLQGZELLRUJXQDCGZTDUOJZQQEDJZ

C)

JIWCAFSLGLVGWYXPVBIUTDIJSIWCNDXBGCAEVIWRPWJITEPRRNJTAFSHVTVHRNCYM ZRUVTWQGIPNMLZYFTVOMVGCBBEHFOMGMWCEMGXIVSMSVIRZALXCQYBKENCWTPIHC CMFVYCEMGIKWLTQSQYPIUIYPRIJIXKYIJVYCEKLZCNHIUXYUEQQKQJPBKILVSIWR UVTWQSLCYGQENKZVVSWQYKHMPGOIQHMQOMGMWCEMGGUPWWQKYPOCUIQGLZHQYVZV DKLGLBEENVWMIMYNOWIXBCEEDVQGSIYIWQXMWSXGOQFENGLXRVNKZVRJNJLBIMYN OIVEZKYIOVYUEQQKJNLKHJITEPRWYYSWKILGRIYINJPQUPCXPAWLUVEPDXHCEQRR GKRPWPCXPQWMMCWBRKYVSMUJCVEQQKUPOXUSJGCBKENYPAKSONOLRXBKDJXXCPLT DVAGCAHRMGHMFEHPZBGIXKNIWIQGNIQRIVNWQWYECIWIQGNIQRIVSIOPIYEPLWAT ZCQHNJPJUEPGXMQPCXTVJEHFOMDHQJZAWVOIRTHHBGCMKEPGNWQWYECIWIXKENDV UDZDHSOTAWRVJQHMUXICOLRVXGEZDGNVSMZSLNOELPFNTBWPYPZBHRITWWQKLGXM PFYTHPDXQGDIBLYTPJXXCVNIQRYXPZISLIPBZLUVEPHCXKOPHVYKEQVJITFAWLYN TDLRATLBKILVZJHHYFTKDXYFSMUINQEPHYHHTVLWBGOERVEYSQFLNJPGZLIHZCJL NJPZHLUXPBKYMHLZVSHQMTBEXXLVFIXKEQVVUVSMUJITFAWSVGSMUIXGOQFENGOB RXBGRZHENVLANVYOLQQMHIMMISLGFAWLUVQZRQNJPAHLIPZZHHXGLLZINCVMLRWT PIVIXFPDRXCQYBRXBCEKDYMGQWUABKNPWLYARIYINJPTDWNHFTOQYCDCUIIHOMYS NKZVWLUVHMKILGSQJLFACMVSFXPBKENVSMVIXGLLVLUNWVRXBCGMGMYFTVYECPEP DXNJTAQENKZVXRXGCORHMJLTOLUXPIQIQDTZWLIHQZHIXQXIQHNJLBJSPGCVPIHV ZNWLYRPWSPYDJBKIJGZXOIZQCBKIJGZXOIMJLTORIVAMUMMJQZRQNJPMDVNJVRL

E)

