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210 CHAPTER 10. TRANSPOSITION CIPHERS 5. Decipher the following short messages using columnar transposition based on the given keyword. (a) LTIAD IEEUU NRIER SRANI AEROR XEILO VACEE MTBOR VMUUT CO. Keyword SHARP. (b) SMAES LEHEH AUATN OIIYW CTCET RTAED SOOEK IHNOL MROGI ARGUB MS. Keyword OPENING. (c) BLWHS NNCTI EQTNF SEOET JEWRR EUIOT RTPSA HDUSE EDAEE XTOTH US. Keyword BROADWAY. (d) EWLMR RNIIH VOLEO CINLE RNAPD OGGTO CBWTT ESBHT POLIT BRSYT LE. Keyword QUICK. 6. Decrypt the following short messages enciphered using columnar transposition on full rectangles. (a) OQYHN AGEYE LGAPE SEMIN OLTAF VTUCP HDIOE OUITR RUUEY SSU. (b) AEWFU HRSLO SOLTE RIENA QTETS NTN. Hint: nulls at end. (c) HHTHM HMETS GDESU MSRED DNDFE DPXRE ODOON ITENE EIHNX EOTHI LELND DAEOX TSTOR TELNH XIAJA RLPOT. (d) LTESU AAGEO NEORE OSAGG LWERN IGDSD TNLIA TRIMD ODLLR OOTND GPNE. 7. [Hitt, pages 31–33] Since the ciphertext of transposition ciphers consist of the same letters as the plaintext, knowledge of cribs – words suspected of appearing in the plaintext – is especially helpful. Break the following 108 letter transposition cipher in which the word villa appears. HIIGF TNGHI NTCVN IEIOT CYIFY LHAEA ESNBA EEEEN RWGBN YDELR OAESG RNEBO VNLDA ICAOA LCNDT IRGVA CDOIE SEREC DVPEI AFIFL RINEH ETT 8. [HITT, pages 34-35] A weak form of double transposition uses two keywords in the following way. As usual, put the plaintext into a rectangle under the (first) keyword. The put the (second) keyword alongside the first column. Mix the plaintext by reordering the columns according the first keyword and then reordering the rows according to the second keyword. For example, to encipher radios may now be used xx with keywords S I G N S S r a d i o SIGNS and SEND, first set up the rectangle E s m a y n N o w b e u D s e d x x The first rearrangement gives I G N S S S a d i r o E m a y s n N w b e o u D e d x s x
10.13. EXERCISES 211 and the second gives I G N S S E m a y s n D e d x s x N w b e o u S a d i r o So the ciphertext is maysn edxsx wbeou adiro. The following message was enciphered using this technique. Decrypt it. Hint: The size is 7 × 10. WVGAE EGENL TFTOH TEIEF RBTSE INENG ONWRM GXIXN GOITN ROMRO ESPAL HNEAC UDNNH DERME 9. [HITT PAGE 47] Hitt considers the following slightly tricky example. LT. J. B. SMITH, Royal Flying Corps, Calais, France. DACFT RRBHA MOOUE AENOI ZTIET ASMOS EOHIE YOCKF NOHOE NOUTH OMEAH NILGO OSAHU OHOUE APCHS TLNDA CFTEN INTWN BAFOH GROHT AEIOH ABRIS ODACF TRREN OSTSM AYBIS DFTEN EFAPH OSMNI ZTIEA HLILL TWSOU GDENO UTHOM EAHBH AMOOU EAYOE QISUU OLEHA DENOE NHOOQ OBBOR TSLHO BAHEO UBHOB IHTSW ENOHO PAHIH ITUAS BIHTL Graham-White Is this a transposition or substitution cipher Explain your answer. For help, here is the frequency count. 22 11 5 6 23 7 3 26 16 0 1 8 7 15 37 3 2 7 14 18 11 0 3 0 3 2 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 10. [Plum, page 51] General Halleck wished the following cipher to be sent. Washington, 10:30am, July 15, 1863 For Genl S.A. Hurlbut, Memphis: If Gen. W.T. Sherman’s movements have sufficiently occupied the enemy to render your line safe, send all the forces you can spare to Brig.-Gen. Prentiss to operate on Price’s rear if he advances toward Missouri. H.W. Halleck, Maj.-Gen’l. His clerk, T. T. Eckert, chose McClellan as the indicator. This specifies the codewords specified in Figure 10.4. The message is to be pulled off by first starting at the bottom right-hand corner and moving up the diagonal, followed by D1, U6, D2, U5, D3, U4. In addition, there is be a null added after every six words. That is, after the diagonal, after D1, after U6, after D2, etc.. Please encipher the message.
