Cryptopop's Hints

Revision E dtd 05/18/07

Introduction

    The purpose of this sub-site is to provide an abridged summary of all data pertinent to solving simple substitution cryptograms. I have tried to be as complete as possible in listing all necessary information, although from a practical standpoint, examples had to be limited. If anyone has any suggestions for improvements to this page or any questions concerning its contents, please email your comments to pwiedman@nc.rr.com

 

Frequencies

1.General Frequencies Usage

2. 1st Letter Frequencies

T,A,S,O,I,C,W,P,B,F,H,M

3. Last Letter Frequencies

E,T,S,D,N,R,Y,O,F,L,A,G

4. Double Letter Frequency

LL,EE,SS,TT,OO,MM,FF,PP,RR,NN,CC,DD

5. Digraph Frequency

th,he,in,er,an,re,on,en,at,es,ed,te,ti,or,st,ar,nd,to,
nt,is,of,it,al,as,ha,ng,co,se,me,de

      Note: 30 most frequent digraphs comprise 1/3 of all usage

6. Digraph Reversal Frequency

er-re, es-se, an-na, it-ti, on-no, en-ne, ot-to,
ed-de, st-ts, at-ta, ar-ra, in-ni

7. Trigraph Frequencies

the,and,tio,ati,for,tha,ter,res,ere,con,ted,com,hat,ent,ion,nde,has,ing

8. Small Word Frequencies

     Note: Average word length in English is 5 1/2 letters.


Specific Hints

  1. a,e,i,o,u & l,n,r,s,t comprise 70% of all word usage.
  2. Although h is slightly more frequent than l, its higher frequency is due to its occurrence in short, common words such as "the" and "that". D is somewhat more frequent than l also due mainly to -ed endings.
  3. u always follows q except in a few words of foreign extraction(e.g. Iraqi )
  4. The most frequent letter to follow a vowel is n; to precede a vowel, h.
  5. Re- and co- are the most frequent prefixes of two letters.
  6. -ion and -ing are the most frequent suffixes of three letters.
  7. -ed ,-es, -er are the most frequent endings.
  8. If a double letter can be identified followed by a vowel two letters to the right(especially e), the in-between letter is most often l.
  9. When a word begins and ends with same letter, it is most often s, t, or d. 
  10. Digraphs consisting of 2 consonants most frequently contain n or t.
  11. io, ou, & ea are the most common double-vowel digraphs.
  12. If a word begins with 2 consonants, the second letter is most likely r, l or h. 
  13. If a word ends in three consonants, it is most frequently -ght or -tch. 

Solving Methodologies

1.The major methods for breaking crypts are:

The above methodologies coupled with a strong knowledge of language and word structure(such as prefixes & suffixes) form the basis for deciphering crypts.

2. Frequencies

It is usually necessary to do various frequency counts with the more advanced type crypts. Above I have listed the most important frequency tables. Of course, a given listing does not have to be tested in exact order. Frequencies vary slightly from study to study anyhow. Intuition and experience are of far greater value in applying frequency tables.

 

3. Vowel Identification/Placement

A. Examination of short words, particularly those of 2&3 letters, is helpful in identifying vowels. Note that every word and every syllable of every word must contain at least one vowel.(exceptions: "nth" and "rhythm"-2nd syllable).

B. Examination of digraphs is useful in identifying vowels:

  1. The 30 most frequent digraphs comprise about 1/3 of all usage.
  2. About 83% of the high frequency digraphs consist of a consonant & a vowel. Two-consonant digraphs comprise almost 17% of usage while two-vowel digraphs are rare in comparison.
  3. In digraphs, vowels tend to be adjacent to consonants.
  4. Consonants with the exceptions of n and t, tend to be adjacent to vowels.
  5. If a digraph reversal is present, one letter is most likely a vowel.

C. Examination of common prefixes and suffixes is helpful in placing vowels:

  1. Since -ed, -es & -er are the most common endings, e's are often located as 2nd-to-last letters in words.
  2. Since prefixes like re- & de- are common, e's are also located as 2nd letters in words.
  3. I's are often found as 3rd-to-last letters in words due to many suffixes such as -ion, -ing , -ity, -ily, etc.
  4. Since a's are the second most frequent 1st letter, they often start words. Many prefixes beginning with a are common: "ad", "ab", "anti", etc.