SZQRCRJZQKUMDGQUTZMOERQPQRJGCJHQKUOQGRQKQGGEDYTUDURQXQUXLQJUNCGG ULPQJZQXULCJCKELHERNGSZCKZZEPQKURRQKJQNJZQOSCJZERUJZQDERNJUEGGMO QEOURWJZQXUSQDGUTJZQQEDJZJZQGQXEDEJQERNQAMELGJEJCURJUSZCKZJZQLES GUTREJMDQERNUTREJMDQGWUNQRJCJLQJZQOENQKQRJDQGXQKJJUJZQUXCRCURGUT OERICRNDQAMCDQGJZEJJZQYGZUMLNNQKLEDQJZQKEMGQGSZCKZCOXQLJZQOJUJZQ GQXEDEJCURSQZULNJZQGQJDMJZGJUHQGQLTQPCNQRJJZEJELLOQREDQKDQEJQNQA MELJZEJJZQYEDQQRNUSQNHYJZQCDKDQEJUDSCJZKQDJECRMRELCQREHLQDCWZJGJ ZEJEOURWJZQGQEDQLCTQLCHQDJYERNJZQXMDGMCJUTZEXXCRQGGJZEJJUGQKMDQJ ZQGQDCWZJGWUPQDROQRJGEDQCRGJCJMJQNEOURWOQRNQDCPCRWJZQCDFMGJXUSQD GTDUOJZQKURGQRJUTJZQWUPQDRQNJZEJSZQRQPQDERYTUDOUTWUPQDROQRJHQKUO QGNQGJDMKJCPQUTJZQGQQRNGCJCGJZQDCWZJUTJZQXQUXLQJUELJQDUDJUEHULCG ZCJERNJUCRGJCJMJQRQSWUPQDROQRJLEYCRWCJGTUMRNEJCURURGMKZXDCRKCXLQ GERNUDWERCBCRWCJGXUSQDGCRGMKZTUDOEGJUJZQOGZELLGQQOOUGJLCIQLYJUQT TQKJJZQCDGETQJYERNZEXXCRQGGXDMNQRKQCRNQQNSCLLNCKJEJQJZEJWUPQDROQ RJGLURWQGJEHLCGZQNGZUMLNRUJHQKZERWQNTUDLCWZJERNJDERGCQRJKEMGQGER NEKKUDNCRWLYELLQVXQDCQRKQZEJZGZQSRJZEJOERICRNEDQOUDQNCGXUGQNJUGM TTQDSZCLQQPCLGED

F)

BGYQQXBGNWXVMGZNKYGCYMYIHVDQWFYEZUHWHGNMVWUTJNRVIPPXHSJNPBRHCUDW OZYVSMSSFKEQFEFDLVGWQJTKKLUXPKRRHGNBHHNJPUZMNJLVRXBGCIQHNQLAVYGG LURRAVSMSSQGCARJNJPMDVNJEPHWYRLZDXYCYLHUOCWAWENKZVWSQJTKKXBGWIZW IHYIWYLGLVGSZPLBXVYURWGIHVTBOINJPUDHYEPVWVYUAMFXNQEPHSJKYQRRMQQU DREKYLUIKWTZHWNJLBWLYADPRYFFOMFPUTPBKIWCFAHWQJTKKMGRPTWLYOEWWLYU PXDVUVTWQAYJZTGXBGDMWVOVSAWSVGDMOJYXTLHRNVSIWEFNXMQELGNZHENGOMTY UNEPDXNJPGDVYGYLRAYFMGWLYKCKUIUVZZZMNJNMUXUKYCQEFKPVDFFGCQJLNUEP DXUOZVJXBGDMDVYNTNHPCDPZWCUPOBKIJWCAXMNQQPDTJKYMVWNJLBWSMGNCUINJ PAHVCISBVKIXPZQQYPEADVYKYAWMNWEMGEGQYOPIHFPZLZCPRBKICTUCVXJQHMUW ZTZUWLYEZVVIHVZNWLYIZDHVHGOBKENYSMQIPGCIQCZQCURJAQGMURGGYBEIWQXM VHYUEZXGNKGMRJNJPAHIHFDQWMMVSMUMAJEWIXBGAMRTFGEWDPNGCWUXICMWOMMJ TBDRXVZQQWNKECWIHGHORZYTYUHRNNLGLRAKEAISOPOIWMIPZVVYWJAZLRWKATHW UPOWUKUPTHLRAKEASSQGCALRMWNPISLOLAWSNJPUVLUNWAHIGOZAWPCMPTBXIGQN HGNVSMLVMCQMWCUPOPDTJKYMVWJTFLHRWGTVGIYFHQOPXKNBDXYVSIWKIXPZQQYP EAOSHIPAWEVNTAKIXUSWXPXPZBEIWJLVJIXHZZOMAJEIQHNTLVVMYPEKDYMGDIQH UENWUHCPRTBEFNPFSILKPVFIBCEPVLYYYBKENOLVNMHFLZHQITPLLWJQDMGXIUFN IILYSQOIYXTTVELAVFC