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Cryptology: An Historical Introduct
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Contents List of Figures 8 1 Caesar
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CONTENTS 5 9 Digraphic Ciphers 167
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List of Figures 1.1 Saint Cyr Slide
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Chapter 1 Caesar Ciphers There are
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11 Examples: Encipher or decipher t
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1.1. SAINT CYR SLIDE 13 paper turne
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1.3. FREQUENCY ANALYSIS 15 PX PBEE
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1.3. FREQUENCY ANALYSIS 17 A bit mo
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1.3. FREQUENCY ANALYSIS 19 Examples
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1.4. LINQUIST’S METHOD 21 the cip
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1.7. EXERCISES 23 12. What is the m
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1.7. EXERCISES 25 (d) VTXLTKBTG LXV
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1.7. EXERCISES 27 (d) IKSUT JKIOT K
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Chapter 2 Cryptologic Terms Cryptog
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Chapter 3 The Introduction of Numbe
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3.1. THE REMAINDER OPERATOR 33 Exam
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3.1. THE REMAINDER OPERATOR 35 Perf
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3.1. THE REMAINDER OPERATOR 37 As a
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3.2. MODULAR ARITHMETIC 39 While %
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3.3. DECIMATION CIPHERS 41 previous
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3.4. DECIPHERING DECIMATION CIPHERS
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3.6. KOBLITZ’S KID-RSA AND PUBLIC
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3.6. KOBLITZ’S KID-RSA AND PUBLIC
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3.9. EXERCISES 49 8. How do we enci
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3.9. EXERCISES 51 (c) Encipher 54 4
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3.9. EXERCISES 53 (b) Encipher secr
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Chapter 4 The Euclidean Algorithm I
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4.2. GCD’S AND THE EUCLIDEAN ALGO
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4.3. MULTIPLICATIVE INVERSES 59 (2)
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4.3. MULTIPLICATIVE INVERSES 61 (2)
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4.4. DECIPHERING DECIMATION AND LIN
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4.5. BREAKING DECIMATION AND LINEAR
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4.6. SUMMARY 67 To put it more blun
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4.8. EXERCISES 69 5. Here we work w
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Chapter 5 Monoalphabetic Ciphers He
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5.2. KEYWORD MIXED CIPHERS 73 Examp
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5.4. INTERRUPTED KEYWORD CIPHERS 75
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5.6. BASIC LETTER CHARACTERISTICS 7
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5.7. ARISTOCRATS 79 the 69971 or 42
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5.9. TOPICS AND TECHNIQUES 81 5.9 T
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5.10. EXERCISES 83 (h) DYVTP KKIQ.