D. Other

  1. A's are also often located as 2nd to last letters.
  2. E's are also often located as last letters.
  3. I's are also located as 1st letters.
  4. O's are also often located as 2nd letters and last letters.
  5. U's are often located as 1st and 2nd-to-last letters.
  6. A's and o's are often interchangeable when testing letter possibilities. If an "a" doesn't work, try an "o."

4. Pattern/High Frequency Words

Pattern words are those with distinctive letter patterns and almost always contain repetition of letters. Many pattern words are high frequency words which share common patterns with other words. High frequency and pattern words are invaluable in solving cryptoquotes and cryptoquips usually found in newspaper and magazines. Only limited examples will be given:

A. High Frequency Word Patterns

B. High Frequency Groups

C. Distinctive Word Patterns

Note: Even in this category, patterns may not be completely unique. For example, xyaxby may also = "indian" or "proper."

D. Pattern Phrases


Contractions/Possessive Case

In many cryptoquotes and cryptoquips, possessive nouns as well as contractions provide obvious clues to the solver. The apostrophe is pretty much a dead give-away when present in a cryptogram.

1. A single letter following an apostrophe in words of three or more letters is either an 's, 't or 'd.
Examples: man's (poss.), He's (cont.), don't or you'd

2. A single letter following an apostrophe in a two-letter word is 'm or 'd. Examples: I'm or I'd

3. Two different letters following an apostrophe is either 're or 've. Examples: we're or you've

4. Two of the same letter following an apostrophe is 'll. Example: she'll

5. Although rules 1-4 cover 95% of all cases, it is worth noting that occasionally relatively uncommon contractions arise including those of foreign extraction. Examples: 'tis, 'tisn't, ma'am, hors d'oeuvres, entr'acte.


Experimental Methods

The following are some ideas I have experimented with and have had fairly good success:

1. Test Word Method

If a crypt contains at least two words with several shared letters and if one of the words contain at least one repetition, use latter by guessing a word which fits its pattern and then test those letters in 2nd or 3rd words to see if reasonable possibilities form.

2. Grammatical Reconstruction

Try to establish the sentence structure of a crypt, particularly those of 3-5 words: e.g.,Adjective-Subject-Predicate-Object or Subj.-Pred.- Adv. This may help in identifying endings such as -s,-es,-ly,-ed,etc.

3. Vowel Placement Testing

Occasionally, arbitrary guessing of small words or words sharing similar letters and then "carrying thru" in the crypt may help in generally determining vowel placement or perhaps more importantly where vowels are least likely to be located.


Common Prefixes and Suffixes

Although this list does not purport to be complete, it does represent approximately 97% of the most commonly found prefixes and suffixes in standard English usage:
 
 

Prefixes

Suffixes

1  anti-  -able, -ible
2  co-, con-, com-  -al, -ial
3  de-  -ed*
4  dis-*  -en
5  en-, em-  -er
6  fore-  -est
7  in-, im-, il-, ir-*  -ful
8  inter-  -ic
9  mid-  -ily
10  mis-  -ing*
11  non-  -ion, -tion, -ation, -ition
12  over-  -ity, -ty
13  pre-  -ive, -ative, -itive
14  re-*  -less
15  semi-  -ly*
16  sub-  -ment
17  super-  -ness
18  trans-  -ous, -eous, -ious
19  un-*  -s, -es*
20  under-  -y
     

 

 * Four most common prefixes  * Four most common suffixes

Note: In addition, it is well to remember that in short crypts logical deduction plays an important role. Make likely assumptions and then follow thru to logical conclusions. This "detective work"coupled with a little perseverence is what solving crypts is all about.


Well that's about it! My notebook is exhausted as far as hints for simple substitution crypts(monoalphabets) go. I sincerely hope this has been helpful and not just a rehash of things you already knew. At the very least, it will be valuable to less experienced solvers who come across this site.

One more thing...about 10 years ago, one of the funniest cryptoquips I ever solved was published in the N.Y.H.T. Crossword Puzzle magazine. I paraphrased it below for your enjoyment:

 

     QPE UXUNQ BZ YJLBQBAO LEPT RIBYL, "BZQO ABF CZBRM PZMRLI!"   MJILRF UIBW TPICLF TPIANZ, "ABF ALYM P; OBX ALY W."