Chapters

  1. Caesar Cipher (The Beginning)
  2. Substitution Ciphers
  3. Steganography
  4. Cipher Keys (Keyboard Cipher)
  5. Keyword Alphabet
  6. Aristocrat Cipher
  7. Null Cipher
  8. Construction Principles
  9. Keyword Alphabet as a Solving Tool
  10. Patristocrat Cipher
  11. Baconian Cipher
  12. Xenocrypt Cipher
  13. Polybius Square
  14. Checkerboard Cipher
  15. Foursquare Cipher
  16. Railfence & Redefence Cipher
  17. Polyalphabetic Cipher (Quagmire)
  18. Period Determination
  19. Vigenere Cipher Type: Vigenere, Beaufort, Gronsfeld, Variant
  20. Cryptarithms
  21. Affine & Hill Ciphers
  22. Fractionated Ciphers: Fractionated Morse, Morbit, Pollux
  23. Ragbaby Cipher
  24. Route Transposition Cipher
  25. Monome-Dinome Cipher
  26. Porta Cipher
  27. Polyominoes Congruent Squares

Tyro Tutorial

An Indexed Accumulation of Fifteen Years of

Cm Tyro Grams Columns

For

The Young at Heart

And

Cryptogram Cipher Tips For

Seasoned Solvers as well as Tyro Novices

LIONEL

2015

Table of Contents

Acknowledgements

Foreword

Introduction

  1. Caesar Cipher (The Beginning)
  2. Substitution Ciphers
  3. Steganography
  4. Cipher Keys (Keyboard Cipher)
  5. Keyword Alphabet
  6. Aristocrat Cipher
  7. Null Cipher
  8. Construction Principles
  9. Keyword Alphabet as a Solving Tool
  10. Patristocrat Cipher
  11. Baconian Cipher
  12. Xenocrypt Cipher
  13. Polybius Square
  14. Checkerboard Cipher
  15. Foursquare Cipher
  16. Railfence & Redefence Cipher
  17. Polyalphabetic Cipher (Quagmire)
  18. Period Determination
  19. Vigenere Cipher Type: Vigenere, Beaufort, Gronsfeld, Variant
  20. Cryptarithms
  21. Affine & Hill Ciphers
  22. Fractionated Ciphers: Fractionated Morse, Morbit, Pollux
  23. Ragbaby Cipher
  24. Route Transposition Cipher
  25. Monome-Dinome Cipher
  26. Porta Cipher
  27. Polyominoes Congruent Squares

Appendix

  1. Aristocrat Solving Tools
  2. Patristocrat Solving Techniques
  3. Baconian Concealment Cipher
  4. Railfence Template
  5. Null Variables
  6. Affine & Hill Ciphers
  7. Foursquare CT Frequency
  8. Algorithms
  9. Google As A Solving Tool

Index

Solutions

Acknowledgements

I extend a most grateful thank you to all of the ACA Krewe through the years who have provided my intellect with all of the crypto knowledge it has been capable of absorbing and in lending their wisdom, counsel, tutelage, review and editing in support of material contained within the pages of this manuscript – Special thanks to AAJHU, BECASSE, BION, FIZZY, HONEYBEE, LEDGE, MSCREP, PHOTON, QUIPOGAM, REAL NEO and my *personal mentor, RISHU.

LIONEL                           

Foreword

The following crypto tutorial is an updated extraction from the American Cryptogram Association’s Cryptogram Tyro Grams column (initially titled Kiddee Korner) from 2000 to present. The column and these extractions have been inspired by one of the ACA’s foremost crypto mentors and educators, Gerhard Linz (LEDGE).

The American Cryptogram Association (ACA) is a non-profit organization, founded in 1929, devoted to the cultivation of cryptologic knowledge with members all over the world. It publishes a bimonthly magazine, The Cryptogram, full of hundreds of cipher types contributed by members for members’ solving pleasure. ACA cryptologist members (Krewe) mirror an image of all walks of life, representing ages from five to ninety and all trades, professions and educational levels. Nom de Plumes (Noms) bring a degree of anonymity to all members. It is fun and cryptology that counts. The Kiddee Krewe/ Young Tyros is a division of the ACA that provides a cryptology learning experience for cipher solving aspirants and has no age limitations. More information and membership details can be found at ACA’s Web site www.cryptogram.org
The Kiddee Korner had its Cryptogram (Cm) journal inception in January of 2000, changing its name to Tyro Grams in the Cm JF edition of 2003. Its intention was to provide an opening to those interested in pursuing the solving of codes and ciphers and was written to serve the Young at Heart Tyros of all ages.

Webster defines “tyro” as one who is in “the preliminary stage or rudiments of any study or occupation.” As we watched our Kiddee Krewe grow in number and skill, observe its work in solving, constructing, authoring of articles in the Cm, and watched it take part in all phases of ACA conventions, we realized that these young achievers were far removed from Kiddee Land. (Two finished with scores in the top ten at our Chicago Cipher Contest.)

We felt that we performed an injustice by labeling these youngsters and “Young at Heart” adults, eager to work at mastering the principles of cryptology as “Kiddees.”  We discouraged the young and the mature to peer at what lies beyond the Kiddee label. We also discouraged the interest of youthful membership ACA recruitment.

All of these reasons prompted us to elevate our Kiddee Krewe name to Young Tyros (tip of the hat to QUIPOGAM and Grandson, QUAZAR for their suggestion) and Kiddee Korner column to Tyro Grams. Our column objective will remain the same, that of reducing cryptology principles to their simplest terms thru a most understandable format. Appendices, cipher solution pages and an Index follow the body of this material.