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5.10. EXERCISES 85 13. Ciphers in w
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5.10. EXERCISES 87 17. General Pier
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Chapter 6 Decrypting Monoalphabetic
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6.2. DECRYPTING MONOALPHABETIC CIPH
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6.3. SUKHOTIN’S METHOD FOR FINDIN
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6.4. FINAL MONOALPHABETIC TRICKS 99
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6.5. SUMMARY 101 our ciphertext muc
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6.7. EXERCISES 103 Frequency count:
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6.7. EXERCISES 105 53++!305))6*;482
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6.7. EXERCISES 107 93 93 82 48 39 6
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Chapter 7 Vigenère Ciphers It was
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7.2. TRITHEMIUS, THE FATHER OF BIBL
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7.3. BELASO, THE UNKNOWN AND PORTA,
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7.4. VIGENÈRE CIPHERS 115 to encip
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7.6. HOW TO BREAK VIGENÈRE CIPHERS
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7.6. HOW TO BREAK VIGENÈRE CIPHERS
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7.7. THE KASISKI TEST 121 Kasiski
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7.8. SUMMARY 123 Repetition Start P
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7.10. EXERCISES 125 2. Little Miss
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7.10. EXERCISES 127 to Gen. E. K. S
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7.10. EXERCISES 129 MEJMY JKXCD LCN
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7.10. EXERCISES 131 22. (a) Use Kas
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7.10. EXERCISES 133 (a) Construct a
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Chapter 8 Polyalphabetic Ciphers Th
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8.1. COINCIDENCES 137 (being born o
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8.2. THE MEASURE OF ROUGHNESS 139 I
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8.2. THE MEASURE OF ROUGHNESS 141 P
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8.3. THE FRIEDMAN TEST 143 The Frie
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8.4. MULTIPLE ENCIPHERINGS 145 Bein
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8.4. MULTIPLE ENCIPHERINGS 147 Just
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8.5. VIGENÈRE’S AUTO KEY CIPHER
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8.5. VIGENÈRE’S AUTO KEY CIPHER
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8.6. PERFECT SECRECY 153 invent now
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8.8. TERMS AND TOPICS 155 multiple
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8.9. EXERCISES 157 6. As is this on
Page 159 and 160: 8.9. EXERCISES 159 13. It has been
Page 161 and 162: 8.9. EXERCISES 161 This is Equation
Page 163 and 164: 8.9. EXERCISES 163 A: AB CDE FGH I
Page 165 and 166: 8.9. EXERCISES 165 26. Decipher SVQ
Page 167 and 168: Chapter 9 Digraphic Ciphers Althoug
Page 169 and 170: 9.1. POLYGRAPHIC CIPHERS 169 f a g
Page 171 and 172: 9.2. HILL CIPHERS 171 th 2.96 es 1.
Page 173 and 174: 9.2. HILL CIPHERS 173 We will be us
Page 175 and 176: 9.3. RECOGNIZING AND BREAKING POLYG
Page 177 and 178: 9.4. PLAYFAIR 177 Playfair Ciphers:
Page 179 and 180: 9.5. SUMMARY 179 9.5 Summary Polygr
Page 181 and 182: 9.7. EXERCISES 181 (b) The use of
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Page 187 and 188: 9.7. EXERCISES 187 The rules that W
Page 189 and 190: Chapter 10 Transposition Ciphers In
Page 191 and 192: 10.3. TURNING GRILLES 191 1 2 3 7 4
Page 193 and 194: 10.4. COLUMNAR TRANSPOSITION 193 co
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Page 197 and 198: 10.6. LETTER CONNECTIONS 197 F 2 G
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Page 213 and 214: 10.13. EXERCISES 213 evening Adam h
Page 215 and 216: 10.13. EXERCISES 215 Several codewo
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Page 219 and 220: Chapter 11 Knapsack Ciphers Merkle
Page 221 and 222: 11.3. AN EASY KNAPSACK PROBLEM 221
Page 223 and 224: 11.4. THE KNAPSACK CIPHER SYSTEM 22
Page 225 and 226: 11.4. THE KNAPSACK CIPHER SYSTEM 22
Page 227 and 228: 11.5. PUBLIC KEY CIPHER 227 Even wi
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Page 231 and 232: Chapter 12 RSA Take two large prime
Page 233 and 234: 12.1. FERMAT’S THEOREM 233 Exampl
Page 235 and 236: 12.3. COMPLICATION II: A SUBSTANTIA
Page 237 and 238: 12.3. COMPLICATION II: A SUBSTANTIA
Page 239 and 240: 12.5. COMPLICATION IV: THE LAST ONE
Page 241 and 242: 12.6. PUTTING IT ALL TOGETHER 241 1
Page 243 and 244: 12.8. RSA 243 The RSA Algorithm Set
Page 245 and 246: 12.9. RSA AND PUBLIC KEYS 245 There
Page 247 and 248: 12.10. HOW TO BREAK RSA 247 had to
Page 249 and 250: 12.12. SUMMARY 249 cannot read the
Page 251 and 252: 12.14. EXERCISES 251 6. What is a
Page 253 and 254: 12.14. EXERCISES 253 Bob is going t
Page 255 and 256: Bibliography [Antonucci] Michael An
Page 257: BIBLIOGRAPHY 257 [Shamir] [SRA] A.
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