A 5 x 5 square is often suggested in the fact of a missing letter; but the fact of 26 letters does not deny one, since the careful encipherer may make use of his missing J instead of using I exclusively. Great evenness in frequencies may suggest one of the key-lengthening devices, such as autokey and progressing key; and the practical absence of repeated sequences will usually mean that a transposition has been added to a substitution. It is never a bad idea, in a puzzling example, to make the various digram-counts (in chart form): An actual digram count, in which every letter is considered the beginning of a digram; a pair-count on separated pairs, as in Playfair; the two counts which could be made with the cryptogram marked off into three-letter groups; and the kind of pair-count which could be made in Playfair if the first cryptogram-letter were omitted. Many devices, as mentioned, may be uncovered simply by “running down the alphabet.” And if the cryptogram has come from an amateur “inventor,” it may be a case of digging into one’s memory for previous “inventions.” With this last case, however, the “inventor” very often fails to submit material in proportion to the amount of complication he has introduced.

Of the examples to follow, there is none in which the system may not be learned through analysis, unless perhaps the final unnumbered cryptogram, and the material, in every case, should be suffcient for solution.

No. 163 follows Mr. Berkley’s encipherment plan, illustrated just above it.

No. 164 is said to have been taken from a German spy serving in the American army in France. This applies, however, to the first fifty groups only; the remainder was added to increase the length and to emphasize the plan followed by the spy.

No. 166 was accompanied by a plot:

“Supposed to have been found on the body of a man floating in San Diego Bay. Autopsy shows death by drowning. Victim was a local banker who had disappeared a few days earlier. Wife says no financial worries. No money missing. Banker had prospered during depression. Was yachting enthusiast. Our hero solved the cipher with the unconscious assistance of a radio crooner. Tragedy occurred in August, 1932.” The date was doubly underscored, but those who have read the message have found no reason for this and no explanation for the “crooner.”

157. By PICCOLA.
C S R Z V Y P Q Z J K H K V Q U U C V M R T W Z N G H Q S A K O X P M
H D R W A J D F Q D F S R Z Z C G X P A J J T Z U L H T G S A H X J J
L T R N N Z P B Z G R E B N F Y G E J N M T N J J Q H P J X M O B J A
L X I A I C P F J O O F R N H.
158. By PICCOLA.
O C E E A T T I T K S N D T D S T H O O Y E A O E E P E B O T Y T A O
A D S E O E T F T T T H R V W C T H O Y L T O O H L R B T T U H R R V
R A W O B R U A O Y E H H L A B N E R L R K V C R I O N S E I D R U E
R I P.
159. By TITOGI.
A H Y N U H C E S T I T N D O R F E H R W E A T F N R F P A O T M A T
L H R E I O T N R L O D R H E E A T E S C T D I N W T S T O E A T S I
T E C D U T M S O T R L D O N G N I I S O F A E T L I T A S.
160. By PICCOLA. (Veiled reference to crypt No. 166?)
(a) H Z M Q L D N N D Z S P R F S K L L L L. (b) L I L V M S T Z U G
D H Z U Q X L L L L. (c) T V I U M F R U O Y U Q Y P S F W X L L.
(d) L I L V M F P O E Y Z K F D V U E L L L. (e) G K P V D Z T A Y T
B F Y Y C F I U L L. (f) Q B F P W Y C L U D V P Z Z O S W Y N C.
(g) Q B R T F F G V T U E N S Z H B Q E R L.
161. By PICCOLA.
E G W G W G E G T U C L C U O X G K Z T E G O B G B Y L W M I Q N K Q
Y E N F S C L H M N Y B X S E T N I W O C E G C B F C T C S Z T V G B
E A E G T U R K F K B E G K X B C T G Z Y L X C H Y E G C U O X Y T Q
F A D Q T T C U N B O G C O H X C E W E C U V E G C O C X Y X G B E A
Y T K X F Q C O T B X N E G T U C O N T O P E L E K U V U N T O C N G
N G B K W C E E C S Z K W N H E I K C C R E G C T E G T U R K F K T B
R G M W X C F G Q N I C E B P E E W E N B K I Y F K F D O F E G N U C
B G M T Z T F X C E W E C F V D T T U Z T E N E G W G L F M C T O V L.
162. By PICCOLA.
S P P A S T A S E F U N M T E H S O O A E S L E I C T R C H V U G S E
L Y R E M E N E E R O S N E H I R A E T O R N S H M O D R O P E A O R
P O S R Y P D O I N O C K G T.

The "NICODEMUS" Cipher (Harold Berkley) SPECIMEN ENCIPHERMENT
Key: M E T H O D I C M E T H O D I C M E T...
6 3 8 4 7 2 5 1 6 3 8 4 7 2 5 1 6 3 8...
Cryptogram:
T H I S I S E N A N S P O S E D E T C...
C I P H E R E D U S I N G T H E PFGVT VUHDG LMRIV
I V V I G E N E S A M E K E Y F ZOPUH MMVNB FOUDQ WSURF
R E A N D A F T O R B O T H O P BIOTP FGHRU VWHKR RWEVV
E R W A R D T R E R A T I O N S WULVA MPGWV MGEAQ CUYHW LBFUT.
163. By PICCOLA.
T Y D Q V W P A Z O M B W B I R K F I O O G W C O G E F L T Q M S R F
X T C J C M A W P P Q M E X V O Q C O C Z F S F W V F E V E R S A B E
C V J J W S I P P H M M K O X V Y I D B D B C I S Y N L J C Y F K C W
E N Z E I T J V L Z M I L I I R W K R O O S Z A W E K J V J G F M Q K
G F N C K H P B R D L V I A P E S L V M D J Z Z V F Z F F R D B A D P
Q W E N L A L O E K M F M F W X O K D W D G C K K K C Q R V.
164. By VULPUS.
P E N A R C P F T I Q E V A T E N B L A T K Q F O A R E N E U I P E P
F U K X I L C N F Q E P C V B T A W A O B N C O E T I N D W B N A R D
Q F O F N B V C P E P G V G P A V A P B P F O A O B S C L B V B T F W
A N E W B T C S D N F M A N A O E V A R A R C T K Q E N B M B Q F V E
V B X K O A P E T B U I P F O F Q E L E O B R D R B Q F U A W A S C U
K L F P E W B O C O D N A M E L G V F V A N C N D M F N B V D T D L E
P F V I T I Q E Q F O C O A U C L F L A O B M E P E N A S D L B T K L
H N E P D. ..... U I L A L B O B M A V K M G U K R F P F U B U D M
F W E T A T I Q E V B R C M B W A N F Z I L E N A Q F W B T C R D T B
T K O E P E U A V A O F N B S C Z K V B W C U B O A L F O B M E X I T
D Q C Q D W A P F Q E N A L A.
165. By PICCOLA. (Again that No. 166?)