LIONEL – 2015 (Lee Melair)

Introduction

Solving Rudiments

Let’s talk a bit about what our fellow hobbyists tell us has helped them develop a degree of skill and proficiency in their solving endeavors. All facets of cryptology are enjoyed – solving, constructing, writing, mentoring and above all, the friendships it generates with fellow ACA Krewe.

ANCHISES relates “I never knew LEDGE, but he took this Tyro and converted him into a solver through his excellent Novice Notes. That opus must be held in the highest regard by very many people, me included, for getting them started in the ACA with a clear exposition of how ciphers work and how one can go about solving them. Even though I solve with my computer, the solving algorithms and processes described by LEDGE for pencil and paper solving are very often the best routes for the computer to take also.”

We all begin as pencil and paper solvers and learn the basic fundamentals of the various cipher types. Those with abilities in computer operating and programming go on to utilize the computer for the elimination of a lot of the manual grunt work involved in paper and pencil solving. Much the same as an engineer, who builds structural edifices or lays out complex system designs and relies on the computer for his mathematical equations, the computer is a worthless solving aid unless the foundation of basic subject knowledge has been firmly imbedded in our minds. This said, our mission is simply to learn all we can about the makeup and idiosyncrasies of all the cipher types. 

Perhaps the best learning technique of becoming proficient in any endeavor is to cultivate an extreme interest about all of its working parts. What makes a particular “clock” or subject tick? Once you have acquired the interest and curiosity to want to know more about a subject, you will find a multitude of teachers, parents, friends, and soon to become friends, eager to impart their knowledge to you.

In our hobby, members are waiting to be of help everywhere. At the mailbox, by E-mail, at conventions and mini cons, cryptography buffs are eager to be of service. We have international (transoceanic) learning going on as we “speak.” You might be surprised at what you can learn besides cryptology.

Never underestimate the value of Google to call up our ACA Web site www.cryptogram.org or to research any term or technique which raises a question in your mind

 

Caesar Cipher (The Beginning)

We are hopeful that this column is the beginning of a long and fruitful relationship with the children (whatever the relationship) of our faithful Krewe who wish to pass this fun hobby along to another generation. We also wish for this column to be useful to all of those Young at Heart aspirants interested in developing or fine tuning their solving techniques. Continue reading Caesar Cipher (The Beginning)

Substitution Ciphers

Caesar’s cryptic messaging with a simple alphabet shift soon became obvious to the least experienced cipher analysts. A fresh approach was needed. Let’s begin to look at the world of  the simple substitution cipher where letters are randomly chosen to depict other letters of the alphabet. Randomly selecting a cipher letter (ciphertext) to represent another letter (plaintext letter) revokes the ease of simply looking for the number of shifts that a letter had been moved. Continue reading Substitution Ciphers

Cipher Keys (Keyboard Cipher)

Webster defines ‘kid’ as the informal reference to a child. I like to think of a child as an analogy to the search for knowledge and wisdom.

The child’s unquenchable thirst for answers to its never ending list of questions supports the beginning of life’s journey on the endless path of learning. “The kid in all of us” never loses the inquisitiveness for the world around us or the curiosity for what the future may hold. Continue reading Cipher Keys (Keyboard Cipher)

Keyword Alphabet

ACA Conventions are a good time to begin lifetime friendships with many people who have similar interests. They are also a wonderful opportunity to pick up a lot of information and education about cryptography. It is not coincidental that many of the Krewe solution scores have increased greatly with convention attendance.

Our ACA convention sites allow a great opportunity for ACA Krewe to plan their summer vacation setting. Conventions provide a great opportunity to get to know other members of the Young Tyros and adult members of the ACA and the cultivation of lifelong friendships.

In our last chapter, we related how most ciphers (disguised messages) are based on a key that allows both the sender and the receiver to communicate in ciphertext.

Here is a simple way to construct a substitution cipher alphabet with the use of a keyword. Pick a keyword that is easy to remember. Write the alphabet in a row of upper case letters. Write a keyword directly above it in lower case letters followed by the rest of the alphabet that does not appear in the keyword. We refer to this procedure as a Key 1 Alphabet.

zcipherabdfgjklmnogstuvwxy
ABCDEFGHIJKLMNOPQRSTUVWXYZ

You will notice that we begin our keyword over the upper case (ciphertext) letter ‘B’. If we had started our keyword above the upper case letter ‘A’, the lower case or plaintext letter ‘e’ would be substituted for by the upper case letter ‘E’ .

A letter may never be substituted for itself under ACA rules for simple substitution ciphers. When placing a plaintext keyword over the ciphertext alphabet, no identical letters may appear above or beneath each other. No letter may stand for itself (self-encryption).

A keyword may be started at any point over the ciphertext alphabet as long as it does not cause a letter to be substituted for itself.

It is equally important that duplicate letters in a keyword not be repeated, to avoid duplicate ciphertext letters standing for the same plaintext letter. Keeping these principles in mind, each keyword selected will produce different ciphertext.

The knowledge of this keyword between the sender and the receiver allows the disguised ciphertext to be converted to an easily read plaintext message. When this key is not provided the work of the cryptanalyst is ready to begin.

Indicate whether each keyword alphabet below is correct.

KW1. crazybdefghijklmnopgstuvwx
KW2. cipherabdfgjklmnogstuvwxyz
KW3. vwxyzcipherabdfgjklmnoqstu
KW4. uvwxcryptogrambdefhijklnqs
     ABCDEFGHIJKLMNOPQRSTUVWXYZ